Allow shaped-desktop hosts to send shape only when it changes.

remoting/client/frame_consumer_proxy.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.
 
 // FrameConsumerProxy is used to allow a FrameConsumer on the UI thread to be
 // invoked by a Decoder on the decoder thread.  The Detach() method is used by
 // the proxy's owner before tearing down the FrameConsumer, to prevent any
 // further invokations reaching it.
 
 #ifndef REMOTING_CLIENT_FRAME_CONSUMER_PROXY_H_
 #define REMOTING_CLIENT_FRAME_CONSUMER_PROXY_H_
 
-#include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "remoting/client/frame_consumer.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace remoting {
 
-class FrameConsumerProxy
-    : public base::RefCountedThreadSafe<FrameConsumerProxy>,
-      public FrameConsumer {
+class FrameConsumerProxy : public FrameConsumer {
  public:
-  // Constructs a proxy for |frame_consumer| which will trampoline invocations
-  // to |frame_consumer_message_loop|.
-  FrameConsumerProxy(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
-                     const base::WeakPtr<FrameConsumer>& frame_consumer);
+  // Constructs a FrameConsumer proxy which can be passed to another thread,
+  // and will direct calls to |frame_consumer| on the thread from which the
+  // proxy was constructed.
+  FrameConsumerProxy(const base::WeakPtr<FrameConsumer>& frame_consumer);
+  ~FrameConsumerProxy() override;
 
   // FrameConsumer implementation.
   void ApplyBuffer(const webrtc::DesktopSize& view_size,
                    const webrtc::DesktopRect& clip_area,
                    webrtc::DesktopFrame* buffer,
                    const webrtc::DesktopRegion& region,
-                   const webrtc::DesktopRegion& shape) override;
+                   const webrtc::DesktopRegion* shape) override;
   void ReturnBuffer(webrtc::DesktopFrame* buffer) override;
   void SetSourceSize(const webrtc::DesktopSize& source_size,
                      const webrtc::DesktopVector& dpi) override;
   PixelFormat GetPixelFormat() override;
 
  private:
-  friend class base::RefCountedThreadSafe<FrameConsumerProxy>;
-  ~FrameConsumerProxy() override;
+  base::WeakPtr<FrameConsumer> frame_consumer_;
 
-  base::WeakPtr<FrameConsumer> frame_consumer_;
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
-
   PixelFormat pixel_format_;
 
   DISALLOW_COPY_AND_ASSIGN(FrameConsumerProxy);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_CLIENT_FRAME_CONSUMER_PROXY_H_