Add support for multiple pixel formats in VideoFrameBuffer

webrtc/api/video/i420_buffer.cc

Index: webrtc/api/video/i420_buffer.cc
diff --git a/webrtc/api/video/i420_buffer.cc b/webrtc/api/video/i420_buffer.cc
index 32c73eac67de98c822bcb818642e1d7d5fa9799b..51d83c9df58ba90508bb263434ebfca3c78d8e4e 100644
--- a/webrtc/api/video/i420_buffer.cc
+++ b/webrtc/api/video/i420_buffer.cc
@@ -136,6 +136,10 @@ void I420Buffer::InitializeData() {
          I420DataSize(height_, stride_y_, stride_u_, stride_v_));
 }
 
+VideoFrameBuffer::Type I420Buffer::type() const {
+  return Type::kI420;
+}
+
 int I420Buffer::width() const {
   return width_;
 }
@@ -164,14 +168,6 @@ int I420Buffer::StrideV() const {
   return stride_v_;
 }
 
-void* I420Buffer::native_handle() const {
-  return nullptr;
-}
-
-rtc::scoped_refptr<VideoFrameBuffer> I420Buffer::NativeToI420Buffer() {
-  return this;
-}
-
 uint8_t* I420Buffer::MutableDataY() {
   return const_cast<uint8_t*>(DataY());
 }