Add reference counter of DxgiDuplicatorController to unload DXGI components

webrtc/modules/desktop_capture/win/dxgi_context.h

 /*
  *  Copyright (c) 2017 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_WIN_DXGI_CONTEXT_H_
 #define WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_CONTEXT_H_
 
 #include <vector>
+
 #include "webrtc/modules/desktop_capture/desktop_region.h"
 
 namespace webrtc {
 
 // A DxgiOutputContext stores the status of a single DxgiFrame of
 // DxgiOutputDuplicator.
 struct DxgiOutputContext final {
   // The updated region DxgiOutputDuplicator::DetectUpdatedRegion() output
   // during last Duplicate() function call. It's always relative to the (0, 0).
   DesktopRegion updated_region;
@@ skipping 27 matching lines @@
   // each DxgiDuplicatorController::Initialize().
   int controller_id = 0;
 
   // Child DxgiAdapterContext belongs to this DxgiFrameContext.
   std::vector<DxgiAdapterContext> contexts;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_CONTEXT_H_