[WebRTC] A real ScreenCapturer test

webrtc/modules/desktop_capture/desktop_frame.cc

 /*
  *  Copyright (c) 2013 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 39 matching lines @@
       DesktopRect::MakeOriginSize(src_pos, dest_rect.size())));
 
   CopyPixelsFrom(src_frame.GetFrameDataAtPos(src_pos),
                  src_frame.stride(), dest_rect);
 }
 
 uint8_t* DesktopFrame::GetFrameDataAtPos(const DesktopVector& pos) const {
   return data() + stride() * pos.y() + DesktopFrame::kBytesPerPixel * pos.x();
 }
 
+DesktopVector DesktopFrame::GetPosAtFrameData(const uint8_t* const pos) const {
+  return DesktopVector((pos - data()) % stride() / DesktopFrame::kBytesPerPixel,
+                       (pos - data()) / stride());
+}
+
 BasicDesktopFrame::BasicDesktopFrame(DesktopSize size)
     : DesktopFrame(size, kBytesPerPixel * size.width(),
                    new uint8_t[kBytesPerPixel * size.width() * size.height()],
                    NULL) {
 }
 
 BasicDesktopFrame::~BasicDesktopFrame() {
   delete[] data_;
 }
 
@@ skipping 39 matching lines @@
     : DesktopFrame(size,
                    stride,
                    reinterpret_cast<uint8_t*>(shared_memory->data()),
                    shared_memory) {}
 
 SharedMemoryDesktopFrame::~SharedMemoryDesktopFrame() {
   delete shared_memory_;
 }
 
 }  // namespace webrtc