diff --git a/BUILD b/BUILD
index 25b26b7b244..d612d9c1ea4 100644
--- a/BUILD
+++ b/BUILD
@@ -51,6 +51,7 @@ cc_library(
     "src/core/support/string.h",
     "src/core/support/string_win32.h",
     "src/core/support/thd_internal.h",
+    "src/core/support/time_precise.h",
     "src/core/support/alloc.c",
     "src/core/support/cmdline.c",
     "src/core/support/cpu_iphone.c",
@@ -208,7 +209,6 @@ cc_library(
     "src/core/json/json_reader.h",
     "src/core/json/json_writer.h",
     "src/core/profiling/timers.h",
-    "src/core/profiling/timers_preciseclock.h",
     "src/core/statistics/census_interface.h",
     "src/core/statistics/census_rpc_stats.h",
     "src/core/surface/byte_buffer_queue.h",
@@ -477,7 +477,6 @@ cc_library(
     "src/core/json/json_reader.h",
     "src/core/json/json_writer.h",
     "src/core/profiling/timers.h",
-    "src/core/profiling/timers_preciseclock.h",
     "src/core/statistics/census_interface.h",
     "src/core/statistics/census_rpc_stats.h",
     "src/core/surface/byte_buffer_queue.h",
@@ -992,6 +991,7 @@ objc_library(
     "src/core/support/string.h",
     "src/core/support/string_win32.h",
     "src/core/support/thd_internal.h",
+    "src/core/support/time_precise.h",
   ],
   includes = [
     "include",
@@ -1232,7 +1232,6 @@ objc_library(
     "src/core/json/json_reader.h",
     "src/core/json/json_writer.h",
     "src/core/profiling/timers.h",
-    "src/core/profiling/timers_preciseclock.h",
     "src/core/statistics/census_interface.h",
     "src/core/statistics/census_rpc_stats.h",
     "src/core/surface/byte_buffer_queue.h",
diff --git a/Makefile b/Makefile
index 6d857c588b6..f902cfcfb72 100644
--- a/Makefile
+++ b/Makefile
@@ -1651,8 +1651,8 @@ else
 	$(Q)(cd third_party/openssl ; CC="$(CC) $(PIC_CPPFLAGS) -fvisibility=hidden $(CPPFLAGS_$(CONFIG)) $(OPENSSL_CFLAGS_$(CONFIG)) $(OPENSSL_CFLAGS_EXTRA)" ./config no-asm $(OPENSSL_CONFIG_$(CONFIG)))
 endif
 endif
-	$(Q)$(MAKE) -C third_party/openssl clean
-	$(Q)(unset CPPFLAGS; $(MAKE) -C third_party/openssl build_crypto build_ssl)
+	$(Q)$(MAKE) -j 1 -C third_party/openssl clean
+	$(Q)(unset CPPFLAGS; $(MAKE) -j 1 -C third_party/openssl build_crypto build_ssl)
 	$(Q)mkdir -p $(LIBDIR)/$(CONFIG)/openssl
 	$(Q)cp third_party/openssl/libssl.a third_party/openssl/libcrypto.a $(LIBDIR)/$(CONFIG)/openssl
 
@@ -4794,6 +4794,7 @@ LIBGRPC++_TEST_UTIL_SRC = \
     $(GENDIR)/test/cpp/util/echo_duplicate.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.grpc.pb.cc \
     test/cpp/util/cli_call.cc \
     test/cpp/util/create_test_channel.cc \
+    test/cpp/util/string_ref_helper.cc \
     test/cpp/util/subprocess.cc \
 
 
@@ -4840,6 +4841,7 @@ endif
 endif
 $(OBJDIR)/$(CONFIG)/test/cpp/util/cli_call.o: $(GENDIR)/test/cpp/util/messages.pb.cc $(GENDIR)/test/cpp/util/messages.grpc.pb.cc $(GENDIR)/test/cpp/util/echo.pb.cc $(GENDIR)/test/cpp/util/echo.grpc.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.grpc.pb.cc
 $(OBJDIR)/$(CONFIG)/test/cpp/util/create_test_channel.o: $(GENDIR)/test/cpp/util/messages.pb.cc $(GENDIR)/test/cpp/util/messages.grpc.pb.cc $(GENDIR)/test/cpp/util/echo.pb.cc $(GENDIR)/test/cpp/util/echo.grpc.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.grpc.pb.cc
+$(OBJDIR)/$(CONFIG)/test/cpp/util/string_ref_helper.o: $(GENDIR)/test/cpp/util/messages.pb.cc $(GENDIR)/test/cpp/util/messages.grpc.pb.cc $(GENDIR)/test/cpp/util/echo.pb.cc $(GENDIR)/test/cpp/util/echo.grpc.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.grpc.pb.cc
 $(OBJDIR)/$(CONFIG)/test/cpp/util/subprocess.o: $(GENDIR)/test/cpp/util/messages.pb.cc $(GENDIR)/test/cpp/util/messages.grpc.pb.cc $(GENDIR)/test/cpp/util/echo.pb.cc $(GENDIR)/test/cpp/util/echo.grpc.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.pb.cc $(GENDIR)/test/cpp/util/echo_duplicate.grpc.pb.cc
 
 
@@ -20702,6 +20704,7 @@ test/cpp/qps/timer.cc: $(OPENSSL_DEP)
 test/cpp/util/benchmark_config.cc: $(OPENSSL_DEP)
 test/cpp/util/cli_call.cc: $(OPENSSL_DEP)
 test/cpp/util/create_test_channel.cc: $(OPENSSL_DEP)
+test/cpp/util/string_ref_helper.cc: $(OPENSSL_DEP)
 test/cpp/util/subprocess.cc: $(OPENSSL_DEP)
 test/cpp/util/test_config.cc: $(OPENSSL_DEP)
 endif
diff --git a/build.json b/build.json
index 1efaafdb52d..bee09831d77 100644
--- a/build.json
+++ b/build.json
@@ -181,7 +181,6 @@
         "src/core/json/json_reader.h",
         "src/core/json/json_writer.h",
         "src/core/profiling/timers.h",
-        "src/core/profiling/timers_preciseclock.h",
         "src/core/statistics/census_interface.h",
         "src/core/statistics/census_rpc_stats.h",
         "src/core/surface/byte_buffer_queue.h",
@@ -404,7 +403,8 @@
         "src/core/support/stack_lockfree.h",
         "src/core/support/string.h",
         "src/core/support/string_win32.h",
-        "src/core/support/thd_internal.h"
+        "src/core/support/thd_internal.h",
+        "src/core/support/time_precise.h"
       ],
       "src": [
         "src/core/support/alloc.c",
@@ -663,6 +663,7 @@
       "headers": [
         "test/cpp/util/cli_call.h",
         "test/cpp/util/create_test_channel.h",
+        "test/cpp/util/string_ref_helper.h",
         "test/cpp/util/subprocess.h"
       ],
       "src": [
@@ -671,6 +672,7 @@
         "test/cpp/util/echo_duplicate.proto",
         "test/cpp/util/cli_call.cc",
         "test/cpp/util/create_test_channel.cc",
+        "test/cpp/util/string_ref_helper.cc",
         "test/cpp/util/subprocess.cc"
       ],
       "deps": [
diff --git a/gRPC.podspec b/gRPC.podspec
index f6d09dbaa62..55f72c93d88 100644
--- a/gRPC.podspec
+++ b/gRPC.podspec
@@ -68,6 +68,7 @@ Pod::Spec.new do |s|
                       'src/core/support/grpc_string.h',
                       'src/core/support/string_win32.h',
                       'src/core/support/thd_internal.h',
+                      'src/core/support/time_precise.h',
                       'grpc/support/alloc.h',
                       'grpc/support/atm.h',
                       'grpc/support/atm_gcc_atomic.h',
@@ -210,7 +211,6 @@ Pod::Spec.new do |s|
                       'src/core/json/json_reader.h',
                       'src/core/json/json_writer.h',
                       'src/core/profiling/timers.h',
-                      'src/core/profiling/timers_preciseclock.h',
                       'src/core/statistics/census_interface.h',
                       'src/core/statistics/census_rpc_stats.h',
                       'src/core/surface/byte_buffer_queue.h',
@@ -404,6 +404,7 @@ Pod::Spec.new do |s|
                               'src/core/support/string.h',
                               'src/core/support/string_win32.h',
                               'src/core/support/thd_internal.h',
+                              'src/core/support/time_precise.h',
                               'src/core/security/auth_filters.h',
                               'src/core/security/base64.h',
                               'src/core/security/credentials.h',
@@ -482,7 +483,6 @@ Pod::Spec.new do |s|
                               'src/core/json/json_reader.h',
                               'src/core/json/json_writer.h',
                               'src/core/profiling/timers.h',
-                              'src/core/profiling/timers_preciseclock.h',
                               'src/core/statistics/census_interface.h',
                               'src/core/statistics/census_rpc_stats.h',
                               'src/core/surface/byte_buffer_queue.h',
diff --git a/include/grpc++/client_context.h b/include/grpc++/client_context.h
index 29d4d96723b..e9453e6078d 100644
--- a/include/grpc++/client_context.h
+++ b/include/grpc++/client_context.h
@@ -58,6 +58,7 @@
 #include <grpc++/support/auth_context.h>
 #include <grpc++/support/config.h>
 #include <grpc++/support/status.h>
+#include <grpc++/support/string_ref.h>
 #include <grpc++/support/time.h>
 
 struct census_context;
@@ -184,8 +185,8 @@ class ClientContext {
   /// ClientReaderInterface::WaitForInitialMetadata().
   ///
   /// \return A multimap of initial metadata key-value pairs from the server.
-  const std::multimap<grpc::string, grpc::string>& GetServerInitialMetadata() {
-    // TODO(dgq): is this really an assert? Why not return an empty multimap?
+  const std::multimap<grpc::string_ref, grpc::string_ref>&
+  GetServerInitialMetadata() {
     GPR_ASSERT(initial_metadata_received_);
     return recv_initial_metadata_;
   }
@@ -196,7 +197,8 @@ class ClientContext {
   /// \warning This method is only callable once the stream has finished.
   ///
   /// \return A multimap of metadata trailing key-value pairs from the server.
-  const std::multimap<grpc::string, grpc::string>& GetServerTrailingMetadata() {
+  const std::multimap<grpc::string_ref, grpc::string_ref>&
+  GetServerTrailingMetadata() {
     // TODO(yangg) check finished
     return trailing_metadata_;
   }
@@ -318,8 +320,8 @@ class ClientContext {
   mutable std::shared_ptr<const AuthContext> auth_context_;
   struct census_context* census_context_;
   std::multimap<grpc::string, grpc::string> send_initial_metadata_;
-  std::multimap<grpc::string, grpc::string> recv_initial_metadata_;
-  std::multimap<grpc::string, grpc::string> trailing_metadata_;
+  std::multimap<grpc::string_ref, grpc::string_ref> recv_initial_metadata_;
+  std::multimap<grpc::string_ref, grpc::string_ref> trailing_metadata_;
 
   grpc_call* propagate_from_call_;
   PropagationOptions propagation_options_;
diff --git a/include/grpc++/impl/call.h b/include/grpc++/impl/call.h
index e5da6c9e2af..fca56030479 100644
--- a/include/grpc++/impl/call.h
+++ b/include/grpc++/impl/call.h
@@ -54,8 +54,9 @@ namespace grpc {
 class ByteBuffer;
 class Call;
 
-void FillMetadataMap(grpc_metadata_array* arr,
-                     std::multimap<grpc::string, grpc::string>* metadata);
+void FillMetadataMap(
+    grpc_metadata_array* arr,
+    std::multimap<grpc::string_ref, grpc::string_ref>* metadata);
 grpc_metadata* FillMetadataArray(
     const std::multimap<grpc::string, grpc::string>& metadata);
 
@@ -418,7 +419,7 @@ class CallOpRecvInitialMetadata {
   }
 
  private:
-  std::multimap<grpc::string, grpc::string>* recv_initial_metadata_;
+  std::multimap<grpc::string_ref, grpc::string_ref>* recv_initial_metadata_;
   grpc_metadata_array recv_initial_metadata_arr_;
 };
 
