Fix ScreenCapturerWinGdi to handle DesktopFrameWin::Create() errors.

webrtc/modules/desktop_capture/win/screen_capturer_win_gdi.cc

 /*
  *  Copyright (c) 2014 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 223 matching lines @@
   // may still be reading from them.
   if (!queue_.current_frame() ||
       !queue_.current_frame()->size().equals(screen_rect.size())) {
     assert(desktop_dc_ != NULL);
     assert(memory_dc_ != NULL);
 
     size_t buffer_size = size.width() * size.height() *
         DesktopFrame::kBytesPerPixel;
     SharedMemory* shared_memory = callback_->CreateSharedMemory(buffer_size);
 
-    rtc::scoped_ptr<DesktopFrame> buffer;
-    buffer.reset(
+    rtc::scoped_ptr<DesktopFrame> buffer(
         DesktopFrameWin::Create(size, shared_memory, desktop_dc_));
+    if (!buffer.get())
+      return false;
     queue_.ReplaceCurrentFrame(buffer.release());
   }
 
   // Select the target bitmap into the memory dc and copy the rect from desktop
   // to memory.
   DesktopFrameWin* current = static_cast<DesktopFrameWin*>(
       queue_.current_frame()->GetUnderlyingFrame());
   HGDIOBJ previous_object = SelectObject(memory_dc_, current->bitmap());
   if (previous_object != NULL) {
     BitBlt(memory_dc_,
            0, 0, screen_rect.width(), screen_rect.height(),
            desktop_dc_,
            screen_rect.left(), screen_rect.top(),
            SRCCOPY | CAPTUREBLT);
 
     // Select back the previously selected object to that the device contect
     // could be destroyed independently of the bitmap if needed.
     SelectObject(memory_dc_, previous_object);
   }
   return true;
 }
 
 }  // namespace webrtc