Activate LayerImpl tree with sync+push instead of pointer swap

cc/video_frame_provider_client_impl.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_VIDEO_FRAME_PROVIDER_CLIENT_IMPL_H_
+#define CC_VIDEO_FRAME_PROVIDER_CLIENT_IMPL_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
+#include "cc/video_frame_provider.h"
+#include "ui/gfx/transform.h"
+
+namespace media {
+class VideoFrame;
+}
+
+namespace cc {
+class VideoLayerImpl;
+
+class VideoFrameProviderClientImpl :
+    public VideoFrameProvider::Client,
+    public base::RefCounted<VideoFrameProviderClientImpl> {
+ public:
+  static scoped_refptr<VideoFrameProviderClientImpl> Create(
+      VideoFrameProvider* provider);
+
+  void set_active_video_layer(VideoLayerImpl* video_layer) {
+    active_video_layer_ = video_layer;
+  }
+
+  void Stop();
+  bool Stopped() const { return !provider_; }
+
+  media::VideoFrame* AcquireLockAndCurrentFrame();
+  void PutCurrentFrame(media::VideoFrame* frame);
+  void ReleaseLock();
+  const gfx::Transform& stream_texture_matrix() const {
+    return stream_texture_matrix_;
+  }
+
+  // VideoFrameProvider::Client implementation.
+  virtual void StopUsingProvider() OVERRIDE; // Callable on any thread.
+  virtual void DidReceiveFrame() OVERRIDE; // Callable on impl thread.
+  virtual void DidUpdateMatrix(const float*) OVERRIDE; // Callable on impl thread.
+
+ private:
+  explicit VideoFrameProviderClientImpl(VideoFrameProvider* provider);
+  friend class base::RefCounted<VideoFrameProviderClientImpl>;
+  virtual ~VideoFrameProviderClientImpl();
+
+  VideoLayerImpl* active_video_layer_;
+
+  // Guards the destruction of provider_ and the frame that it provides
+  base::Lock provider_lock_;
+  VideoFrameProvider* provider_;
+
+  gfx::Transform stream_texture_matrix_;
+};
+
+}  // namespace cc
+
+#endif  // CC_VIDEO_FRAME_PROVIDER_CLIENT_IMPL_H_