@@ -461,7 +462,7 @@ class CallOpClientRecvStatus {
   }
 
  private:
-  std::multimap<grpc::string, grpc::string>* recv_trailing_metadata_;
+  std::multimap<grpc::string_ref, grpc::string_ref>* recv_trailing_metadata_;
   Status* recv_status_;
   grpc_metadata_array recv_trailing_metadata_arr_;
   grpc_status_code status_code_;
diff --git a/include/grpc++/server_context.h b/include/grpc++/server_context.h
index ce3cb47a237..4b17a280471 100644
--- a/include/grpc++/server_context.h
+++ b/include/grpc++/server_context.h
@@ -41,6 +41,7 @@
 #include <grpc/support/time.h>
 #include <grpc++/support/auth_context.h>
 #include <grpc++/support/config.h>
+#include <grpc++/support/string_ref.h>
 #include <grpc++/support/time.h>
 
 struct gpr_timespec;
@@ -103,7 +104,7 @@ class ServerContext {
 
   bool IsCancelled() const;
 
-  const std::multimap<grpc::string, grpc::string>& client_metadata() {
+  const std::multimap<grpc::string_ref, grpc::string_ref>& client_metadata() {
     return client_metadata_;
   }
 
@@ -185,7 +186,7 @@ class ServerContext {
   CompletionQueue* cq_;
   bool sent_initial_metadata_;
   mutable std::shared_ptr<const AuthContext> auth_context_;
-  std::multimap<grpc::string, grpc::string> client_metadata_;
+  std::multimap<grpc::string_ref, grpc::string_ref> client_metadata_;
   std::multimap<grpc::string, grpc::string> initial_metadata_;
   std::multimap<grpc::string, grpc::string> trailing_metadata_;
 
diff --git a/include/grpc++/support/string_ref.h b/include/grpc++/support/string_ref.h
index 0ec39a9b0a6..fd2b3ad8e7b 100644
--- a/include/grpc++/support/string_ref.h
+++ b/include/grpc++/support/string_ref.h
@@ -35,6 +35,7 @@
 #define GRPCXX_STRING_REF_H
 
 #include <iterator>
+#include <iosfwd>
 
 #include <grpc++/support/config.h>
 
@@ -50,22 +51,22 @@ class string_ref {
   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
 
   // constants
-  static constexpr size_t npos = size_t(-1);
+  const static size_t npos = size_t(-1);
 
   // construct/copy.
-  constexpr string_ref() : data_(nullptr), length_(0) {}
-  constexpr string_ref(const string_ref& other)
+  string_ref() : data_(nullptr), length_(0) {}
+  string_ref(const string_ref& other)
       : data_(other.data_), length_(other.length_) {}
   string_ref& operator=(const string_ref& rhs);
   string_ref(const char* s);
-  constexpr string_ref(const char* s, size_t l) : data_(s), length_(l) {}
+  string_ref(const char* s, size_t l) : data_(s), length_(l) {}
   string_ref(const grpc::string& s) : data_(s.data()), length_(s.length()) {}
 
   // iterators
-  constexpr const_iterator begin() const { return data_; }
-  constexpr const_iterator end() const { return data_ + length_; }
-  constexpr const_iterator cbegin() const { return data_; }
-  constexpr const_iterator cend() const { return data_ + length_; }
+  const_iterator begin() const { return data_; }
+  const_iterator end() const { return data_ + length_; }
+  const_iterator cbegin() const { return data_; }
+  const_iterator cend() const { return data_ + length_; }
   const_reverse_iterator rbegin() const {
     return const_reverse_iterator(end());
   }
@@ -80,10 +81,10 @@ class string_ref {
   }
 
   // capacity
-  constexpr size_t size() const { return length_; }
-  constexpr size_t length() const { return length_; }
-  constexpr size_t max_size() const { return length_; }
-  constexpr bool empty() const { return length_ == 0; }
+  size_t size() const { return length_; }
+  size_t length() const { return length_; }
+  size_t max_size() const { return length_; }
+  bool empty() const { return length_ == 0; }
 
   // element access
   const char* data() const { return data_; }
@@ -95,9 +96,7 @@ class string_ref {
   size_t find(string_ref s) const;
   size_t find(char c) const;
 
-  // Defined as constexpr in n3442 but C++11 constexpr semantics do not allow
-  // the implementation of this function to comply.
-  /* constrexpr */ string_ref substr(size_t pos, size_t n = npos) const;
+  string_ref substr(size_t pos, size_t n = npos) const;
 
  private:
   const char* data_;
@@ -112,6 +111,8 @@ bool operator>(string_ref x, string_ref y);
 bool operator<=(string_ref x, string_ref y);
 bool operator>=(string_ref x, string_ref y);
 
+std::ostream& operator<<(std::ostream& stream, const string_ref& string);
+
 }  // namespace grpc
 
 #endif  // GRPCXX_STRING_REF_H
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index 101fc88d8f6..145052b6d3c 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -134,6 +134,14 @@ typedef struct {
 /** Secondary user agent: goes at the end of the user-agent metadata
     sent on each request */
 #define GRPC_ARG_SECONDARY_USER_AGENT_STRING "grpc.secondary_user_agent"
+/* The caller of the secure_channel_create functions may override the target
+   name used for SSL host name checking using this channel argument which is of
+   type GRPC_ARG_STRING. This *should* be used for testing only.
+   If this argument is not specified, the name used for SSL host name checking
+   will be the target parameter (assuming that the secure channel is an SSL
+   channel). If this parameter is specified and the underlying is not an SSL
+   channel, it will just be ignored. */
+#define GRPC_SSL_TARGET_NAME_OVERRIDE_ARG "grpc.ssl_target_name_override"
 
 /** Connectivity state of a channel. */
 typedef enum {
diff --git a/include/grpc/grpc_security.h b/include/grpc/grpc_security.h
index 7f8f4d4a053..de565b2d2fc 100644
--- a/include/grpc/grpc_security.h
+++ b/include/grpc/grpc_security.h
@@ -142,15 +142,6 @@ grpc_credentials *grpc_iam_credentials_create(const char *authorization_token,
 
 /* --- Secure channel creation. --- */
 
-/* The caller of the secure_channel_create functions may override the target
-   name used for SSL host name checking using this channel argument which is of
-   type GRPC_ARG_STRING. This *should* be used for testing only.
-   If this argument is not specified, the name used for SSL host name checking
-   will be the target parameter (assuming that the secure channel is an SSL
-   channel). If this parameter is specified and the underlying is not an SSL
-   channel, it will just be ignored. */
-#define GRPC_SSL_TARGET_NAME_OVERRIDE_ARG "grpc.ssl_target_name_override"
-
 /* Creates a secure channel using the passed-in credentials. */
 grpc_channel *grpc_secure_channel_create(grpc_credentials *creds,
                                          const char *target,
diff --git a/include/grpc/support/time.h b/include/grpc/support/time.h
index 4ef9c764592..f8ed893bc02 100644
--- a/include/grpc/support/time.h
+++ b/include/grpc/support/time.h
@@ -52,6 +52,9 @@ typedef enum {
   /* Realtime clock. May jump forwards or backwards. Settable by
      the system administrator. Has its epoch at 0:00:00 UTC 1 Jan 1970. */
   GPR_CLOCK_REALTIME,
+  /* CPU cycle time obtained by rdtsc instruction on x86 platforms. Epoch
+     undefined. Degrades to GPR_CLOCK_REALTIME on other platforms. */
+  GPR_CLOCK_PRECISE,
   /* Unmeasurable clock type: no base, created by taking the difference
      between two times */
   GPR_TIMESPAN
diff --git a/src/core/channel/http_client_filter.c b/src/core/channel/http_client_filter.c
index 48c623d3591..2b61d33c29d 100644
--- a/src/core/channel/http_client_filter.c
+++ b/src/core/channel/http_client_filter.c
@@ -45,7 +45,6 @@ typedef struct call_data {
   grpc_linked_mdelem content_type;
   grpc_linked_mdelem user_agent;
   int sent_initial_metadata;
-  int sent_authority;
 
   int got_initial_metadata;
   grpc_stream_op_buffer *recv_ops;
@@ -64,7 +63,6 @@ typedef struct channel_data {
   grpc_mdelem *scheme;
   grpc_mdelem *content_type;
   grpc_mdelem *status;
-  grpc_mdelem *default_authority;
   /** complete user agent mdelem */
   grpc_mdelem *user_agent;
 } channel_data;
@@ -103,7 +101,6 @@ static void hc_on_recv(void *user_data, int success) {
 
 static grpc_mdelem *client_strip_filter(void *user_data, grpc_mdelem *md) {
   grpc_call_element *elem = user_data;
-  call_data *calld = elem->call_data;
   channel_data *channeld = elem->channel_data;
   /* eat the things we'd like to set ourselves */
   if (md->key == channeld->method->key) return NULL;
@@ -111,10 +108,6 @@ static grpc_mdelem *client_strip_filter(void *user_data, grpc_mdelem *md) {
   if (md->key == channeld->te_trailers->key) return NULL;
   if (md->key == channeld->content_type->key) return NULL;
   if (md->key == channeld->user_agent->key) return NULL;
-  if (channeld->default_authority &&
-      channeld->default_authority->key == md->key) {
-    calld->sent_authority = 1;
-  }
   return md;
 }
 
@@ -138,11 +131,6 @@ static void hc_mutate_op(grpc_call_element *elem,
                                    GRPC_MDELEM_REF(channeld->method));
       grpc_metadata_batch_add_head(&op->data.metadata, &calld->scheme,
                                    GRPC_MDELEM_REF(channeld->scheme));
-      if (channeld->default_authority && !calld->sent_authority) {
-        grpc_metadata_batch_add_head(
-            &op->data.metadata, &calld->authority,
-            GRPC_MDELEM_REF(channeld->default_authority));
-      }
       grpc_metadata_batch_add_tail(&op->data.metadata, &calld->te_trailers,
                                    GRPC_MDELEM_REF(channeld->te_trailers));
       grpc_metadata_batch_add_tail(&op->data.metadata, &calld->content_type,
@@ -175,7 +163,6 @@ static void init_call_elem(grpc_call_element *elem,
   call_data *calld = elem->call_data;
   calld->sent_initial_metadata = 0;
   calld->got_initial_metadata = 0;
-  calld->sent_authority = 0;
   calld->on_done_recv = NULL;
   grpc_iomgr_closure_init(&calld->hc_on_recv, hc_on_recv, elem);
   if (initial_op) hc_mutate_op(elem, initial_op);
@@ -257,8 +244,6 @@ static grpc_mdstr *user_agent_from_args(grpc_mdctx *mdctx,
 static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *channel_args,
                               grpc_mdctx *mdctx, int is_first, int is_last) {
-  size_t i;
-
   /* grab pointers to our data from the channel element */
   channel_data *channeld = elem->channel_data;
 
@@ -267,21 +252,6 @@ static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
      path */
   GPR_ASSERT(!is_last);
 
-  channeld->default_authority = NULL;
-  if (channel_args) {
-    for (i = 0; i < channel_args->num_args; i++) {
-      if (0 == strcmp(channel_args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
-        if (channel_args->args[i].type != GRPC_ARG_STRING) {
-          gpr_log(GPR_ERROR, "%s: must be an string",
-                  GRPC_ARG_DEFAULT_AUTHORITY);
-        } else {
-          channeld->default_authority = grpc_mdelem_from_strings(
-              mdctx, ":authority", channel_args->args[i].value.string);
-        }
-      }
-    }
-  }
-
   /* initialize members */
   channeld->te_trailers = grpc_mdelem_from_strings(mdctx, "te", "trailers");
   channeld->method = grpc_mdelem_from_strings(mdctx, ":method", "POST");
@@ -306,9 +276,6 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
   GRPC_MDELEM_UNREF(channeld->content_type);
   GRPC_MDELEM_UNREF(channeld->status);
   GRPC_MDELEM_UNREF(channeld->user_agent);
-  if (channeld->default_authority) {
-    GRPC_MDELEM_UNREF(channeld->default_authority);
-  }
 }
 
 const grpc_channel_filter grpc_http_client_filter = {
diff --git a/src/core/client_config/resolver_factory.c b/src/core/client_config/resolver_factory.c
index 6721977e21a..5b859a8d10b 100644
--- a/src/core/client_config/resolver_factory.c
+++ b/src/core/client_config/resolver_factory.c
@@ -45,6 +45,12 @@ void grpc_resolver_factory_unref(grpc_resolver_factory *factory) {
 grpc_resolver *grpc_resolver_factory_create_resolver(
     grpc_resolver_factory *factory, grpc_uri *uri,
     grpc_subchannel_factory *subchannel_factory) {
-  if (!factory) return NULL;
+  if (factory == NULL) return NULL;
   return factory->vtable->create_resolver(factory, uri, subchannel_factory);
 }
+
+char *grpc_resolver_factory_get_default_authority(
+    grpc_resolver_factory *factory, grpc_uri *uri) {
+  if (factory == NULL) return NULL;
+  return factory->vtable->get_default_authority(factory, uri);
+}
diff --git a/src/core/client_config/resolver_factory.h b/src/core/client_config/resolver_factory.h
index c5d85499c6e..e243b23988a 100644
--- a/src/core/client_config/resolver_factory.h
+++ b/src/core/client_config/resolver_factory.h
@@ -51,9 +51,16 @@ struct grpc_resolver_factory_vtable {
   void (*ref)(grpc_resolver_factory *factory);
   void (*unref)(grpc_resolver_factory *factory);
 
