Add reference counter of DxgiDuplicatorController to unload DXGI components

webrtc/modules/desktop_capture/win/dxgi_context.cc

 /*
  *  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.
  */
 
 #include "webrtc/modules/desktop_capture/win/dxgi_context.h"
+
 #include "webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.h"
 
 namespace webrtc {
 
 DxgiAdapterContext::DxgiAdapterContext() = default;
 DxgiAdapterContext::DxgiAdapterContext(
     const DxgiAdapterContext& context) = default;
 DxgiAdapterContext::~DxgiAdapterContext() = default;
 
 DxgiFrameContext::DxgiFrameContext() = default;
 
 DxgiFrameContext::~DxgiFrameContext() {
-  DxgiDuplicatorController::Instance()->Unregister(this);
+  DxgiDuplicatorController::GetReference()->Unregister(this);
 }
 
 void DxgiFrameContext::Reset() {
   controller_id = 0;
 }
 
 }  // namespace webrtc