VideoCapturerDelegate: Retrieve supported/in-use format(s) for constraint negotiation

content/renderer/media/media_stream_video_source.h

 // Copyright 2014 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_MEDIA_STREAM_VIDEO_SOURCE_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 88 matching lines @@
   // An implementation must fetch the formats that can currently be used by
   // the source and call OnSupportedFormats when done.
   // |max_requested_height| and |max_requested_width| is the max height and
   // width set as a mandatory constraint if set when calling
   // MediaStreamVideoSource::AddTrack. If max height and max width is not set
   // |max_requested_height| and |max_requested_width| are 0.
   virtual void GetCurrentSupportedFormats(int max_requested_width,
                                           int max_requested_height) = 0;
   void OnSupportedFormats(const media::VideoCaptureFormats& formats);
 
-  // An implementation must starts capture frames using the resolution in
+  // An implementation must start capture frames using the resolution in
   // |params|. When the source has started or the source failed to start
   // OnStartDone must be called. An implementation must call
   // DeliverVideoFrame with the captured frames.
   // TODO(perkj): pass a VideoCaptureFormats instead of VideoCaptureParams for
   // subclasses to customize.
   virtual void StartSourceImpl(const media::VideoCaptureParams& params) = 0;
   void OnStartDone(bool success);
 
   // An implementation must immediately stop capture video frames and must not
   // call OnSupportedFormats after this method has been called. After this
@@ skipping 53 matching lines @@
   MediaStreamDependencyFactory* factory_;
   scoped_refptr<webrtc::VideoSourceInterface> adapter_;
   WebRtcVideoCapturerAdapter* capture_adapter_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoSource);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_