Support alpha channel recording for VPX in MediaRecorder

content/renderer/media_recorder/media_recorder_handler.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media_recorder/media_recorder_handler.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 252 matching lines @@
   for (const auto& video_recorder : video_recorders_)
     video_recorder->Resume();
   for (const auto& audio_recorder : audio_recorders_)
     audio_recorder->Resume();
   webm_muxer_->Resume();
 }
 
 void MediaRecorderHandler::OnEncodedVideo(
     const media::WebmMuxer::VideoParameters& params,
     std::unique_ptr<std::string> encoded_data,
+    std::unique_ptr<std::string> encoded_alpha,
     TimeTicks timestamp,
     bool is_key_frame) {
   DCHECK(main_render_thread_checker_.CalledOnValidThread());
 
   if (UpdateTracksAndCheckIfChanged()) {
     client_->onError("Amount of tracks in MediaStream has changed.");
     return;
   }
   if (!webm_muxer_)
     return;
-  if (!webm_muxer_->OnEncodedVideo(params, std::move(encoded_data), timestamp,
+  if (!webm_muxer_->OnEncodedVideo(params, std::move(encoded_data),
+                                   std::move(encoded_alpha), timestamp,
                                    is_key_frame)) {
     DLOG(ERROR) << "Error muxing video data";
     client_->onError("Error muxing video data");
   }
 }
 
 void MediaRecorderHandler::OnEncodedAudio(
     const media::AudioParameters& params,
     std::unique_ptr<std::string> encoded_data,
     base::TimeTicks timestamp) {
@@ skipping 79 matching lines @@
     recorder->OnData(audio_bus, timestamp);
 }
 
 void MediaRecorderHandler::SetAudioFormatForTesting(
     const media::AudioParameters& params) {
   for (const auto& recorder : audio_recorders_)
     recorder->OnSetFormat(params);
 }
 
 }  // namespace content