Move screen capturers from remoting/capturer to media/video/capturer/screen

remoting/capturer/video_frame_queue.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.
-
-#ifndef REMOTING_CAPTURER_VIDEO_FRAME_QUEUE_H_
-#define REMOTING_CAPTURER_VIDEO_FRAME_QUEUE_H_
-
-#include "base/compiler_specific.h"
-#include "base/memory/scoped_ptr.h"
-
-namespace remoting {
-
-class VideoFrame;
-
-// Represents a queue of reusable video frames. Provides access to the 'current'
-// frame - the frame that the caller is working with at the moment, and to
-// the 'previous' frame - the predecessor of the current frame swapped by
-// DoneWithCurrentFrame() call, if any.
-//
-// The caller is expected to (re)allocate frames if current_frame_needs_update()
-// is set. The caller can mark all frames in the queue for reallocation (when,
-// say, frame dimensions  change). The queue records which frames need updating
-// which the caller can query.
-class VideoFrameQueue {
- public:
-  VideoFrameQueue();
-  ~VideoFrameQueue();
-
-  // Moves to the next frame in the queue, moving the 'current' frame to become
-  // the 'previous' one.
-  void DoneWithCurrentFrame();
-
-  // Replaces the current frame with a new one allocated by the caller.
-  // The existing frame (if any) is destroyed.
-  void ReplaceCurrentFrame(scoped_ptr<VideoFrame> frame);
-
-  // Marks all frames obsolete and resets the previous frame pointer. No
-  // frames are freed though as the caller can still access them.
-  void SetAllFramesNeedUpdate();
-
-  VideoFrame* current_frame() const {
-    return frames_[current_].get();
-  }
-
-  bool current_frame_needs_update() const {
-    return !current_frame() || needs_update_[current_];
-  }
-
-  VideoFrame* previous_frame() const { return previous_; }
-
- private:
-  // Index of the current frame.
-  int current_;
-
-  static const int kQueueLength = 2;
-  scoped_ptr<VideoFrame> frames_[kQueueLength];
-
-  // True if the corresponding frame needs to be re-allocated.
-  bool needs_update_[kQueueLength];
-
-  // Points to the previous frame if any.
-  VideoFrame* previous_;
-
-  DISALLOW_COPY_AND_ASSIGN(VideoFrameQueue);
-};
-
-}  // namespace remoting
-
-#endif  // REMOTING_CAPTURER_VIDEO_FRAME_QUEUE_H_