Initialize based on frame sizes in VideoTrackRecorder

content/renderer/media/video_track_recorder.h

Index: content/renderer/media/video_track_recorder.h
diff --git a/content/renderer/media/video_track_recorder.h b/content/renderer/media/video_track_recorder.h
index 5e624549224362132c2a842d31db65ae3d0369d6..11d2cd64dbc1760836bf48e409a4152a93c94f4d 100644
--- a/content/renderer/media/video_track_recorder.h
+++ b/content/renderer/media/video_track_recorder.h
@@ -9,6 +9,8 @@
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/thread_checker.h"
 #include "content/public/common/features.h"
 #include "content/public/renderer/media_stream_video_sink.h"
@@ -56,15 +58,41 @@ class CONTENT_EXPORT VideoTrackRecorder
  private:
   friend class VideoTrackRecorderTest;
 
+  void ReceiveFirstFrameOnIOThread(
+      const scoped_refptr<media::VideoFrame>& frame,
+      base::TimeTicks capture_time);
+  void InitializeEncoderOnMainThread(
+      const scoped_refptr<media::VideoFrame>& frame,
+      base::TimeTicks capture_time);
+
   // Used to check that we are destroyed on the same thread we were created.
   base::ThreadChecker main_render_thread_checker_;
 
+  // Used to post initialization on the same thread we were created.
+  const scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+
+  // Task runner where frame encode callbacks must happen.
+  scoped_refptr<base::SingleThreadTaskRunner> origin_task_runner_;
+
   // We need to hold on to the Blink track to remove ourselves on dtor.
   blink::WebMediaStreamTrack track_;
 
   // Inner class to encode using whichever codec is configured.
   scoped_refptr<Encoder> encoder_;
 
+  // Parameters that would be passed to the underlying |encoder_|.
+  const CodecId codec_;
+  const OnEncodedVideoCB on_encoded_video_callback_;
+  const int32_t bits_per_second_;
+
+  // Used to track the paused state during the initialization process.
+  bool paused_before_init_;
+
+  // Used to mark that initialization task is posted.
+  bool is_first_frame_received_for_initialization_;
+
+  base::WeakPtrFactory<VideoTrackRecorder> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoTrackRecorder);
 };