cc: Add support for sending BeginFrames for video.

cc/scheduler/video_frame_controller.h

+// Copyright 2013 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 CC_SCHEDULER_VIDEO_FRAME_CONTROLLER_H_
+#define CC_SCHEDULER_VIDEO_FRAME_CONTROLLER_H_
+
+#include "cc/base/cc_export.h"
+#include "cc/output/begin_frame_args.h"
+
+namespace cc {
+
+class VideoFrameController;
+
+class CC_EXPORT VideoFrameControllerClient {
+ public:
+  virtual void AddVideoFrameController(VideoFrameController* controller) = 0;
+  virtual void RemoveVideoFrameController(VideoFrameController* controller) = 0;
+
+ protected:
+  virtual ~VideoFrameControllerClient() {}
+};
+
+// TODO(sunnyps): Consider making this a BeginFrameObserver some day.
+class CC_EXPORT VideoFrameController {
+ public:
+  virtual void OnBeginFrame(const BeginFrameArgs& args) = 0;
+
+ protected:
+  virtual ~VideoFrameController() {}
+};
+
+}  // namespace cc
+
+#endif  // CC_SCHEDULER_VIDEO_FRAME_CONTROLLER_H_