Use std::unique_ptr<> to pass frame ownership in DesktopCapturer impls.

webrtc/modules/desktop_capture/shared_desktop_frame.h

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_DESKTOP_CAPTURE_SHARED_DESKTOP_FRAME_H_
 #define WEBRTC_MODULES_DESKTOP_CAPTURE_SHARED_DESKTOP_FRAME_H_
 
 #include "webrtc/base/constructormagic.h"
+#include "webrtc/base/refcount.h"
 #include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 
 namespace webrtc {
 
 // SharedDesktopFrame is a DesktopFrame that may have multiple instances all
 // sharing the same buffer.
 class SharedDesktopFrame : public DesktopFrame {
  public:
   virtual ~SharedDesktopFrame();
 
+  static std::unique_ptr<SharedDesktopFrame> Wrap(
+      std::unique_ptr<DesktopFrame> desktop_frame);
+
+  // Deprecated.
+  // TODO(sergeyu): remove this method.
   static SharedDesktopFrame* Wrap(DesktopFrame* desktop_frame);
 
   // Returns the underlying instance of DesktopFrame.
   DesktopFrame* GetUnderlyingFrame();
 
   // Creates a clone of this object.
-  SharedDesktopFrame* Share();
+  std::unique_ptr<SharedDesktopFrame> Share();
 
   // Checks if the frame is currently shared. If it returns false it's
   // guaranteed that there are no clones of the object.
   bool IsShared();
 
  private:
-  class Core;
+  typedef rtc::RefCountedObject<std::unique_ptr<DesktopFrame>> Core;
 
   SharedDesktopFrame(rtc::scoped_refptr<Core> core);
 
   rtc::scoped_refptr<Core> core_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(SharedDesktopFrame);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_SHARED_DESKTOP_FRAME_H_