Allow Windows to return a monitor out of the first quadrant

webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h

Index: webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h
diff --git a/webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h b/webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h
index 4aee8b85b02c1263e1c8d5ac8d69911de22bae24..bbfb8ff25c8d0140219260c16742d30e5c08516e 100644
--- a/webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h
+++ b/webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h
@@ -71,6 +71,10 @@ class DxgiAdapterDuplicator {
   // The minimum num_frames_captured() returned by |duplicators_|.
   int64_t GetNumFramesCaptured() const;
 
+  // Moves |desktop_rect_| and all underlying |duplicators_|. See
+  // DxgiDuplicatorController::Translate().
+  void Translate(int32_t dx, int32_t dy);
+
  private:
   bool DoInitialize();