Use webrtc::DesktopCapturer for screen capturer implementation.

media/video/capture/screen/screen_capture_frame_queue.cc

 // 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.
 
 #include "media/video/capture/screen/screen_capture_frame_queue.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
-#include "media/video/capture/screen/screen_capture_frame.h"
+#include "base/logging.h"
+#include "base/threading/non_thread_safe.h"
+#include "media/video/capture/screen/shared_desktop_frame.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
 
 namespace media {
 
-ScreenCaptureFrameQueue::ScreenCaptureFrameQueue()
-    : current_(0),
-      previous_(NULL) {
-  SetAllFramesNeedUpdate();
-}
+ScreenCaptureFrameQueue::ScreenCaptureFrameQueue() : current_(0) {}
 
-ScreenCaptureFrameQueue::~ScreenCaptureFrameQueue() {
-}
+ScreenCaptureFrameQueue::~ScreenCaptureFrameQueue() {}
 
-void ScreenCaptureFrameQueue::DoneWithCurrentFrame() {
-  previous_ = current_frame();
+void ScreenCaptureFrameQueue::MoveToNextFrame() {
   current_ = (current_ + 1) % kQueueLength;
+
+  // Verify that the frame is not shared, i.e. that consumer has released it
+  // before attempting to capture again.
+  DCHECK(!frames_[current_] || !frames_[current_]->IsShared());
 }
 
 void ScreenCaptureFrameQueue::ReplaceCurrentFrame(
-    scoped_ptr<ScreenCaptureFrame> frame) {
-  frames_[current_] = frame.Pass();
-  needs_update_[current_] = false;
+    scoped_ptr<webrtc::DesktopFrame> frame) {
+  frames_[current_].reset(SharedDesktopFrame::Wrap(frame.release()));
 }
 
-void ScreenCaptureFrameQueue::SetAllFramesNeedUpdate() {
-  std::fill(needs_update_, needs_update_ + arraysize(needs_update_), true);
-  previous_ = NULL;
+void ScreenCaptureFrameQueue::Reset() {
+  for (int i = 0; i < kQueueLength; ++i)
+    frames_[i].reset();
 }
 
 }  // namespace media