Allow Windows to return a monitor out of the first quadrant

webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc

 /*
  *  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 176 matching lines @@
     } else {
       const DesktopRect& left = desktop_rect_;
       const DesktopRect& right = duplicators_.back().desktop_rect();
       desktop_rect_ =
           DesktopRect::MakeLTRB(std::min(left.left(), right.left()),
                                 std::min(left.top(), right.top()),
                                 std::max(left.right(), right.right()),
                                 std::max(left.bottom(), right.bottom()));
     }
   }
+  TranslateRect();
 
   HDC hdc = GetDC(nullptr);
   // Use old DPI value if failed.
   if (hdc) {
     dpi_.set(GetDeviceCaps(hdc, LOGPIXELSX), GetDeviceCaps(hdc, LOGPIXELSY));
     ReleaseDC(nullptr, hdc);
   }
 
   identity_++;
   return true;
@@ skipping 81 matching lines @@
 int64_t DxgiDuplicatorController::GetNumFramesCaptured() const {
   int64_t min = INT64_MAX;
   for (const auto& duplicator : duplicators_) {
     min = std::min(min, duplicator.GetNumFramesCaptured());
   }
 
   return min;
 }
 
 DesktopSize DxgiDuplicatorController::desktop_size() const {
-  return DesktopSize(desktop_rect_.right(), desktop_rect_.bottom());
+  return desktop_rect_.size();
 }
 
 DesktopRect DxgiDuplicatorController::ScreenRect(int id) const {
   RTC_DCHECK(id >= 0);
   for (size_t i = 0; i < duplicators_.size(); i++) {
     if (id >= duplicators_[i].screen_count()) {
       id -= duplicators_[i].screen_count();
     } else {
       return duplicators_[i].ScreenRect(id);
     }
@@ skipping 62 matching lines @@
     if (!DoDuplicateAll(context, shared_frame)) {
       return false;
     }
     if (rtc::TimeMillis() - start_ms > timeout_ms) {
       return false;
     }
   }
   return true;
 }
 
+void DxgiDuplicatorController::TranslateRect() {
+  const DesktopVector position =
+      DesktopVector().subtract(desktop_rect_.top_left());
+  desktop_rect_.Translate(position);
+  for (auto& duplicator : duplicators_) {
+    duplicator.TranslateRect(position);
+  }
+}
+
 }  // namespace webrtc