Reland of Drop frames until specified bitrate is achieved.

webrtc/api/video/video_frame.cc

Index: webrtc/api/video/video_frame.cc
diff --git a/webrtc/api/video/video_frame.cc b/webrtc/api/video/video_frame.cc
index 0e3efb2be18f7cee6eaece14a1492acc35e8e53e..b2647461c73b67d1fba827390da9633146aca18a 100644
--- a/webrtc/api/video/video_frame.cc
+++ b/webrtc/api/video/video_frame.cc
@@ -51,6 +51,10 @@ int VideoFrame::height() const {
   return video_frame_buffer_ ? video_frame_buffer_->height() : 0;
 }
 
+uint32_t VideoFrame::size() const {
+  return width() * height();
+}
+
 rtc::scoped_refptr<VideoFrameBuffer> VideoFrame::video_frame_buffer() const {
   return video_frame_buffer_;
 }