[chttp2] Enable new huffman encoder by default (#30989)

bazel/experiments.bzl

@@ -18,12 +18,6 @@
 
 EXPERIMENTS = {
     "dbg": {
-        "core_end2end_tests": [
-            "new_hpack_huffman_decoder",
-        ],
-        "hpack_test": [
-            "new_hpack_huffman_decoder",
-        ],
     },
     "off": {
         "core_end2end_test": [
@@ -51,6 +45,9 @@ EXPERIMENTS = {
         ],
     },
     "on": {
+        "core_end2end_tests": [
+            "new_hpack_huffman_decoder",
+        ],
         "endpoint_test": [
             "tcp_read_chunks",
         ],
@@ -61,6 +58,9 @@ EXPERIMENTS = {
             "flow_control_fixes",
             "tcp_read_chunks",
         ],
+        "hpack_test": [
+            "new_hpack_huffman_decoder",
+        ],
     },
     "opt": {
     },

src/core/lib/experiments/experiments.cc

@@ -53,11 +53,6 @@ const char* const description_posix_event_engine_enable_polling =
     "If set, enables polling on the default posix event engine.";
 const char* const description_free_large_allocator =
     "If set, return all free bytes from a \042big\042 allocator";
-#ifdef NDEBUG
-const bool kDefaultForDebugOnly = false;
-#else
-const bool kDefaultForDebugOnly = true;
-#endif
 }  // namespace
 
 namespace grpc_core {
@@ -72,8 +67,7 @@ const ExperimentMetadata g_experiment_metadata[] = {
      false},
     {"unconstrained_max_quota_buffer_size",
      description_unconstrained_max_quota_buffer_size, false},
-    {"new_hpack_huffman_decoder", description_new_hpack_huffman_decoder,
+    {"new_hpack_huffman_decoder", description_new_hpack_huffman_decoder, true},
-     kDefaultForDebugOnly},
     {"event_engine_client", description_event_engine_client, false},
     {"monitoring_experiment", description_monitoring_experiment, true},
     {"promise_based_client_call", description_promise_based_client_call, false},

src/core/lib/experiments/experiments.yaml

@@ -94,8 +94,8 @@
 - name: new_hpack_huffman_decoder
   description:
     New HPACK huffman decoder - should be much faster than the existing implementation.
-  default: debug
+  default: true
-  expiry: 2023/01/01
+  expiry: 2023/03/01
   owner: ctiller@google.com
   test_tags: ["core_end2end_tests", "hpack_test"]
 - name: event_engine_client