+  /** Implementation of grpc_resolver_factory_create_resolver */
   grpc_resolver *(*create_resolver)(
       grpc_resolver_factory *factory, grpc_uri *uri,
       grpc_subchannel_factory *subchannel_factory);
+
+  /** Implementation of grpc_resolver_factory_get_default_authority */
+  char *(*get_default_authority)(grpc_resolver_factory *factory, grpc_uri *uri);
+
+  /** URI scheme that this factory implements */
+  const char *scheme;
 };
 
 void grpc_resolver_factory_ref(grpc_resolver_factory *resolver);
@@ -64,4 +71,9 @@ grpc_resolver *grpc_resolver_factory_create_resolver(
     grpc_resolver_factory *factory, grpc_uri *uri,
     grpc_subchannel_factory *subchannel_factory);
 
+/** Return a (freshly allocated with gpr_malloc) string representing
+    the default authority to use for this scheme. */
+char *grpc_resolver_factory_get_default_authority(
+    grpc_resolver_factory *factory, grpc_uri *uri);
+
 #endif /* GRPC_INTERNAL_CORE_CONFIG_RESOLVER_FACTORY_H */
diff --git a/src/core/client_config/resolver_registry.c b/src/core/client_config/resolver_registry.c
index 16be2da9940..37979b3b86c 100644
--- a/src/core/client_config/resolver_registry.c
+++ b/src/core/client_config/resolver_registry.c
@@ -41,41 +41,33 @@
 
 #define MAX_RESOLVERS 10
 
-typedef struct {
-  char *scheme;
-  grpc_resolver_factory *factory;
-} registered_resolver;
-
-static registered_resolver g_all_of_the_resolvers[MAX_RESOLVERS];
+static grpc_resolver_factory *g_all_of_the_resolvers[MAX_RESOLVERS];
 static int g_number_of_resolvers = 0;
 
-static char *g_default_resolver_scheme;
+static char *g_default_resolver_prefix;
 
-void grpc_resolver_registry_init(const char *default_resolver_scheme) {
+void grpc_resolver_registry_init(const char *default_resolver_prefix) {
   g_number_of_resolvers = 0;
-  g_default_resolver_scheme = gpr_strdup(default_resolver_scheme);
+  g_default_resolver_prefix = gpr_strdup(default_resolver_prefix);
 }
 
 void grpc_resolver_registry_shutdown(void) {
   int i;
   for (i = 0; i < g_number_of_resolvers; i++) {
-    gpr_free(g_all_of_the_resolvers[i].scheme);
-    grpc_resolver_factory_unref(g_all_of_the_resolvers[i].factory);
+    grpc_resolver_factory_unref(g_all_of_the_resolvers[i]);
   }
-  gpr_free(g_default_resolver_scheme);
+  gpr_free(g_default_resolver_prefix);
 }
 
-void grpc_register_resolver_type(const char *scheme,
-                                 grpc_resolver_factory *factory) {
+void grpc_register_resolver_type(grpc_resolver_factory *factory) {
   int i;
   for (i = 0; i < g_number_of_resolvers; i++) {
-    GPR_ASSERT(0 != strcmp(scheme, g_all_of_the_resolvers[i].scheme));
+    GPR_ASSERT(0 != strcmp(factory->vtable->scheme,
+                           g_all_of_the_resolvers[i]->vtable->scheme));
   }
   GPR_ASSERT(g_number_of_resolvers != MAX_RESOLVERS);
-  g_all_of_the_resolvers[g_number_of_resolvers].scheme = gpr_strdup(scheme);
   grpc_resolver_factory_ref(factory);
-  g_all_of_the_resolvers[g_number_of_resolvers].factory = factory;
-  g_number_of_resolvers++;
+  g_all_of_the_resolvers[g_number_of_resolvers++] = factory;
 }
 
 static grpc_resolver_factory *lookup_factory(grpc_uri *uri) {
@@ -85,40 +77,57 @@ static grpc_resolver_factory *lookup_factory(grpc_uri *uri) {
   if (!uri) return NULL;
 
   for (i = 0; i < g_number_of_resolvers; i++) {
-    if (0 == strcmp(uri->scheme, g_all_of_the_resolvers[i].scheme)) {
-      return g_all_of_the_resolvers[i].factory;
+    if (0 == strcmp(uri->scheme, g_all_of_the_resolvers[i]->vtable->scheme)) {
+      return g_all_of_the_resolvers[i];
     }
   }
 
   return NULL;
 }
 
-grpc_resolver *grpc_resolver_create(
-    const char *name, grpc_subchannel_factory *subchannel_factory) {
-  grpc_uri *uri;
+static grpc_resolver_factory *resolve_factory(const char *target,
+                                              grpc_uri **uri) {
   char *tmp;
   grpc_resolver_factory *factory = NULL;
-  grpc_resolver *resolver;
-
-  uri = grpc_uri_parse(name, 1);
-  factory = lookup_factory(uri);
-  if (factory == NULL && g_default_resolver_scheme != NULL) {
-    grpc_uri_destroy(uri);
-    gpr_asprintf(&tmp, "%s%s", g_default_resolver_scheme, name);
-    uri = grpc_uri_parse(tmp, 1);
-    factory = lookup_factory(uri);
-    if (factory == NULL) {
-      grpc_uri_destroy(grpc_uri_parse(name, 0));
-      grpc_uri_destroy(grpc_uri_parse(tmp, 0));
-      gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", name, tmp);
+
+  GPR_ASSERT(uri != NULL);
+  *uri = grpc_uri_parse(target, 1);
+  factory = lookup_factory(*uri);
+  if (factory == NULL) {
+    if (g_default_resolver_prefix != NULL) {
+      grpc_uri_destroy(*uri);
+      gpr_asprintf(&tmp, "%s%s", g_default_resolver_prefix, target);
+      *uri = grpc_uri_parse(tmp, 1);
+      factory = lookup_factory(*uri);
+      if (factory == NULL) {
+        grpc_uri_destroy(grpc_uri_parse(target, 0));
+        grpc_uri_destroy(grpc_uri_parse(tmp, 0));
+        gpr_log(GPR_ERROR, "don't know how to resolve '%s' or '%s'", target,
+                tmp);
+      }
+      gpr_free(tmp);
+    } else {
+      grpc_uri_destroy(grpc_uri_parse(target, 0));
+      gpr_log(GPR_ERROR, "don't know how to resolve '%s'", target);
     }
-    gpr_free(tmp);
-  } else if (factory == NULL) {
-    grpc_uri_destroy(grpc_uri_parse(name, 0));
-    gpr_log(GPR_ERROR, "don't know how to resolve '%s'", name);
   }
-  resolver =
+  return factory;
+}
+
+grpc_resolver *grpc_resolver_create(
+    const char *target, grpc_subchannel_factory *subchannel_factory) {
+  grpc_uri *uri = NULL;
+  grpc_resolver_factory *factory = resolve_factory(target, &uri);
+  grpc_resolver *resolver =
       grpc_resolver_factory_create_resolver(factory, uri, subchannel_factory);
   grpc_uri_destroy(uri);
   return resolver;
 }
+
+char *grpc_get_default_authority(const char *target) {
+  grpc_uri *uri = NULL;
+  grpc_resolver_factory *factory = resolve_factory(target, &uri);
+  char *authority = grpc_resolver_factory_get_default_authority(factory, uri);
+  grpc_uri_destroy(uri);
+  return authority;
+}
diff --git a/src/core/client_config/resolver_registry.h b/src/core/client_config/resolver_registry.h
index 31aa47620ab..5a7193b7ae2 100644
--- a/src/core/client_config/resolver_registry.h
+++ b/src/core/client_config/resolver_registry.h
@@ -44,19 +44,22 @@ void grpc_resolver_registry_shutdown(void);
     If \a priority is greater than zero, then the resolver will be eligible
     to resolve names that are passed in with no scheme. Higher priority
     resolvers will be tried before lower priority schemes. */
-void grpc_register_resolver_type(const char *scheme,
-                                 grpc_resolver_factory *factory);
+void grpc_register_resolver_type(grpc_resolver_factory *factory);
 
-/** Create a resolver given \a name.
-    First tries to parse \a name as a URI. If this succeeds, tries
+/** Create a resolver given \a target.
+    First tries to parse \a target as a URI. If this succeeds, tries
     to locate a registered resolver factory based on the URI scheme.
     If parsing or location fails, prefixes default_prefix from
-    grpc_resolver_registry_init to name, and tries again (if default_prefix
+    grpc_resolver_registry_init to target, and tries again (if default_prefix
     was not NULL).
     If a resolver factory was found, use it to instantiate a resolver and
     return it.
     If a resolver factory was not found, return NULL. */
 grpc_resolver *grpc_resolver_create(
-    const char *name, grpc_subchannel_factory *subchannel_factory);
+    const char *target, grpc_subchannel_factory *subchannel_factory);
+
+/** Given a target, return a (freshly allocated with gpr_malloc) string
+    representing the default authority to pass from a client. */
+char *grpc_get_default_authority(const char *target);
 
 #endif /* GRPC_INTERNAL_CORE_CLIENT_CONFIG_RESOLVER_REGISTRY_H */
diff --git a/src/core/client_config/resolvers/dns_resolver.c b/src/core/client_config/resolvers/dns_resolver.c
index 7b35b7902f7..84643c464a9 100644
--- a/src/core/client_config/resolvers/dns_resolver.c
+++ b/src/core/client_config/resolvers/dns_resolver.c
@@ -203,9 +203,6 @@ static grpc_resolver *dns_create(
     grpc_subchannel_factory *subchannel_factory) {
   dns_resolver *r;
   const char *path = uri->path;
-  grpc_arg default_host_arg;
-  char *host;
-  char *port;
 
   if (0 != strcmp(uri->authority, "")) {
     gpr_log(GPR_ERROR, "authority based uri's not supported");
@@ -214,17 +211,6 @@ static grpc_resolver *dns_create(
 
   if (path[0] == '/') ++path;
 
-  gpr_split_host_port(path, &host, &port);
-
-  default_host_arg.type = GRPC_ARG_STRING;
-  default_host_arg.key = GRPC_ARG_DEFAULT_AUTHORITY;
-  default_host_arg.value.string = host;
-  subchannel_factory = grpc_subchannel_factory_add_channel_arg(
-      subchannel_factory, &default_host_arg);
-
-  gpr_free(host);
-  gpr_free(port);
-
   r = gpr_malloc(sizeof(dns_resolver));
   memset(r, 0, sizeof(*r));
   gpr_ref_init(&r->refs, 1);
@@ -233,6 +219,7 @@ static grpc_resolver *dns_create(
   r->name = gpr_strdup(path);
   r->default_port = gpr_strdup(default_port);
   r->subchannel_factory = subchannel_factory;
+  grpc_subchannel_factory_ref(subchannel_factory);
   r->lb_policy_factory = lb_policy_factory;
   return &r->base;
 }
@@ -252,8 +239,16 @@ static grpc_resolver *dns_factory_create_resolver(
                     subchannel_factory);
 }
 
