Fixed window capute may end when window's full screen mode switchs on/off

webrtc/modules/desktop_capture/window_capturer_win.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 138 matching lines @@
   callback_ = callback;
 }
 
 void WindowCapturerWin::Capture(const DesktopRegion& region) {
   if (!window_) {
     LOG(LS_ERROR) << "Window hasn't been selected: " << GetLastError();
     callback_->OnCaptureCompleted(NULL);
     return;
   }
 
-  // Stop capturing if the window has been closed or hidden.
-  if (!IsWindow(window_) || !IsWindowVisible(window_)) {
+  // Stop capturing if the window has been closed.
+  if (!IsWindow(window_)) {
     callback_->OnCaptureCompleted(NULL);
     return;
   }
 
-  // Return a 1x1 black frame if the window is minimized, to match the behavior
-  // on Mac.
-  if (IsIconic(window_)) {
+  // Return a 1x1 black frame if the window is minimized or invisible, to match
+  // behavior on mace. Window can be temporarily invisible during the
+  // transition of full screen mode on/off.
+  if (IsIconic(window_) || !IsWindowVisible(window_)) {
     BasicDesktopFrame* frame = new BasicDesktopFrame(DesktopSize(1, 1));
     memset(frame->data(), 0, frame->stride() * frame->size().height());
 
     previous_size_ = frame->size();
     callback_->OnCaptureCompleted(frame);
     return;
   }
 
   DesktopRect original_rect;
   DesktopRect cropped_rect;
@@ skipping 70 matching lines @@
 }
 
 }  // namespace
 
 // static
 WindowCapturer* WindowCapturer::Create(const DesktopCaptureOptions& options) {
   return new WindowCapturerWin();
 }
 
 }  // namespace webrtc