Initialize based on frame sizes in VideoTrackRecorder

content/renderer/media/video_track_recorder.h

 // 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.
 
 #ifndef CONTENT_RENDERER_MEDIA_VIDEO_TRACK_RECORDER_H_
 #define CONTENT_RENDERER_MEDIA_VIDEO_TRACK_RECORDER_H_
 
 #include <memory>
 
 #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"
 #include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
 
 namespace media {
 class VideoFrame;
 }  // namespace media
 
 namespace content {
@@ skipping 27 matching lines @@
   ~VideoTrackRecorder() override;
 
   void Pause();
   void Resume();
 
   void OnVideoFrameForTesting(const scoped_refptr<media::VideoFrame>& frame,
                               base::TimeTicks capture_time);
  private:
   friend class VideoTrackRecorderTest;
 
+  void InitializeEncoder(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_;
 
   // 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_;

[mcasas, 2016/07/08 22:59:27]

Don't extend this class' inner state (i.e. # member 
variables): instead, bind these variables from the 
constructor VideoTrackRecorder() to InitializeEncoder().

[emircan, 2016/07/12 01:00:35]

Done. However, I still need to hold onto this info for OnVideoFrameForTesting
calls. I will bind all these in a callback for that purpose.

+
+  // Used to track the paused state during the initialization process.
+  bool paused_before_init_;
+
+  base::WeakPtrFactory<VideoTrackRecorder> weak_ptr_factory_;

[mcasas, 2016/07/08 22:59:27]

This is not used in favour of base::Unretained(this)
to PostTask() to InitializeEncoder() in constructor.
I'd say use it because it's more self documenting,
and we won't depend on MSVSink::DisconnectFromTrack()
specifics, but I'll leave it to you.

[emircan, 2016/07/12 01:00:35]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(VideoTrackRecorder);
 };
 
 }  // namespace content
 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_TRACK_RECORDER_H_