+char *dns_factory_get_default_host_name(grpc_resolver_factory *factory,
+                                        grpc_uri *uri) {
+  const char *path = uri->path;
+  if (path[0] == '/') ++path;
+  return gpr_strdup(path);
+}
+
 static const grpc_resolver_factory_vtable dns_factory_vtable = {
-    dns_factory_ref, dns_factory_unref, dns_factory_create_resolver};
+    dns_factory_ref, dns_factory_unref, dns_factory_create_resolver,
+    dns_factory_get_default_host_name, "dns"};
 static grpc_resolver_factory dns_resolver_factory = {&dns_factory_vtable};
 
 grpc_resolver_factory *grpc_dns_resolver_factory_create() {
diff --git a/src/core/client_config/resolvers/sockaddr_resolver.c b/src/core/client_config/resolvers/sockaddr_resolver.c
index 84198739081..0d8540a5665 100644
--- a/src/core/client_config/resolvers/sockaddr_resolver.c
+++ b/src/core/client_config/resolvers/sockaddr_resolver.c
@@ -166,8 +166,29 @@ static int parse_unix(grpc_uri *uri, struct sockaddr_storage *addr, int *len) {
 
   return 1;
 }
+
+static char *unix_get_default_authority(grpc_resolver_factory *factory,
+                                        grpc_uri *uri) {
+  return gpr_strdup("localhost");
+}
 #endif
 
+static char *ip_get_default_authority(grpc_uri *uri) {
+  const char *path = uri->path;
+  if (path[0] == '/') ++path;
+  return gpr_strdup(path);
+}
+
+static char *ipv4_get_default_authority(grpc_resolver_factory *factory,
+                                        grpc_uri *uri) {
+  return ip_get_default_authority(uri);
+}
+
+static char *ipv6_get_default_authority(grpc_resolver_factory *factory,
+                                        grpc_uri *uri) {
+  return ip_get_default_authority(uri);
+}
+
 static int parse_ipv4(grpc_uri *uri, struct sockaddr_storage *addr, int *len) {
   const char *host_port = uri->path;
   char *host;
@@ -313,20 +334,20 @@ static void sockaddr_factory_ref(grpc_resolver_factory *factory) {}
 
 static void sockaddr_factory_unref(grpc_resolver_factory *factory) {}
 
-#define DECL_FACTORY(name)                                            \
-  static grpc_resolver *name##_factory_create_resolver(               \
-      grpc_resolver_factory *factory, grpc_uri *uri,                  \
-      grpc_subchannel_factory *subchannel_factory) {                  \
-    return sockaddr_create(uri, grpc_create_pick_first_lb_policy,     \
-                           subchannel_factory, parse_##name);         \
-  }                                                                   \
-  static const grpc_resolver_factory_vtable name##_factory_vtable = { \
-      sockaddr_factory_ref, sockaddr_factory_unref,                   \
-      name##_factory_create_resolver};                                \
-  static grpc_resolver_factory name##_resolver_factory = {            \
-      &name##_factory_vtable};                                        \
-  grpc_resolver_factory *grpc_##name##_resolver_factory_create() {    \
-    return &name##_resolver_factory;                                  \
+#define DECL_FACTORY(name)                                                  \
+  static grpc_resolver *name##_factory_create_resolver(                     \
+      grpc_resolver_factory *factory, grpc_uri *uri,                        \
+      grpc_subchannel_factory *subchannel_factory) {                        \
+    return sockaddr_create(uri, grpc_create_pick_first_lb_policy,           \
+                           subchannel_factory, parse_##name);               \
+  }                                                                         \
+  static const grpc_resolver_factory_vtable name##_factory_vtable = {       \
+      sockaddr_factory_ref, sockaddr_factory_unref,                         \
+      name##_factory_create_resolver, name##_get_default_authority, #name}; \
+  static grpc_resolver_factory name##_resolver_factory = {                  \
+      &name##_factory_vtable};                                              \
+  grpc_resolver_factory *grpc_##name##_resolver_factory_create() {          \
+    return &name##_resolver_factory;                                        \
   }
 
 #ifdef GPR_POSIX_SOCKET
diff --git a/src/core/client_config/resolvers/zookeeper_resolver.c b/src/core/client_config/resolvers/zookeeper_resolver.c
index acb2ba136e9..da399f99548 100644
--- a/src/core/client_config/resolvers/zookeeper_resolver.c
+++ b/src/core/client_config/resolvers/zookeeper_resolver.c
@@ -467,8 +467,7 @@ static grpc_resolver *zookeeper_create(
 }
 
 static void zookeeper_plugin_init() {
-  grpc_register_resolver_type("zookeeper",
-                              grpc_zookeeper_resolver_factory_create());
+  grpc_register_resolver_type(grpc_zookeeper_resolver_factory_create());
 }
 
 void grpc_zookeeper_register() {
@@ -483,6 +482,11 @@ static void zookeeper_factory_ref(grpc_resolver_factory *factory) {}
 
 static void zookeeper_factory_unref(grpc_resolver_factory *factory) {}
 
+static char *zookeeper_factory_get_default_hostname(
+    grpc_resolver_factory *factory, grpc_uri *uri) {
+  return NULL;
+}
+
 static grpc_resolver *zookeeper_factory_create_resolver(
     grpc_resolver_factory *factory, grpc_uri *uri,
     grpc_subchannel_factory *subchannel_factory) {
@@ -492,7 +496,8 @@ static grpc_resolver *zookeeper_factory_create_resolver(
 
 static const grpc_resolver_factory_vtable zookeeper_factory_vtable = {
     zookeeper_factory_ref, zookeeper_factory_unref,
-    zookeeper_factory_create_resolver};
+    zookeeper_factory_create_resolver, zookeeper_factory_get_default_hostname,
+    "zookeeper"};
 static grpc_resolver_factory zookeeper_resolver_factory = {
     &zookeeper_factory_vtable};
 
diff --git a/src/core/profiling/basic_timers.c b/src/core/profiling/basic_timers.c
index ae37f584ebb..4b6a0d2f56b 100644
--- a/src/core/profiling/basic_timers.c
+++ b/src/core/profiling/basic_timers.c
@@ -36,7 +36,6 @@
 #ifdef GRPC_BASIC_PROFILER
 
 #include "src/core/profiling/timers.h"
-#include "src/core/profiling/timers_preciseclock.h"
 
 #include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
@@ -53,7 +52,7 @@ typedef enum {
 } marker_type;
 
 typedef struct grpc_timer_entry {
-  grpc_precise_clock tm;
+  gpr_timespec tm;
   int tag;
   const char* tagstr;
   marker_type type;
@@ -71,9 +70,8 @@ static void log_report() {
   int i;
   for (i = 0; i < count; i++) {
     grpc_timer_entry* entry = &(log[i]);
-    printf("GRPC_LAT_PROF " GRPC_PRECISE_CLOCK_FORMAT
-           " %p %c %d(%s) %p %s %d\n",
-           GRPC_PRECISE_CLOCK_PRINTF_ARGS(&entry->tm),
+    printf("GRPC_LAT_PROF %ld.%09d  %p %c %d(%s) %p %s %d\n",
+           entry->tm.tv_sec, entry->tm.tv_nsec,
            (void*)(gpr_intptr)gpr_thd_currentid(), entry->type, entry->tag,
            entry->tagstr, entry->id, entry->file, entry->line);
   }
@@ -93,7 +91,7 @@ static void grpc_timers_log_add(int tag, const char* tagstr, marker_type type,
 
   entry = &log[count++];
 
-  grpc_precise_clock_now(&entry->tm);
+  entry->tm = gpr_now(GPR_CLOCK_PRECISE);
   entry->tag = tag;
   entry->tagstr = tagstr;
   entry->type = type;
diff --git a/src/core/support/time_posix.c b/src/core/support/time_posix.c
index 841485c4b4a..a2744002437 100644
--- a/src/core/support/time_posix.c
+++ b/src/core/support/time_posix.c
@@ -32,6 +32,7 @@
  */
 
 #include <grpc/support/port_platform.h>
+#include <src/core/support/time_precise.h>
 
 #ifdef GPR_POSIX_TIME
 
@@ -66,8 +67,14 @@ void gpr_time_init(void) {}
 gpr_timespec gpr_now(gpr_clock_type clock) {
   struct timespec now;
   GPR_ASSERT(clock != GPR_TIMESPAN);
-  clock_gettime(clockid_for_gpr_clock[clock], &now);
-  return gpr_from_timespec(now, clock);
+  if (clock == GPR_CLOCK_PRECISE) {
+    gpr_timespec ret;
+    gpr_precise_clock_now(&ret);
+    return ret;
+  } else {
+    clock_gettime(clockid_for_gpr_clock[clock], &now);
+    return gpr_from_timespec(now, clock);
+  }
 }
 #else
 /* For some reason Apple's OSes haven't implemented clock_gettime. */
@@ -104,6 +111,9 @@ gpr_timespec gpr_now(gpr_clock_type clock) {
       now.tv_sec = now_dbl * 1e-9;
       now.tv_nsec = now_dbl - now.tv_sec * 1e9;
       break;
+    case GPR_CLOCK_PRECISE:
+      gpr_precise_clock_now(&now);
+      break;
     case GPR_TIMESPAN:
       abort();
   }
diff --git a/src/core/profiling/timers_preciseclock.h b/src/core/support/time_precise.h
similarity index 65%
rename from src/core/profiling/timers_preciseclock.h
rename to src/core/support/time_precise.h
index 5c251b47e6f..574ebb84489 100644
--- a/src/core/profiling/timers_preciseclock.h
+++ b/src/core/support/time_precise.h
@@ -31,65 +31,63 @@
  *
  */
 
-#ifndef GRPC_CORE_PROFILING_TIMERS_PRECISECLOCK_H
-#define GRPC_CORE_PROFILING_TIMERS_PRECISECLOCK_H
+#ifndef GRPC_CORE_SUPPORT_TIME_PRECISE_H_
+#define GRPC_CORE_SUPPORT_TIME_PRECISE_H_
 
 #include <grpc/support/sync.h>
 #include <grpc/support/time.h>
 #include <stdio.h>
 
 #ifdef GRPC_TIMERS_RDTSC
-typedef long long int grpc_precise_clock;
 #if defined(__i386__)
-static void grpc_precise_clock_now(grpc_precise_clock *clk) {
-  grpc_precise_clock ret;
+static void gpr_get_cycle_counter(long long int *clk) {
+  long long int ret;
   __asm__ volatile("rdtsc" : "=A"(ret));
   *clk = ret;
 }
 
 // ----------------------------------------------------------------
 #elif defined(__x86_64__) || defined(__amd64__)
-static void grpc_precise_clock_now(grpc_precise_clock *clk) {
+static void gpr_get_cycle_counter(long long int *clk) {
   unsigned long long low, high;
   __asm__ volatile("rdtsc" : "=a"(low), "=d"(high));
   *clk = (high << 32) | low;
 }
 #endif
+
 static gpr_once precise_clock_init = GPR_ONCE_INIT;
-static double cycles_per_second = 0.0;
-static void grpc_precise_clock_init() {
+static long long cycles_per_second = 0;
+static void gpr_precise_clock_init() {
   time_t start = time(NULL);
-  grpc_precise_clock start_time;
-  grpc_precise_clock end_time;
+  gpr_precise_clock start_cycle;
+  gpr_precise_clock end_cycle;
   while (time(NULL) == start)
     ;
-  grpc_precise_clock_now(&start_time);
+  gpr_get_cycle_counter(&start_cycle);
   while (time(NULL) == start + 1)
     ;
-  grpc_precise_clock_now(&end_time);
-  cycles_per_second = end_time - start_time;
+  gpr_get_cycle_counter(&end_cycle);
+  cycles_per_second = end_cycle - start_cycle;
 }
+
 static double grpc_precise_clock_scaling_factor() {
   gpr_once_init(&precise_clock_init, grpc_precise_clock_init);
   return 1e6 / cycles_per_second;
 }
-#define GRPC_PRECISE_CLOCK_FORMAT "%f"
-#define GRPC_PRECISE_CLOCK_PRINTF_ARGS(clk) \
-  (*(clk)*grpc_precise_clock_scaling_factor())
-#else
-typedef struct grpc_precise_clock grpc_precise_clock;
-struct grpc_precise_clock {
-  gpr_timespec clock;
-};
-static void grpc_precise_clock_now(grpc_precise_clock* clk) {
-  clk->clock = gpr_now(GPR_CLOCK_REALTIME);
+
+static void gpr_precise_clock_now(gpr_timespec *clk) {
+  long long int counter;
+  gpr_get_cycle_counter(&counter);
+  clk->clock = GPR_CLOCK_REALTIME;
+  clk->tv_sec = counter / cycles_per_second;
+  clk->tv_nsec = counter % cycles_per_second;
 }
-#define GRPC_PRECISE_CLOCK_FORMAT "%ld.%09d"
-#define GRPC_PRECISE_CLOCK_PRINTF_ARGS(clk) \
-  (clk)->clock.tv_sec, (clk)->clock.tv_nsec
-static void grpc_precise_clock_print(const grpc_precise_clock* clk, FILE* fp) {
-  fprintf(fp, "%ld.%09d", clk->clock.tv_sec, clk->clock.tv_nsec);
+
+#else /* GRPC_TIMERS_RDTSC */
+static void gpr_precise_clock_now(gpr_timespec *clk) {
+  *clk = gpr_now(GPR_CLOCK_REALTIME);
+  clk->clock_type = GPR_CLOCK_PRECISE;
 }
 #endif /* GRPC_TIMERS_RDTSC */
 
