Expose codec implementation names in stats.

talk/app/webrtc/java/jni/androidmediaencoder_jni.cc

Index: talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
diff --git a/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc b/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
index 246773c2bb6462a9161360f2cb5f71ece1ebcb05..041db1bc63c864558eb0a67c5886c3615693a808 100644
--- a/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
+++ b/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
@@ -106,6 +106,8 @@ class MediaCodecVideoEncoder : public webrtc::VideoEncoder,
 
   int GetTargetFramerate() override;
 
+  const char* ImplementationName() const override;
+
  private:
   // ResetCodecOnCodecThread() calls ReleaseOnCodecThread() and
   // InitEncodeOnCodecThread() in an attempt to restore the codec to an
@@ -948,6 +950,10 @@ int MediaCodecVideoEncoder::GetTargetFramerate() {
   return scale_ ? quality_scaler_.GetTargetFramerate() : -1;
 }
 
+const char* MediaCodecVideoEncoder::ImplementationName() const {
+  return "MediaCodec";
+}
+
 MediaCodecVideoEncoderFactory::MediaCodecVideoEncoderFactory() {
   JNIEnv* jni = AttachCurrentThreadIfNeeded();
   ScopedLocalRefFrame local_ref_frame(jni);