Allow Windows to return a monitor out of the first quadrant

webrtc/modules/desktop_capture/win/dxgi_output_duplicator.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 57 matching lines @@
   // Returns the desktop rect covered by this DxgiOutputDuplicator.
   DesktopRect desktop_rect() const { return desktop_rect_; }
 
   void Setup(Context* context);
 
   void Unregister(const Context* const context);
 
   // How many frames have been captured by this DxigOutputDuplicator.
   int64_t num_frames_captured() const;
 
+  // Moves |desktop_rect_|. See DxgiDuplicatorController::TranslateRect().
+  void TranslateRect(const DesktopVector& position);
+
  private:
   // Calls DoDetectUpdatedRegion(). If it fails, this function sets the
   // |updated_region| as entire UntranslatedDesktopRect().
   void DetectUpdatedRegion(const DXGI_OUTDUPL_FRAME_INFO& frame_info,
                            DesktopRegion* updated_region);
 
   // Returns untranslated updated region, which are directly returned by Windows
   // APIs. Returns false in case of a failure.
   bool DoDetectUpdatedRegion(const DXGI_OUTDUPL_FRAME_INFO& frame_info,
                              DesktopRegion* updated_region);
@@ skipping 14 matching lines @@
 
   // Spreads changes from |context| to other registered Context(s) in
   // contexts_.
   void SpreadContextChange(const Context* const context);
 
   // Returns the size of desktop rectangle current instance representing.
   DesktopSize desktop_size() const;
 
   const D3dDevice device_;
   const Microsoft::WRL::ComPtr<IDXGIOutput1> output_;
-  const DesktopRect desktop_rect_;
+  DesktopRect desktop_rect_;
   Microsoft::WRL::ComPtr<IDXGIOutputDuplication> duplication_;
   DXGI_OUTDUPL_DESC desc_;
   std::vector<uint8_t> metadata_;
   std::unique_ptr<DxgiTexture> texture_;
   Rotation rotation_;
   DesktopSize unrotated_size_;
 
   // After each AcquireNextFrame() function call, updated_region_(s) of all
   // active Context(s) need to be updated. Since they have missed the
   // change this time. And during next Duplicate() function call, their
   // updated_region_ will be merged and copied.
   std::vector<Context*> contexts_;
 
   // The last full frame of this output and its offset. If on AcquireNextFrame()
   // failed because of timeout, i.e. no update, we can copy content from
   // |last_frame_|.
   std::unique_ptr<SharedDesktopFrame> last_frame_;
   DesktopVector last_frame_offset_;
 
   int64_t num_frames_captured_ = 0;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_DESKTOP_CAPTURE_WIN_DXGI_OUTPUT_DUPLICATOR_H_