-#endif /* GRPC_CORE_PROFILING_TIMERS_PRECISECLOCK_H */
+#endif /* GRPC_CORE_SUPPORT_TIME_PRECISE_ */
diff --git a/src/core/support/time_win32.c b/src/core/support/time_win32.c
index 7f64c80e276..f794855429b 100644
--- a/src/core/support/time_win32.c
+++ b/src/core/support/time_win32.c
@@ -38,6 +38,7 @@
 #ifdef GPR_WIN32
 
 #include <grpc/support/time.h>
+#include <src/core/support/time_precise.h>
 #include <sys/timeb.h>
 
 static LARGE_INTEGER g_start_time;
@@ -68,6 +69,9 @@ gpr_timespec gpr_now(gpr_clock_type clock) {
       now_tv.tv_sec = (time_t)now_dbl;
       now_tv.tv_nsec = (int)((now_dbl - (double)now_tv.tv_sec) * 1e9);
       break;
+    case GPR_CLOCK_PRECISE:
+      gpr_precise_clock_now(&now_tv);
+      break;
   }
   return now_tv;
 }
diff --git a/src/core/surface/channel.c b/src/core/surface/channel.c
index e50251566d5..586402e21c3 100644
--- a/src/core/surface/channel.c
+++ b/src/core/surface/channel.c
@@ -40,6 +40,7 @@
 #include <grpc/support/log.h>
 #include <grpc/support/string_util.h>
 
+#include "src/core/client_config/resolver_registry.h"
 #include "src/core/iomgr/iomgr.h"
 #include "src/core/support/string.h"
 #include "src/core/surface/call.h"
@@ -70,6 +71,7 @@ struct grpc_channel {
   grpc_mdstr *grpc_message_string;
   grpc_mdstr *path_string;
   grpc_mdstr *authority_string;
+  grpc_mdelem *default_authority;
   /** mdelem for grpc-status: 0 thru grpc-status: 2 */
   grpc_mdelem *grpc_status_elem[NUM_CACHED_STATUS_ELEMS];
 
@@ -134,10 +136,47 @@ grpc_channel *grpc_channel_create_from_filters(
         } else {
           channel->max_message_length = args->args[i].value.integer;
         }
+      } else if (0 == strcmp(args->args[i].key, GRPC_ARG_DEFAULT_AUTHORITY)) {
+        if (args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s: must be an string",
+                  GRPC_ARG_DEFAULT_AUTHORITY);
+        } else {
+          if (channel->default_authority) {
+            /* setting this takes precedence over anything else */
+            GRPC_MDELEM_UNREF(channel->default_authority);
+          }
+          channel->default_authority = grpc_mdelem_from_strings(
+              mdctx, ":authority", args->args[i].value.string);
+        }
+      } else if (0 ==
+                 strcmp(args->args[i].key, GRPC_SSL_TARGET_NAME_OVERRIDE_ARG)) {
+        if (args->args[i].type != GRPC_ARG_STRING) {
+          gpr_log(GPR_ERROR, "%s: must be an string",
+                  GRPC_SSL_TARGET_NAME_OVERRIDE_ARG);
+        } else {
+          if (channel->default_authority) {
+            /* other ways of setting this (notably ssl) take precedence */
+            gpr_log(GPR_ERROR, "%s: default host already set some other way",
+                    GRPC_ARG_DEFAULT_AUTHORITY);
+          } else {
+            channel->default_authority = grpc_mdelem_from_strings(
+                mdctx, ":authority", args->args[i].value.string);
+          }
+        }
       }
     }
   }
 
+  if (channel->is_client && channel->default_authority == NULL &&
+      target != NULL) {
+    char *default_authority = grpc_get_default_authority(target);
+    if (default_authority) {
+      channel->default_authority = grpc_mdelem_from_strings(
+          channel->metadata_context, ":authority", default_authority);
+    }
+    gpr_free(default_authority);
+  }
+
   grpc_channel_stack_init(filters, num_filters, channel, args,
                           channel->metadata_context,
                           CHANNEL_STACK_FROM_CHANNEL(channel));
@@ -161,6 +200,8 @@ static grpc_call *grpc_channel_create_call_internal(
   send_metadata[num_metadata++] = path_mdelem;
   if (authority_mdelem != NULL) {
     send_metadata[num_metadata++] = authority_mdelem;
+  } else if (channel->default_authority != NULL) {
+    send_metadata[num_metadata++] = GRPC_MDELEM_REF(channel->default_authority);
   }
 
   return grpc_call_create(channel, parent_call, propagation_mask, cq, NULL,
@@ -251,6 +292,9 @@ static void destroy_channel(void *p, int ok) {
     }
     gpr_free(rc);
   }
+  if (channel->default_authority != NULL) {
+    GRPC_MDELEM_UNREF(channel->default_authority);
+  }
   grpc_mdctx_unref(channel->metadata_context);
   gpr_mu_destroy(&channel->registered_call_mu);
   gpr_free(channel->target);
diff --git a/src/core/surface/init.c b/src/core/surface/init.c
index d9044549f21..0d48cd42d72 100644
--- a/src/core/surface/init.c
+++ b/src/core/surface/init.c
@@ -86,11 +86,11 @@ void grpc_init(void) {
   if (++g_initializations == 1) {
     gpr_time_init();
     grpc_resolver_registry_init("dns:///");
-    grpc_register_resolver_type("dns", grpc_dns_resolver_factory_create());
-    grpc_register_resolver_type("ipv4", grpc_ipv4_resolver_factory_create());
-    grpc_register_resolver_type("ipv6", grpc_ipv6_resolver_factory_create());
+    grpc_register_resolver_type(grpc_dns_resolver_factory_create());
+    grpc_register_resolver_type(grpc_ipv4_resolver_factory_create());
+    grpc_register_resolver_type(grpc_ipv6_resolver_factory_create());
 #ifdef GPR_POSIX_SOCKET
-    grpc_register_resolver_type("unix", grpc_unix_resolver_factory_create());
+    grpc_register_resolver_type(grpc_unix_resolver_factory_create());
 #endif
     grpc_register_tracer("channel", &grpc_trace_channel);
     grpc_register_tracer("surface", &grpc_surface_trace);
diff --git a/src/cpp/common/call.cc b/src/cpp/common/call.cc
index 16aa2c9fb9d..5b87c2a8067 100644
--- a/src/cpp/common/call.cc
+++ b/src/cpp/common/call.cc
@@ -41,13 +41,14 @@
 
 namespace grpc {
 
-void FillMetadataMap(grpc_metadata_array* arr,
-                     std::multimap<grpc::string, grpc::string>* metadata) {
+void FillMetadataMap(
+    grpc_metadata_array* arr,
+    std::multimap<grpc::string_ref, grpc::string_ref>* metadata) {
   for (size_t i = 0; i < arr->count; i++) {
     // TODO(yangg) handle duplicates?
-    metadata->insert(std::pair<grpc::string, grpc::string>(
-        arr->metadata[i].key,
-        grpc::string(arr->metadata[i].value, arr->metadata[i].value_length)));
+    metadata->insert(std::pair<grpc::string_ref, grpc::string_ref>(
+        arr->metadata[i].key, grpc::string_ref(arr->metadata[i].value,
+                                               arr->metadata[i].value_length)));
   }
   grpc_metadata_array_destroy(arr);
   grpc_metadata_array_init(arr);
diff --git a/src/cpp/server/server.cc b/src/cpp/server/server.cc
index 66cd27cc339..bb83c7d887b 100644
--- a/src/cpp/server/server.cc
+++ b/src/cpp/server/server.cc
@@ -439,11 +439,12 @@ Server::BaseAsyncRequest::~BaseAsyncRequest() {}
 bool Server::BaseAsyncRequest::FinalizeResult(void** tag, bool* status) {
   if (*status) {
     for (size_t i = 0; i < initial_metadata_array_.count; i++) {
-      context_->client_metadata_.insert(std::make_pair(
-          grpc::string(initial_metadata_array_.metadata[i].key),
-          grpc::string(initial_metadata_array_.metadata[i].value,
-                       initial_metadata_array_.metadata[i].value +
-                           initial_metadata_array_.metadata[i].value_length)));
+      context_->client_metadata_.insert(
+          std::pair<grpc::string_ref, grpc::string_ref>(
+              initial_metadata_array_.metadata[i].key,
+              grpc::string_ref(
+                  initial_metadata_array_.metadata[i].value,
+                  initial_metadata_array_.metadata[i].value_length)));
     }
   }
   grpc_metadata_array_destroy(&initial_metadata_array_);
diff --git a/src/cpp/server/server_context.cc b/src/cpp/server/server_context.cc
index acc163d6b5d..8193e70660d 100644
--- a/src/cpp/server/server_context.cc
+++ b/src/cpp/server/server_context.cc
@@ -136,10 +136,9 @@ ServerContext::ServerContext(gpr_timespec deadline, grpc_metadata* metadata,
       cq_(nullptr),
       sent_initial_metadata_(false) {
   for (size_t i = 0; i < metadata_count; i++) {
-    client_metadata_.insert(std::make_pair(
-        grpc::string(metadata[i].key),
-        grpc::string(metadata[i].value,
-                     metadata[i].value + metadata[i].value_length)));
+    client_metadata_.insert(std::pair<grpc::string_ref, grpc::string_ref>(
+        metadata[i].key,
+        grpc::string_ref(metadata[i].value, metadata[i].value_length)));
   }
 }
 
diff --git a/src/cpp/util/string_ref.cc b/src/cpp/util/string_ref.cc
index 8483e8c2eea..eb54f65e3ac 100644
--- a/src/cpp/util/string_ref.cc
+++ b/src/cpp/util/string_ref.cc
@@ -39,7 +39,7 @@
 
 namespace grpc {
 
-constexpr size_t string_ref::npos;
+const size_t string_ref::npos;
 
 string_ref& string_ref::operator=(const string_ref& rhs) {
   data_ = rhs.data_;
@@ -108,4 +108,8 @@ bool operator>=(string_ref x, string_ref y) {
   return x.compare(y) >= 0;
 }
 
