Wrap ScreenCapturer with ScreenCapturerDifferWrapper

webrtc/modules/desktop_capture/screen_capturer_win.cc

 /*
  *  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.
  */
 
 #include "webrtc/modules/desktop_capture/screen_capturer.h"
 
 #include <memory>
 #include <utility>
 
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
+#include "webrtc/modules/desktop_capture/screen_capturer_differ_wrapper.h"
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h"
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.h"
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_magnifier.h"
 
 namespace webrtc {
 
 // static
 ScreenCapturer* ScreenCapturer::Create(const DesktopCaptureOptions& options) {
   std::unique_ptr<ScreenCapturer> capturer;
-  if (options.allow_directx_capturer() &&
-      ScreenCapturerWinDirectx::IsSupported()) {
+  if (options.allow_directx_capturer()) {

[Sergey Ulanov, 2016/09/09 17:33:51]

Do you still need to check IsSupported() here?

[Hzj_jie, 2016/09/14 19:35:31]

Oh, yes, I still need to check IsSupport here.

This should be able to be caught by the test case. I will also update the
screen_capturer_unittest.cc

     capturer.reset(new ScreenCapturerWinDirectx(options));
-  } else {
+  }
+  if (!capturer) {

[Sergey Ulanov, 2016/09/09 17:33:51]

else is still appropriate here.

[Hzj_jie, 2016/09/14 19:35:31]

Done.

     capturer.reset(new ScreenCapturerWinGdi(options));
   }
+  if (options.allow_use_magnification_api()) {
+    capturer.reset(new ScreenCapturerWinMagnifier(std::move(capturer)));
+  }
 
-  if (options.allow_use_magnification_api())
-    return new ScreenCapturerWinMagnifier(std::move(capturer));
+  if (options.detect_updated_region()) {
+    capturer.reset(new ScreenCapturerDifferWrapper(std::move(capturer)));
+  }
 
   return capturer.release();
 }
 
 }  // namespace webrtc