Allow Windows to return a monitor out of the first quadrant

webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc

Index: webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc
diff --git a/webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc b/webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc
index 12876c2c89d4612731de10c6e1ba51932f1d8003..576267bbfa6ce93d116de984a6d15b9faec93db1 100644
--- a/webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc
+++ b/webrtc/modules/desktop_capture/win/dxgi_duplicator_controller.cc
@@ -194,6 +194,7 @@ bool DxgiDuplicatorController::DoInitialize() {
                                 std::max(left.bottom(), right.bottom()));
     }
   }
+  TranslateRect();
 
   HDC hdc = GetDC(nullptr);
   // Use old DPI value if failed.
@@ -295,7 +296,7 @@ int64_t DxgiDuplicatorController::GetNumFramesCaptured() const {
 }
 
 DesktopSize DxgiDuplicatorController::desktop_size() const {
-  return DesktopSize(desktop_rect_.right(), desktop_rect_.bottom());
+  return desktop_rect_.size();
 }
 
 DesktopRect DxgiDuplicatorController::ScreenRect(int id) const {
@@ -378,4 +379,13 @@ bool DxgiDuplicatorController::EnsureFrameCaptured(Context* context,
   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