Reland of Add content type information to encoded images and corresponding rtp extension header

webrtc/modules/video_coding/include/mock/mock_vcm_callbacks.h

Index: webrtc/modules/video_coding/include/mock/mock_vcm_callbacks.h
diff --git a/webrtc/modules/video_coding/include/mock/mock_vcm_callbacks.h b/webrtc/modules/video_coding/include/mock/mock_vcm_callbacks.h
index 8a53c1d31a19593fb7b76fede6f1201d72704857..b8f27e698cfcb0c32aed41ae33aaae9e30ffe972 100644
--- a/webrtc/modules/video_coding/include/mock/mock_vcm_callbacks.h
+++ b/webrtc/modules/video_coding/include/mock/mock_vcm_callbacks.h
@@ -33,7 +33,10 @@ class MockVCMReceiveCallback : public VCMReceiveCallback {
   MockVCMReceiveCallback() {}
   virtual ~MockVCMReceiveCallback() {}
 
-  MOCK_METHOD2(FrameToRender, int32_t(VideoFrame&, rtc::Optional<uint8_t>));
+  // TODO(ilnik): Remove using ... once deprecation is done.
+  using VCMReceiveCallback::FrameToRender;
+  MOCK_METHOD3(FrameToRender,
+               int32_t(VideoFrame&, rtc::Optional<uint8_t>, VideoContentType));
   MOCK_METHOD1(ReceivedDecodedReferenceFrame, int32_t(const uint64_t));
   MOCK_METHOD1(OnIncomingPayloadType, void(int));
   MOCK_METHOD1(OnDecoderImplementationName, void(const char*));