+std::ostream& operator<<(std::ostream& out, const string_ref& string) {
+  return out << grpc::string(string.begin(), string.end());
+}
+
 }  // namespace grpc
diff --git a/templates/Makefile.template b/templates/Makefile.template
index 00582a22f8d..797f0ab57fa 100644
--- a/templates/Makefile.template
+++ b/templates/Makefile.template
@@ -859,8 +859,8 @@ else
 	$(Q)(cd third_party/openssl ; CC="$(CC) $(PIC_CPPFLAGS) -fvisibility=hidden $(CPPFLAGS_$(CONFIG)) $(OPENSSL_CFLAGS_$(CONFIG)) $(OPENSSL_CFLAGS_EXTRA)" ./config no-asm $(OPENSSL_CONFIG_$(CONFIG)))
 endif
 endif
-	$(Q)$(MAKE) -C third_party/openssl clean
-	$(Q)(unset CPPFLAGS; $(MAKE) -C third_party/openssl build_crypto build_ssl)
+	$(Q)$(MAKE) -j 1 -C third_party/openssl clean
+	$(Q)(unset CPPFLAGS; $(MAKE) -j 1 -C third_party/openssl build_crypto build_ssl)
 	$(Q)mkdir -p $(LIBDIR)/$(CONFIG)/openssl
 	$(Q)cp third_party/openssl/libssl.a third_party/openssl/libcrypto.a $(LIBDIR)/$(CONFIG)/openssl
 
diff --git a/test/core/end2end/tests/default_host.c b/test/core/end2end/tests/default_host.c
index 97c19db331d..57f65b834b0 100644
--- a/test/core/end2end/tests/default_host.c
+++ b/test/core/end2end/tests/default_host.c
@@ -201,7 +201,7 @@ static void simple_request_body(grpc_end2end_test_fixture f) {
   GPR_ASSERT(status == GRPC_STATUS_UNIMPLEMENTED);
   GPR_ASSERT(0 == strcmp(details, "xyz"));
   GPR_ASSERT(0 == strcmp(call_details.method, "/foo"));
-  GPR_ASSERT(0 == strcmp(call_details.host, "localhost"));
+  GPR_ASSERT(0 == strncmp(call_details.host, "localhost", 9));
   GPR_ASSERT(was_cancelled == 1);
 
   gpr_free(details);
diff --git a/test/core/iomgr/tcp_client_posix_test.c b/test/core/iomgr/tcp_client_posix_test.c
index dea0b33b8e9..f0e2de24d95 100644
--- a/test/core/iomgr/tcp_client_posix_test.c
+++ b/test/core/iomgr/tcp_client_posix_test.c
@@ -39,10 +39,12 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
-#include "src/core/iomgr/iomgr.h"
-#include "src/core/iomgr/socket_utils_posix.h"
+#include <grpc/grpc.h>
 #include <grpc/support/log.h>
 #include <grpc/support/time.h>
+
+#include "src/core/iomgr/iomgr.h"
+#include "src/core/iomgr/socket_utils_posix.h"
 #include "test/core/util/test_config.h"
 
 static grpc_pollset_set g_pollset_set;
@@ -198,16 +200,21 @@ void test_times_out(void) {
 
   /* Make sure the event doesn't trigger early */
   gpr_mu_lock(GRPC_POLLSET_MU(&g_pollset));
-  while (gpr_time_cmp(gpr_time_add(connect_deadline,
-                                   gpr_time_from_seconds(2, GPR_TIMESPAN)),
-                      gpr_now(connect_deadline.clock_type)) > 0) {
-    int is_after_deadline =
-        gpr_time_cmp(connect_deadline, gpr_now(GPR_CLOCK_MONOTONIC)) <= 0;
+  for (;;) {
     grpc_pollset_worker worker;
+    gpr_timespec now = gpr_now(connect_deadline.clock_type);
+    gpr_timespec continue_verifying_time = gpr_time_from_seconds(2, GPR_TIMESPAN);
+    gpr_timespec grace_time = gpr_time_from_seconds(1, GPR_TIMESPAN);
+    gpr_timespec finish_time = gpr_time_add(connect_deadline, continue_verifying_time);
+    gpr_timespec restart_verifying_time = gpr_time_add(connect_deadline, grace_time);
+    int is_after_deadline = gpr_time_cmp(now, connect_deadline) > 0;
+    if (gpr_time_cmp(now, finish_time) > 0) {
+      break;
+    }
+    gpr_log(GPR_DEBUG, "now=%d.%09d connect_deadline=%d.%09d", 
+        now.tv_sec, now.tv_nsec, connect_deadline.tv_sec, connect_deadline.tv_nsec);
     if (is_after_deadline &&
-        gpr_time_cmp(gpr_time_add(connect_deadline,
-                                  gpr_time_from_seconds(1, GPR_TIMESPAN)),
-                     gpr_now(GPR_CLOCK_MONOTONIC)) > 0) {
+        gpr_time_cmp(now, restart_verifying_time) <= 0) {
       /* allow some slack before insisting that things be done */
     } else {
       GPR_ASSERT(g_connections_complete ==
@@ -228,7 +235,7 @@ static void destroy_pollset(void *p) { grpc_pollset_destroy(p); }
 
 int main(int argc, char **argv) {
   grpc_test_init(argc, argv);
-  grpc_iomgr_init();
+  grpc_init();
   grpc_pollset_set_init(&g_pollset_set);
   grpc_pollset_init(&g_pollset);
   grpc_pollset_set_add_pollset(&g_pollset_set, &g_pollset);
@@ -238,6 +245,6 @@ int main(int argc, char **argv) {
   test_times_out();
   grpc_pollset_set_destroy(&g_pollset_set);
   grpc_pollset_shutdown(&g_pollset, destroy_pollset, &g_pollset);
-  grpc_iomgr_shutdown();
+  grpc_shutdown();
   return 0;
 }
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 6343810ee93..41b91e459bc 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -50,6 +50,7 @@
 #include "test/core/util/test_config.h"
 #include "test/cpp/util/echo_duplicate.grpc.pb.h"
 #include "test/cpp/util/echo.grpc.pb.h"
+#include "test/cpp/util/string_ref_helper.h"
 
 #ifdef GPR_POSIX_SOCKET
 #include "src/core/iomgr/pollset_posix.h"
@@ -484,8 +485,10 @@ TEST_P(AsyncEnd2endTest, ClientInitialMetadataRpc) {
   Verifier(GetParam()).Expect(2, true).Verify(cq_.get());
   EXPECT_EQ(send_request.message(), recv_request.message());
   auto client_initial_metadata = srv_ctx.client_metadata();
-  EXPECT_EQ(meta1.second, client_initial_metadata.find(meta1.first)->second);
-  EXPECT_EQ(meta2.second, client_initial_metadata.find(meta2.first)->second);
+  EXPECT_EQ(meta1.second,
+            ToString(client_initial_metadata.find(meta1.first)->second));
+  EXPECT_EQ(meta2.second,
+            ToString(client_initial_metadata.find(meta2.first)->second));
   EXPECT_GE(client_initial_metadata.size(), static_cast<size_t>(2));
 
   send_response.set_message(recv_request.message());
@@ -532,8 +535,10 @@ TEST_P(AsyncEnd2endTest, ServerInitialMetadataRpc) {
   response_reader->ReadInitialMetadata(tag(4));
   Verifier(GetParam()).Expect(4, true).Verify(cq_.get());
   auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
-  EXPECT_EQ(meta1.second, server_initial_metadata.find(meta1.first)->second);
-  EXPECT_EQ(meta2.second, server_initial_metadata.find(meta2.first)->second);
+  EXPECT_EQ(meta1.second,
+            ToString(server_initial_metadata.find(meta1.first)->second));
+  EXPECT_EQ(meta2.second,
+            ToString(server_initial_metadata.find(meta2.first)->second));
   EXPECT_EQ(static_cast<size_t>(2), server_initial_metadata.size());
 
   send_response.set_message(recv_request.message());
@@ -586,8 +591,10 @@ TEST_P(AsyncEnd2endTest, ServerTrailingMetadataRpc) {
   EXPECT_EQ(send_response.message(), recv_response.message());
   EXPECT_TRUE(recv_status.ok());
   auto server_trailing_metadata = cli_ctx.GetServerTrailingMetadata();
-  EXPECT_EQ(meta1.second, server_trailing_metadata.find(meta1.first)->second);
-  EXPECT_EQ(meta2.second, server_trailing_metadata.find(meta2.first)->second);
+  EXPECT_EQ(meta1.second,
+            ToString(server_trailing_metadata.find(meta1.first)->second));
+  EXPECT_EQ(meta2.second,
+            ToString(server_trailing_metadata.find(meta2.first)->second));
   EXPECT_EQ(static_cast<size_t>(2), server_trailing_metadata.size());
 }
 
@@ -631,8 +638,10 @@ TEST_P(AsyncEnd2endTest, MetadataRpc) {
   Verifier(GetParam()).Expect(2, true).Verify(cq_.get());
   EXPECT_EQ(send_request.message(), recv_request.message());
   auto client_initial_metadata = srv_ctx.client_metadata();
-  EXPECT_EQ(meta1.second, client_initial_metadata.find(meta1.first)->second);
-  EXPECT_EQ(meta2.second, client_initial_metadata.find(meta2.first)->second);
+  EXPECT_EQ(meta1.second,
+            ToString(client_initial_metadata.find(meta1.first)->second));
+  EXPECT_EQ(meta2.second,
+            ToString(client_initial_metadata.find(meta2.first)->second));
   EXPECT_GE(client_initial_metadata.size(), static_cast<size_t>(2));
 
   srv_ctx.AddInitialMetadata(meta3.first, meta3.second);
@@ -642,8 +651,10 @@ TEST_P(AsyncEnd2endTest, MetadataRpc) {
   response_reader->ReadInitialMetadata(tag(4));
   Verifier(GetParam()).Expect(4, true).Verify(cq_.get());
   auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
-  EXPECT_EQ(meta3.second, server_initial_metadata.find(meta3.first)->second);
-  EXPECT_EQ(meta4.second, server_initial_metadata.find(meta4.first)->second);
+  EXPECT_EQ(meta3.second,
+            ToString(server_initial_metadata.find(meta3.first)->second));
+  EXPECT_EQ(meta4.second,
+            ToString(server_initial_metadata.find(meta4.first)->second));
   EXPECT_GE(server_initial_metadata.size(), static_cast<size_t>(2));
 
   send_response.set_message(recv_request.message());
@@ -658,8 +669,10 @@ TEST_P(AsyncEnd2endTest, MetadataRpc) {
   EXPECT_EQ(send_response.message(), recv_response.message());
   EXPECT_TRUE(recv_status.ok());
   auto server_trailing_metadata = cli_ctx.GetServerTrailingMetadata();
-  EXPECT_EQ(meta5.second, server_trailing_metadata.find(meta5.first)->second);
-  EXPECT_EQ(meta6.second, server_trailing_metadata.find(meta6.first)->second);
+  EXPECT_EQ(meta5.second,
+            ToString(server_trailing_metadata.find(meta5.first)->second));
+  EXPECT_EQ(meta6.second,
+            ToString(server_trailing_metadata.find(meta6.first)->second));
   EXPECT_GE(server_trailing_metadata.size(), static_cast<size_t>(2));
 }
 
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index 2728dce07e5..0d5bf36df72 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -53,6 +53,7 @@
 #include "test/core/util/test_config.h"
 #include "test/cpp/util/echo_duplicate.grpc.pb.h"
 #include "test/cpp/util/echo.grpc.pb.h"
+#include "test/cpp/util/string_ref_helper.h"
 
 using grpc::cpp::test::util::EchoRequest;
 using grpc::cpp::test::util::EchoResponse;
@@ -152,12 +153,13 @@ class TestServiceImpl : public ::grpc::cpp::test::util::TestService::Service {
     }
 
     if (request->has_param() && request->param().echo_metadata()) {
-      const std::multimap<grpc::string, grpc::string>& client_metadata =
+      const std::multimap<grpc::string_ref, grpc::string_ref>& client_metadata =
           context->client_metadata();
-      for (std::multimap<grpc::string, grpc::string>::const_iterator iter =
-               client_metadata.begin();
+      for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator
+               iter = client_metadata.begin();
            iter != client_metadata.end(); ++iter) {
-        context->AddTrailingMetadata((*iter).first, (*iter).second);
+        context->AddTrailingMetadata(ToString(iter->first),
+                                     ToString(iter->second));
       }
     }
     if (request->has_param() && request->param().check_auth_context()) {
@@ -182,12 +184,12 @@ class TestServiceImpl : public ::grpc::cpp::test::util::TestService::Service {
     EchoRequest request;
     response->set_message("");
     int cancel_after_reads = 0;
-    const std::multimap<grpc::string, grpc::string> client_initial_metadata =
-        context->client_metadata();
+    const std::multimap<grpc::string_ref, grpc::string_ref>&
+        client_initial_metadata = context->client_metadata();
     if (client_initial_metadata.find(kServerCancelAfterReads) !=
         client_initial_metadata.end()) {
-      std::istringstream iss(
-          client_initial_metadata.find(kServerCancelAfterReads)->second);
+      std::istringstream iss(ToString(
+          client_initial_metadata.find(kServerCancelAfterReads)->second));
       iss >> cancel_after_reads;
       gpr_log(GPR_INFO, "cancel_after_reads %d", cancel_after_reads);
     }
@@ -721,14 +723,15 @@ TEST_F(End2endTest, RpcMaxMessageSize) {
   EXPECT_FALSE(s.ok());
 }
 
