Allow Windows to return a monitor out of the first quadrant

webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.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.
  */
 
 #include "webrtc/modules/desktop_capture/win/dxgi_adapter_duplicator.h"
 
 #include <comdef.h>
 #include <DXGI.h>
 
 #include <algorithm>
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/logging.h"
 
 namespace webrtc {
 
 using Microsoft::WRL::ComPtr;
 
 namespace {
 
 bool IsValidRect(const RECT& rect) {
-  return rect.left >= 0 && rect.top >= 0 && rect.right > rect.left &&
-         rect.bottom > rect.top;
+  return rect.right > rect.left && rect.bottom > rect.top;
 }
 
 }  // namespace
 
 DxgiAdapterDuplicator::DxgiAdapterDuplicator(const D3dDevice& device)
     : device_(device) {}
 DxgiAdapterDuplicator::DxgiAdapterDuplicator(DxgiAdapterDuplicator&&) = default;
 DxgiAdapterDuplicator::~DxgiAdapterDuplicator() = default;
 
 bool DxgiAdapterDuplicator::Initialize() {
@@ skipping 106 matching lines @@
 
 int64_t DxgiAdapterDuplicator::GetNumFramesCaptured() const {
   int64_t min = INT64_MAX;
   for (const auto& duplicator : duplicators_) {
     min = std::min(min, duplicator.num_frames_captured());
   }
 
   return min;
 }
 
+void DxgiAdapterDuplicator::TranslateRect(const DesktopVector& position) {
+  desktop_rect_.Translate(position);
+  RTC_DCHECK(desktop_rect_.left() >= 0 && desktop_rect_.top() >= 0);
+  for (auto& duplicator : duplicators_) {
+    duplicator.TranslateRect(position);
+  }
+}
+
 }  // namespace webrtc