ScreenCapturerWinDirectx flickers in Desktop Capturer Sample

webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h

 /*
  *  Copyright (c) 2016 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 41 matching lines @@
   void SetSharedMemoryFactory(
       std::unique_ptr<SharedMemoryFactory> shared_memory_factory) override;
   void CaptureFrame() override;
   bool GetSourceList(SourceList* sources) override;
   bool SelectSource(SourceId id) override;
 
  private:
   // Returns desktop size of selected screen.
   DesktopSize SelectedDesktopSize() const;
 
+  // TODO(zijiehe): Merge |frames_| and |contexts_| into a single object.
   ScreenCaptureFrameQueue<SharedDesktopFrame> frames_;
+  ScreenCaptureFrameQueue<DxgiDuplicatorController::Context> contexts_;
   std::unique_ptr<SharedMemoryFactory> shared_memory_factory_;
   Callback* callback_ = nullptr;
-  DxgiDuplicatorController::Context context_;
   SourceId current_screen_id_ = kFullDesktopScreenId;
   ResolutionChangeDetector resolution_change_detector_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(ScreenCapturerWinDirectx);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_SCREEN_CAPTURER_WIN_DIRECTX_H_