-bool MetadataContains(const std::multimap<grpc::string, grpc::string>& metadata,
-                      const grpc::string& key, const grpc::string& value) {
+bool MetadataContains(
+    const std::multimap<grpc::string_ref, grpc::string_ref>& metadata,
+    const grpc::string& key, const grpc::string& value) {
   int count = 0;
 
-  for (std::multimap<grpc::string, grpc::string>::const_iterator iter =
+  for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator iter =
            metadata.begin();
        iter != metadata.end(); ++iter) {
-    if ((*iter).first == key && (*iter).second == value) {
+    if (ToString(iter->first) == key && ToString(iter->second) == value) {
       count++;
     }
   }
diff --git a/test/cpp/end2end/generic_end2end_test.cc b/test/cpp/end2end/generic_end2end_test.cc
index de7eab8dc29..809eef058cf 100644
--- a/test/cpp/end2end/generic_end2end_test.cc
+++ b/test/cpp/end2end/generic_end2end_test.cc
@@ -160,7 +160,7 @@ class GenericEnd2endTest : public ::testing::Test {
                                    srv_cq_.get(), tag(4));
 
       verify_ok(srv_cq_.get(), 4, true);
-      EXPECT_EQ(server_host_, srv_ctx.host());
+      EXPECT_EQ(server_host_, srv_ctx.host().substr(0, server_host_.length()));
       EXPECT_EQ(kMethodName, srv_ctx.method());
       ByteBuffer recv_buffer;
       stream.Read(&recv_buffer, tag(5));
@@ -233,7 +233,7 @@ TEST_F(GenericEnd2endTest, SimpleBidiStreaming) {
                                srv_cq_.get(), tag(2));
 
   verify_ok(srv_cq_.get(), 2, true);
-  EXPECT_EQ(server_host_, srv_ctx.host());
+  EXPECT_EQ(server_host_, srv_ctx.host().substr(0, server_host_.length()));
   EXPECT_EQ(kMethodName, srv_ctx.method());
 
   std::unique_ptr<ByteBuffer> send_buffer =
diff --git a/test/cpp/util/cli_call.cc b/test/cpp/util/cli_call.cc
index d60cee9c024..9a769848a4b 100644
--- a/test/cpp/util/cli_call.cc
+++ b/test/cpp/util/cli_call.cc
@@ -51,14 +51,14 @@ void* tag(int i) { return (void*)(gpr_intptr)i; }
 
 Status CliCall::Call(std::shared_ptr<grpc::Channel> channel,
                      const grpc::string& method, const grpc::string& request,
-                     grpc::string* response, const MetadataContainer& metadata,
-                     MetadataContainer* server_initial_metadata,
-                     MetadataContainer* server_trailing_metadata) {
+                     grpc::string* response,
+                     const OutgoingMetadataContainer& metadata,
+                     IncomingMetadataContainer* server_initial_metadata,
+                     IncomingMetadataContainer* server_trailing_metadata) {
   std::unique_ptr<grpc::GenericStub> stub(new grpc::GenericStub(channel));
   grpc::ClientContext ctx;
   if (!metadata.empty()) {
-    for (std::multimap<grpc::string, grpc::string>::const_iterator iter =
-             metadata.begin();
+    for (OutgoingMetadataContainer::const_iterator iter = metadata.begin();
          iter != metadata.end(); ++iter) {
       ctx.AddMetadata(iter->first, iter->second);
     }
diff --git a/test/cpp/util/cli_call.h b/test/cpp/util/cli_call.h
index 7a3dcf2e9f6..2fbc9618b64 100644
--- a/test/cpp/util/cli_call.h
+++ b/test/cpp/util/cli_call.h
@@ -38,18 +38,22 @@
 
 #include <grpc++/channel.h>
 #include <grpc++/support/status.h>
+#include <grpc++/support/string_ref.h>
 
 namespace grpc {
 namespace testing {
 
 class CliCall GRPC_FINAL {
  public:
-  typedef std::multimap<grpc::string, grpc::string> MetadataContainer;
+  typedef std::multimap<grpc::string, grpc::string> OutgoingMetadataContainer;
+  typedef std::multimap<grpc::string_ref, grpc::string_ref>
+      IncomingMetadataContainer;
   static Status Call(std::shared_ptr<grpc::Channel> channel,
                      const grpc::string& method, const grpc::string& request,
-                     grpc::string* response, const MetadataContainer& metadata,
-                     MetadataContainer* server_initial_metadata,
-                     MetadataContainer* server_trailing_metadata);
+                     grpc::string* response,
+                     const OutgoingMetadataContainer& metadata,
+                     IncomingMetadataContainer* server_initial_metadata,
+                     IncomingMetadataContainer* server_trailing_metadata);
 };
 
 }  // namespace testing
diff --git a/test/cpp/util/cli_call_test.cc b/test/cpp/util/cli_call_test.cc
index 35bfad202f0..111a0e9f762 100644
--- a/test/cpp/util/cli_call_test.cc
+++ b/test/cpp/util/cli_call_test.cc
@@ -47,6 +47,7 @@
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
 #include "test/cpp/util/echo.grpc.pb.h"
+#include "test/cpp/util/string_ref_helper.h"
 
 using grpc::cpp::test::util::EchoRequest;
 using grpc::cpp::test::util::EchoResponse;
@@ -59,10 +60,11 @@ class TestServiceImpl : public ::grpc::cpp::test::util::TestService::Service {
   Status Echo(ServerContext* context, const EchoRequest* request,
               EchoResponse* response) GRPC_OVERRIDE {
     if (!context->client_metadata().empty()) {
-      for (std::multimap<grpc::string, grpc::string>::const_iterator iter =
-               context->client_metadata().begin();
+      for (std::multimap<grpc::string_ref, grpc::string_ref>::const_iterator
+               iter = context->client_metadata().begin();
            iter != context->client_metadata().end(); ++iter) {
-        context->AddInitialMetadata(iter->first, iter->second);
+        context->AddInitialMetadata(ToString(iter->first),
+                                    ToString(iter->second));
       }
     }
     context->AddTrailingMetadata("trailing_key", "trailing_value");
@@ -119,8 +121,9 @@ TEST_F(CliCallTest, SimpleRpc) {
   grpc::string request_bin, response_bin, expected_response_bin;
   EXPECT_TRUE(request.SerializeToString(&request_bin));
   EXPECT_TRUE(response.SerializeToString(&expected_response_bin));
-  std::multimap<grpc::string, grpc::string> client_metadata,
-      server_initial_metadata, server_trailing_metadata;
+  std::multimap<grpc::string, grpc::string> client_metadata;
+  std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata,
+      server_trailing_metadata;
   client_metadata.insert(std::pair<grpc::string, grpc::string>("key1", "val1"));
   Status s2 = CliCall::Call(channel_, kMethod, request_bin, &response_bin,
                             client_metadata, &server_initial_metadata,
diff --git a/test/cpp/util/grpc_cli.cc b/test/cpp/util/grpc_cli.cc
index 746d67deeb9..a4888efebe2 100644
--- a/test/cpp/util/grpc_cli.cc
+++ b/test/cpp/util/grpc_cli.cc
@@ -68,8 +68,10 @@
 #include <grpc++/channel.h>
 #include <grpc++/create_channel.h>
 #include <grpc++/credentials.h>
+#include <grpc++/support/string_ref.h>
 
 #include "test/cpp/util/cli_call.h"
+#include "test/cpp/util/string_ref_helper.h"
 #include "test/cpp/util/test_config.h"
 
 DEFINE_bool(enable_ssl, true, "Whether to use ssl/tls.");
@@ -104,16 +106,19 @@ void ParseMetadataFlag(
   }
 }
 
-void PrintMetadata(const std::multimap<grpc::string, grpc::string>& m,
-                   const grpc::string& message) {
+template <typename T>
+void PrintMetadata(const T& m, const grpc::string& message) {
   if (m.empty()) {
     return;
   }
   std::cout << message << std::endl;
-  for (std::multimap<grpc::string, grpc::string>::const_iterator iter =
-           m.begin();
-       iter != m.end(); ++iter) {
-    std::cout << iter->first << " : " << iter->second << std::endl;
+  grpc::string pair;
+  for (typename T::const_iterator iter = m.begin(); iter != m.end(); ++iter) {
+    pair.clear();
+    pair.append(iter->first.data(), iter->first.size());
+    pair.append(" : ");
+    pair.append(iter->second.data(), iter->second.size());
+    std::cout << pair << std::endl;
   }
 }
 
@@ -157,8 +162,9 @@ int main(int argc, char** argv) {
       grpc::CreateChannel(server_address, creds, grpc::ChannelArguments());
 
   grpc::string response;
-  std::multimap<grpc::string, grpc::string> client_metadata,
-      server_initial_metadata, server_trailing_metadata;
+  std::multimap<grpc::string, grpc::string> client_metadata;
+  std::multimap<grpc::string_ref, grpc::string_ref> server_initial_metadata,
+      server_trailing_metadata;
   ParseMetadataFlag(&client_metadata);
   PrintMetadata(client_metadata, "Sending client initial metadata:");
   grpc::Status s = grpc::testing::CliCall::Call(
diff --git a/test/cpp/util/string_ref_helper.cc b/test/cpp/util/string_ref_helper.cc
new file mode 100644
index 00000000000..4eb4fe03575
--- /dev/null
+++ b/test/cpp/util/string_ref_helper.cc
@@ -0,0 +1,44 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "test/cpp/util/string_ref_helper.h"
+
+namespace grpc {
+namespace testing {
+
+grpc::string ToString(const grpc::string_ref& r) {
+  return grpc::string(r.data(), r.size());
+}
+
+}  // namespace testing
+}  // namespace grpc
diff --git a/test/cpp/util/string_ref_helper.h b/test/cpp/util/string_ref_helper.h
new file mode 100644
index 00000000000..ac94bcd018a
--- /dev/null
+++ b/test/cpp/util/string_ref_helper.h
@@ -0,0 +1,47 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_TEST_CPP_UTIL_STRING_REF_HELPER_H
+#define GRPC_TEST_CPP_UTIL_STRING_REF_HELPER_H
+
+#include <grpc++/support/string_ref.h>
+
+namespace grpc {
+namespace testing {
+
+grpc::string ToString(const grpc::string_ref& r);
+
+}  // namespace testing
+}  // namespace grpc
+
+#endif  // GRPC_TEST_CPP_UTIL_STRING_REF_HELPER_H
diff --git a/tools/doxygen/Doxyfile.core.internal b/tools/doxygen/Doxyfile.core.internal
index 06f0f4ee834..7d5df66bc18 100644
--- a/tools/doxygen/Doxyfile.core.internal
+++ b/tools/doxygen/Doxyfile.core.internal
@@ -845,7 +845,6 @@ src/core/json/json_common.h \
 src/core/json/json_reader.h \
 src/core/json/json_writer.h \
 src/core/profiling/timers.h \
-src/core/profiling/timers_preciseclock.h \
 src/core/statistics/census_interface.h \
 src/core/statistics/census_rpc_stats.h \
 src/core/surface/byte_buffer_queue.h \
@@ -1058,6 +1057,7 @@ src/core/support/stack_lockfree.h \
 src/core/support/string.h \
 src/core/support/string_win32.h \
 src/core/support/thd_internal.h \
+src/core/support/time_precise.h \
 src/core/support/alloc.c \
 src/core/support/cmdline.c \
 src/core/support/cpu_iphone.c \
diff --git a/tools/run_tests/run_csharp.bat b/tools/run_tests/run_csharp.bat
index c86136767c2..310cfe0d2fe 100644
--- a/tools/run_tests/run_csharp.bat
+++ b/tools/run_tests/run_csharp.bat
@@ -8,7 +8,7 @@ cd /d %~dp0\..\..\src\csharp
 @rem set UUID variable to a random GUID, we will use it to put TestResults.xml to a dedicated directory, so that parallel test runs don't collide
 for /F %%i in ('powershell -Command "[guid]::NewGuid().ToString()"') do (set UUID=%%i)
 
