[Chromoting] Implement DualBufferFrameConsumer

remoting/client/software_video_renderer.h

 // Copyright 2014 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_CLIENT_SOFTWARE_VIDEO_RENDERER_H_
 #define REMOTING_CLIENT_SOFTWARE_VIDEO_RENDERER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 26 matching lines @@
 
 // Implementation of VideoRenderer interface that decodes frame on CPU (on a
 // decode thread) and then passes decoded frames to a FrameConsumer.
 class SoftwareVideoRenderer : public protocol::VideoRenderer,
                               public protocol::VideoStub {
  public:
   // The renderer can be created on any thread but afterwards all methods must
   // be called on the same thread.
   explicit SoftwareVideoRenderer(protocol::FrameConsumer* consumer);
 
+  // std::unique_ptr version constructor that owns the consumer.

[Sergey Ulanov, 2016/07/20 18:39:26]

Suggest rewording: "Same as above, but takes ownership of the |consumer|."

[Yuwei, 2016/07/21 00:07:32]

Done.

+  explicit SoftwareVideoRenderer(
+      std::unique_ptr<protocol::FrameConsumer> consumer);
+
   // Deprecated constructor. TODO(yuweih): remove.
   // Constructs the renderer and initializes it immediately. Caller should not
   // call Initialize() after using this constructor.
   // All methods must be called on the same thread the renderer is created. The
   // |decode_task_runner_| is used to decode the video packets. |consumer| and
   // |stats_consumer| must outlive the renderer. |stats_consumer| may be
   // nullptr, performance tracking is disabled in that case.
   SoftwareVideoRenderer(

[Sergey Ulanov, 2016/07/20 18:39:26]

Please remove this constructor. It's used only in tests, which can be easily
updated to use Initialize()

[Yuwei, 2016/07/21 00:07:32]

Done.

       scoped_refptr<base::SingleThreadTaskRunner> decode_task_runner,
       protocol::FrameConsumer* consumer,
       protocol::FrameStatsConsumer* stats_consumer);
   ~SoftwareVideoRenderer() override;
 
   // VideoRenderer interface.
   bool Initialize(const ClientContext& client_context,
                   protocol::FrameStatsConsumer* stats_consumer) override;
   void OnSessionConfig(const protocol::SessionConfig& config) override;
   protocol::VideoStub* GetVideoStub() override;
   protocol::FrameConsumer* GetFrameConsumer() override;
   protocol::FrameStatsConsumer* GetFrameStatsConsumer() override;
 
   // protocol::VideoStub interface.
   void ProcessVideoPacket(std::unique_ptr<VideoPacket> packet,
                           const base::Closure& done) override;
 
  private:
   void RenderFrame(std::unique_ptr<protocol::FrameStats> stats,
                    const base::Closure& done,
                    std::unique_ptr<webrtc::DesktopFrame> frame);
   void OnFrameRendered(std::unique_ptr<protocol::FrameStats> stats,
                        const base::Closure& done);
 
   scoped_refptr<base::SingleThreadTaskRunner> decode_task_runner_;
+
+  // |owned_consumer_| and |consumer_| should refer to the same object if
+  // |owned_consumer_| is not null.
+  std::unique_ptr<protocol::FrameConsumer> owned_consumer_;
   protocol::FrameConsumer* const consumer_;
+
   protocol::FrameStatsConsumer* stats_consumer_ = nullptr;
 
   std::unique_ptr<VideoDecoder> decoder_;
 
   webrtc::DesktopSize source_size_;
   webrtc::DesktopVector source_dpi_;
 
   base::ThreadChecker thread_checker_;
 
   base::WeakPtrFactory<SoftwareVideoRenderer> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SoftwareVideoRenderer);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_CLIENT_SOFTWARE_VIDEO_RENDERER_H_