Enable new getUserMedia audio constraints algorithm behind a flag.

content/renderer/media/video_track_adapter.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_VIDEO_TRACK_ADAPTER_H_
 #define CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 16 matching lines @@
       double min_aspect_ratio,
       double max_aspect_ratio,
       double max_frame_rate,
       const base::Optional<gfx::Size>& expected_native_resolution);
   VideoTrackAdapterSettings(const VideoTrackAdapterSettings& other);
   VideoTrackAdapterSettings& operator=(const VideoTrackAdapterSettings& other);
   int max_width;
   int max_height;
   double min_aspect_ratio;
   double max_aspect_ratio;
+  // A |max_frame_rate| of zero is used to signal that no frame-rate adjustment
+  // is necessary.
+  // TODO(guidou): Change this to base::Optional. http://crbug.com/734528
   double max_frame_rate;
   // If supplied, this can be used to detect frames from a rotated device.
   base::Optional<gfx::Size> expected_native_size;
 };
 
 // VideoTrackAdapter is a helper class used by MediaStreamVideoSource used for
 // adapting the video resolution from a source implementation to the resolution
 // a track requires. Different tracks can have different resolution constraints.
 // The constraints can be set as max width and height as well as max and min
 // aspect ratio.
@@ skipping 93 matching lines @@
 
   // Frame rate configured on the video source, accessed on the IO-thread.
   float source_frame_rate_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoTrackAdapter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_TRACK_ADAPTER_H_