-packages\NUnit.Runners.2.6.4\tools\nunit-console-x86.exe -labels "%1/bin/Debug/%1.dll" -work test-results/%UUID% || goto :error
+packages\NUnit.Runners.2.6.4\tools\nunit-console-x86.exe /domain:None -labels "%1/bin/Debug/%1.dll" -work test-results/%UUID% || goto :error
 
 endlocal
 
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index beb8805ff91..80854001d39 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -536,7 +536,8 @@ def _start_port_server(port_server_port):
   # if not running ==> start a new one
   # otherwise, leave it up
   try:
-    version = urllib2.urlopen('http://localhost:%d/version' % port_server_port).read()
+    version = urllib2.urlopen('http://localhost:%d/version' % port_server_port,
+                              timeout=1).read()
     running = True
   except Exception:
     running = False
@@ -554,12 +555,20 @@ def _start_port_server(port_server_port):
         stderr=subprocess.STDOUT,
         stdout=port_log)
     # ensure port server is up
+    waits = 0
     while True:
+      if waits > 10:
+        port_server.kill()
+        print "port_server failed to start"
+        sys.exit(1)
       try:
-        urllib2.urlopen('http://localhost:%d/get' % port_server_port).read()
+        urllib2.urlopen('http://localhost:%d/get' % port_server_port,
+                        timeout=1).read()
         break
       except urllib2.URLError:
+        print "waiting for port_server"
         time.sleep(0.5)
+        waits += 1
       except:
         port_server.kill()
         raise
diff --git a/tools/run_tests/sources_and_headers.json b/tools/run_tests/sources_and_headers.json
index 7b57096b7d3..d266c968a7d 100644
--- a/tools/run_tests/sources_and_headers.json
+++ b/tools/run_tests/sources_and_headers.json
@@ -12168,7 +12168,8 @@
       "src/core/support/stack_lockfree.h", 
       "src/core/support/string.h", 
       "src/core/support/string_win32.h", 
-      "src/core/support/thd_internal.h"
+      "src/core/support/thd_internal.h", 
+      "src/core/support/time_precise.h"
     ], 
     "language": "c", 
     "name": "gpr", 
@@ -12242,6 +12243,7 @@
       "src/core/support/thd_win32.c", 
       "src/core/support/time.c", 
       "src/core/support/time_posix.c", 
+      "src/core/support/time_precise.h", 
       "src/core/support/time_win32.c", 
       "src/core/support/tls_pthread.c"
     ]
@@ -12339,7 +12341,6 @@
       "src/core/json/json_reader.h", 
       "src/core/json/json_writer.h", 
       "src/core/profiling/timers.h", 
-      "src/core/profiling/timers_preciseclock.h", 
       "src/core/security/auth_filters.h", 
       "src/core/security/base64.h", 
       "src/core/security/credentials.h", 
@@ -12542,7 +12543,6 @@
       "src/core/profiling/basic_timers.c", 
       "src/core/profiling/stap_timers.c", 
       "src/core/profiling/timers.h", 
-      "src/core/profiling/timers_preciseclock.h", 
       "src/core/security/auth_filters.h", 
       "src/core/security/base64.c", 
       "src/core/security/base64.h", 
@@ -12818,7 +12818,6 @@
       "src/core/json/json_reader.h", 
       "src/core/json/json_writer.h", 
       "src/core/profiling/timers.h", 
-      "src/core/profiling/timers_preciseclock.h", 
       "src/core/statistics/census_interface.h", 
       "src/core/statistics/census_rpc_stats.h", 
       "src/core/surface/byte_buffer_queue.h", 
@@ -13006,7 +13005,6 @@
       "src/core/profiling/basic_timers.c", 
       "src/core/profiling/stap_timers.c", 
       "src/core/profiling/timers.h", 
-      "src/core/profiling/timers_preciseclock.h", 
       "src/core/statistics/census_interface.h", 
       "src/core/statistics/census_rpc_stats.h", 
       "src/core/surface/byte_buffer.c", 
@@ -13289,6 +13287,7 @@
       "test/cpp/util/echo_duplicate.pb.h", 
       "test/cpp/util/messages.grpc.pb.h", 
       "test/cpp/util/messages.pb.h", 
+      "test/cpp/util/string_ref_helper.h", 
       "test/cpp/util/subprocess.h"
     ], 
     "language": "c++", 
@@ -13298,6 +13297,8 @@
       "test/cpp/util/cli_call.h", 
       "test/cpp/util/create_test_channel.cc", 
       "test/cpp/util/create_test_channel.h", 
+      "test/cpp/util/string_ref_helper.cc", 
+      "test/cpp/util/string_ref_helper.h", 
       "test/cpp/util/subprocess.cc", 
       "test/cpp/util/subprocess.h"
     ]
diff --git a/vsprojects/Grpc.mak b/vsprojects/Grpc.mak
index e11653fbeb9..f8561abdaed 100644
--- a/vsprojects/Grpc.mak
+++ b/vsprojects/Grpc.mak
@@ -4752,8 +4752,8 @@ Debug\grpc++_test_config.lib: $(OUT_DIR)
 
 Debug\grpc++_test_util.lib: $(OUT_DIR)
 	echo Building grpc++_test_util
-    $(CC) $(CXXFLAGS) /Fo:$(OUT_DIR)\ $(REPO_ROOT)\test\cpp\util\cli_call.cc $(REPO_ROOT)\test\cpp\util\create_test_channel.cc $(REPO_ROOT)\test\cpp\util\subprocess.cc $(REPO_ROOT)\test\cpp\util\messages.pb.cc $(REPO_ROOT)\test\cpp\util\messages.grpc.pb.cc $(REPO_ROOT)\test\cpp\util\echo.pb.cc $(REPO_ROOT)\test\cpp\util\echo.grpc.pb.cc $(REPO_ROOT)\test\cpp\util\echo_duplicate.pb.cc $(REPO_ROOT)\test\cpp\util\echo_duplicate.grpc.pb.cc 
-	$(LIBTOOL) /OUT:"Debug\grpc++_test_util.lib" $(OUT_DIR)\cli_call.obj $(OUT_DIR)\create_test_channel.obj $(OUT_DIR)\subprocess.obj $(OUT_DIR)\messages.pb.obj $(OUT_DIR)\messages.grpc.pb.obj $(OUT_DIR)\echo.pb.obj $(OUT_DIR)\echo.grpc.pb.obj $(OUT_DIR)\echo_duplicate.pb.obj $(OUT_DIR)\echo_duplicate.grpc.pb.obj 
+    $(CC) $(CXXFLAGS) /Fo:$(OUT_DIR)\ $(REPO_ROOT)\test\cpp\util\cli_call.cc $(REPO_ROOT)\test\cpp\util\create_test_channel.cc $(REPO_ROOT)\test\cpp\util\string_ref_helper.cc $(REPO_ROOT)\test\cpp\util\subprocess.cc $(REPO_ROOT)\test\cpp\util\messages.pb.cc $(REPO_ROOT)\test\cpp\util\messages.grpc.pb.cc $(REPO_ROOT)\test\cpp\util\echo.pb.cc $(REPO_ROOT)\test\cpp\util\echo.grpc.pb.cc $(REPO_ROOT)\test\cpp\util\echo_duplicate.pb.cc $(REPO_ROOT)\test\cpp\util\echo_duplicate.grpc.pb.cc 
+	$(LIBTOOL) /OUT:"Debug\grpc++_test_util.lib" $(OUT_DIR)\cli_call.obj $(OUT_DIR)\create_test_channel.obj $(OUT_DIR)\string_ref_helper.obj $(OUT_DIR)\subprocess.obj $(OUT_DIR)\messages.pb.obj $(OUT_DIR)\messages.grpc.pb.obj $(OUT_DIR)\echo.pb.obj $(OUT_DIR)\echo.grpc.pb.obj $(OUT_DIR)\echo_duplicate.pb.obj $(OUT_DIR)\echo_duplicate.grpc.pb.obj 
 
 build_grpc++_unsecure:
 	msbuild grpc.sln /t:grpc++_unsecure /p:Configuration=Debug /p:Linkage-grpc_dependencies_zlib=static
diff --git a/vsprojects/gpr/gpr.vcxproj b/vsprojects/gpr/gpr.vcxproj
index 83c295625d8..3f8f554fd31 100644
--- a/vsprojects/gpr/gpr.vcxproj
+++ b/vsprojects/gpr/gpr.vcxproj
@@ -158,6 +158,7 @@
     <ClInclude Include="..\..\src\core\support\string.h" />
     <ClInclude Include="..\..\src\core\support\string_win32.h" />
     <ClInclude Include="..\..\src\core\support\thd_internal.h" />
+    <ClInclude Include="..\..\src\core\support\time_precise.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\..\src\core\support\alloc.c">
diff --git a/vsprojects/gpr/gpr.vcxproj.filters b/vsprojects/gpr/gpr.vcxproj.filters
index 64b90924ab4..b6ac061e05f 100644
--- a/vsprojects/gpr/gpr.vcxproj.filters
+++ b/vsprojects/gpr/gpr.vcxproj.filters
@@ -218,6 +218,9 @@
     <ClInclude Include="..\..\src\core\support\thd_internal.h">
       <Filter>src\core\support</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\src\core\support\time_precise.h">
+      <Filter>src\core\support</Filter>
+    </ClInclude>
   </ItemGroup>
 
   <ItemGroup>
diff --git a/vsprojects/grpc/grpc.vcxproj b/vsprojects/grpc/grpc.vcxproj
index b17eea9235d..1fa7e4b4f13 100644
--- a/vsprojects/grpc/grpc.vcxproj
+++ b/vsprojects/grpc/grpc.vcxproj
@@ -307,7 +307,6 @@
     <ClInclude Include="..\..\src\core\json\json_reader.h" />
     <ClInclude Include="..\..\src\core\json\json_writer.h" />
     <ClInclude Include="..\..\src\core\profiling\timers.h" />
-    <ClInclude Include="..\..\src\core\profiling\timers_preciseclock.h" />
     <ClInclude Include="..\..\src\core\statistics\census_interface.h" />
     <ClInclude Include="..\..\src\core\statistics\census_rpc_stats.h" />
     <ClInclude Include="..\..\src\core\surface\byte_buffer_queue.h" />
diff --git a/vsprojects/grpc/grpc.vcxproj.filters b/vsprojects/grpc/grpc.vcxproj.filters
index a955e9e9934..b22818aebd0 100644
--- a/vsprojects/grpc/grpc.vcxproj.filters
+++ b/vsprojects/grpc/grpc.vcxproj.filters
@@ -680,9 +680,6 @@
     <ClInclude Include="..\..\src\core\profiling\timers.h">
       <Filter>src\core\profiling</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\src\core\profiling\timers_preciseclock.h">
-      <Filter>src\core\profiling</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\src\core\statistics\census_interface.h">
       <Filter>src\core\statistics</Filter>
     </ClInclude>
diff --git a/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj b/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj
index a692c48f81d..3883a328e09 100644
--- a/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj
+++ b/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj
@@ -290,7 +290,6 @@
     <ClInclude Include="..\..\src\core\json\json_reader.h" />
     <ClInclude Include="..\..\src\core\json\json_writer.h" />
     <ClInclude Include="..\..\src\core\profiling\timers.h" />
-    <ClInclude Include="..\..\src\core\profiling\timers_preciseclock.h" />
     <ClInclude Include="..\..\src\core\statistics\census_interface.h" />
     <ClInclude Include="..\..\src\core\statistics\census_rpc_stats.h" />
     <ClInclude Include="..\..\src\core\surface\byte_buffer_queue.h" />
diff --git a/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj.filters b/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj.filters
index 1c4036d464b..d12abc0ad70 100644
--- a/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj.filters
+++ b/vsprojects/grpc_unsecure/grpc_unsecure.vcxproj.filters
@@ -578,9 +578,6 @@
     <ClInclude Include="..\..\src\core\profiling\timers.h">
       <Filter>src\core\profiling</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\src\core\profiling\timers_preciseclock.h">
-      <Filter>src\core\profiling</Filter>
-    </ClInclude>
     <ClInclude Include="..\..\src\core\statistics\census_interface.h">
       <Filter>src\core\statistics</Filter>
     </ClInclude>