CroppingWindowCapturer::CreateCapturer() function to replace raw pointer version

webrtc/modules/desktop_capture/cropping_window_capturer.cc

 /*
  *  Copyright (c) 2014 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.
  */
 
@@ skipping 88 matching lines @@
       Result::SUCCESS,
       CreateCroppedDesktopFrame(std::move(screen_frame), window_rect));
 }
 
 #if !defined(WEBRTC_WIN)
 // static
 DesktopCapturer* CroppingWindowCapturer::Create(
     const DesktopCaptureOptions& options) {
   return DesktopCapturer::CreateWindowCapturer(options).release();
 }
+
+// static
+std::unique_ptr<DesktopCapturer> CroppingWindowCapturer::CreateCapturer(
+    const DesktopCaptureOptions& options) {
+  return DesktopCapturer::CreateWindowCapturer(options);
+}
 #endif
 
 }  // namespace webrtc