Added a tiny comment header and TODOs.

src/core/ext/lb_policy/grpclb/grpclb.c

@@ -31,6 +31,14 @@
  *
  */
 
+/** Implementation of the gRPC LB policy.
+ *
+ * \see https://github.com/grpc/grpc/blob/master/doc/load-balancing.md */
+
+/* TODO(dgq):
+ * - Implement LB service forwarding (point 2c. in the doc's diagram).
+ */
+
 #include <string.h>
 
 #include <grpc/byte_buffer_reader.h>

test/cpp/grpclb/grpclb_test.cc

@@ -68,6 +68,8 @@ extern "C" {
 // - Send identical serverlist update
 // - Test reception of invalid serverlist
 // - Test pinging
+// - Test against a non-LB server. That server should return UNIMPLEMENTED and
+// the call should fail.
 
 namespace grpc {
 namespace {