Expose codec implementation names in stats.

webrtc/test/fake_encoder.cc

Index: webrtc/test/fake_encoder.cc
diff --git a/webrtc/test/fake_encoder.cc b/webrtc/test/fake_encoder.cc
index 165fd3e536eb8d5af7dffff56c9eabdffcae0fe9..72df40f9a51690f3b81bd0c25f30cab36c23dff0 100644
--- a/webrtc/test/fake_encoder.cc
+++ b/webrtc/test/fake_encoder.cc
@@ -132,6 +132,11 @@ int32_t FakeEncoder::SetRates(uint32_t new_target_bitrate, uint32_t framerate) {
   return 0;
 }
 
+const char* FakeEncoder::kImplementationName = "fake_encoder";
+const char* FakeEncoder::ImplementationName() const {
+  return kImplementationName;
+}
+
 FakeH264Encoder::FakeH264Encoder(Clock* clock)
     : FakeEncoder(clock), callback_(NULL), idr_counter_(0) {
   FakeEncoder::RegisterEncodeCompleteCallback(this);