Add support for multiple pixel formats in VideoFrameBuffer

webrtc/common_video/include/video_frame_buffer.h

Index: webrtc/common_video/include/video_frame_buffer.h
diff --git a/webrtc/common_video/include/video_frame_buffer.h b/webrtc/common_video/include/video_frame_buffer.h
index dfdd480b5dc48b2a341669dcdc289f596195e54c..2454ccee48b1cf87d395368615020c827ea1323f 100644
--- a/webrtc/common_video/include/video_frame_buffer.h
+++ b/webrtc/common_video/include/video_frame_buffer.h
@@ -30,6 +30,7 @@ class NativeHandleBuffer : public VideoFrameBuffer {
  public:
   NativeHandleBuffer(void* native_handle, int width, int height);
 
+  PixelFormat Format() const override;
   int width() const override;
   int height() const override;
   const uint8_t* DataY() const override;
@@ -47,7 +48,7 @@ class NativeHandleBuffer : public VideoFrameBuffer {
   const int height_;
 };
 
-class WrappedI420Buffer : public webrtc::VideoFrameBuffer {
+class WrappedI420Buffer : public I420BufferInterface {
  public:
   WrappedI420Buffer(int width,
                     int height,
@@ -68,10 +69,6 @@ class WrappedI420Buffer : public webrtc::VideoFrameBuffer {
   int StrideU() const override;
   int StrideV() const override;
 
-  void* native_handle() const override;
-
-  rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
-
  private:
   friend class rtc::RefCountedObject<WrappedI420Buffer>;
   ~WrappedI420Buffer() override;