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 3bbf6827f52ded2a38f03c5f2bd91ce1cb1d8748..bd533bdf739b89dfe98b794d6c14cd09d56f4b10 100644
--- a/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
+++ b/talk/app/webrtc/java/jni/androidmediaencoder_jni.cc
@@ -103,6 +103,8 @@ class MediaCodecVideoEncoder : public webrtc::VideoEncoder,
 
   int GetTargetFramerate() override;
 
+  const char* ImplementationName() const override;
+
  private:
   // CHECK-fail if not running on |codec_thread_|.
   void CheckOnCodecThread();
@@ -904,6 +906,10 @@ 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);