Update XServerPixelBuffer to handle errors returned from XGetImage().

webrtc/modules/desktop_capture/window_capturer_x11.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 275 matching lines @@
     // something we want so instead, just bail out.
     LOG(LS_INFO) << "No Xcomposite extension detected.";
     callback_->OnCaptureResult(Result::ERROR_PERMANENT, nullptr);
     return;
   }
 
   std::unique_ptr<DesktopFrame> frame(
       new BasicDesktopFrame(x_server_pixel_buffer_.window_size()));
 
   x_server_pixel_buffer_.Synchronize();
-  x_server_pixel_buffer_.CaptureRect(DesktopRect::MakeSize(frame->size()),
-                                     frame.get());
+  if (!x_server_pixel_buffer_.CaptureRect(DesktopRect::MakeSize(frame->size()),
+                                          frame.get())) {
+    callback_->OnCaptureResult(Result::ERROR_TEMPORARY, nullptr);
+    return;
+  }
 
   frame->mutable_updated_region()->SetRect(
       DesktopRect::MakeSize(frame->size()));
 
   callback_->OnCaptureResult(Result::SUCCESS, std::move(frame));
 }
 
 bool WindowCapturerLinux::HandleXEvent(const XEvent& event) {
   if (event.type == ConfigureNotify) {
     XConfigureEvent xce = event.xconfigure;
@@ skipping 113 matching lines @@
 }  // namespace
 
 // static
 WindowCapturer* WindowCapturer::Create(const DesktopCaptureOptions& options) {
   if (!options.x_display())
     return nullptr;
   return new WindowCapturerLinux(options);
 }
 
 }  // namespace webrtc