MediaStream Recorder: Support VP9 encoder

media/capture/webm_muxer.h

Index: media/capture/webm_muxer.h
diff --git a/media/capture/webm_muxer.h b/media/capture/webm_muxer.h
index 2d25c46a66a40342f8f2e4484dafee2662bf677e..00fd4ab6a17e27b5c5b470c8e94aec03d99a3a9f 100644
--- a/media/capture/webm_muxer.h
+++ b/media/capture/webm_muxer.h
@@ -40,7 +40,8 @@ class MEDIA_EXPORT WebmMuxer : public NON_EXPORTED_BASE(mkvmuxer::IMkvWriter) {
   // either any file header or a SingleBlock.
   using WriteDataCB = base::Callback<void(base::StringPiece)>;
 
-  explicit WebmMuxer(const WriteDataCB& write_data_callback);
+  // |use_vp9| forces using VP9, otherwise VP8 will be used by default.
+  WebmMuxer(bool use_vp9, const WriteDataCB& write_data_callback);

[sandersd (OOO until July 31), 2015/10/08 00:11:04]

I would vastly prefer an enum over a bool for this. Ideally it would be passed
when the track is added, but I won't demand that now.

[mcasas, 2015/10/08 18:08:46]

Done.

   ~WebmMuxer() override;
 
   // Adds a |video_frame| with |encoded_data.data()| to WebM Segment.
@@ -69,6 +70,9 @@ class MEDIA_EXPORT WebmMuxer : public NON_EXPORTED_BASE(mkvmuxer::IMkvWriter) {
   // Used to DCHECK that we are called on the correct thread.
   base::ThreadChecker thread_checker_;
 
+  // Force using VP9 for video encoding, otherwise VP8 will be used by default.
+  const bool use_vp9_;
+
   // A caller-side identifier to interact with |segment_|, initialised upon
   // first frame arrival by AddVideoTrack().
   uint64_t track_index_;