RESOURCE_UTILIZATION in VideoFrameMetadata, a consumer feedback signal.

content/browser/renderer_host/media/video_capture_controller.h

 // Copyright (c) 2012 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.
 //
 // VideoCaptureController is the glue between a VideoCaptureDevice and all
 // VideoCaptureHosts that have connected to it. A controller exists on behalf of
 // one (and only one) VideoCaptureDevice; both are owned by the
 // VideoCaptureManager.
 //
 // The VideoCaptureController is responsible for:
@@ skipping 90 matching lines @@
   int GetActiveClientCount() const;
 
   // API called directly by VideoCaptureManager in case the device is
   // prematurely closed.
   void StopSession(int session_id);
 
   // Return a buffer with id |buffer_id| previously given in
   // VideoCaptureControllerEventHandler::OnBufferReady. In the case that the
   // buffer was backed by a texture, |sync_point| will be waited on before
   // destroying or recycling the texture, to synchronize with texture users in
-  // the renderer process.
+  // the renderer process. If the consumer provided resource utilization
+  // feedback, this will be passed here (-1.0 indicates no feedback).
   void ReturnBuffer(VideoCaptureControllerID id,
                     VideoCaptureControllerEventHandler* event_handler,
                     int buffer_id,
-                    uint32 sync_point);
+                    uint32 sync_point,
+                    double consumer_resource_utilization);
 
   const media::VideoCaptureFormat& GetVideoCaptureFormat() const;
 
   bool has_received_frames() const { return has_received_frames_; }
 
   // Worker functions on IO thread. Called by the VideoCaptureDeviceClient.
   void DoIncomingCapturedVideoFrameOnIOThread(
       scoped_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
       const scoped_refptr<media::VideoFrame>& frame,
       const base::TimeTicks& timestamp);
@@ skipping 30 matching lines @@
   media::VideoCaptureFormat video_capture_format_;
 
   base::WeakPtrFactory<VideoCaptureController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_CONTROLLER_H_