Replace NULL with nullptr in all C++ files.

webrtc/modules/desktop_capture/cropping_window_capturer_win.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 149 matching lines @@
       selected_window_rect.top,
       selected_window_rect.right,
       selected_window_rect.bottom);
 
   // Get the window region and check if it is rectangular.
   win::ScopedGDIObject<HRGN, win::DeleteObjectTraits<HRGN> >
       scoped_hrgn(CreateRectRgn(0, 0, 0, 0));
   int region_type = GetWindowRgn(selected, scoped_hrgn.Get());
 
   // Do not use the screen capturer if the region is empty or not rectangular.
-  if (region_type == COMPLEXREGION || region_type == NULLREGION)
+  if (region_type == COMPLEXREGION || region_type == nullptrREGION)
     return false;
 
   if (region_type == SIMPLEREGION) {
     RECT region_rect;
     GetRgnBox(scoped_hrgn.Get(), &region_rect);
     DesktopRect rgn_rect =
         DesktopRect::MakeLTRB(region_rect.left,
                               region_rect.top,
                               region_rect.right,
                               region_rect.bottom);
@@ skipping 29 matching lines @@
 }  // namespace
 
 // static
 std::unique_ptr<DesktopCapturer> CroppingWindowCapturer::CreateCapturer(
     const DesktopCaptureOptions& options) {
   return std::unique_ptr<DesktopCapturer>(
       new CroppingWindowCapturerWin(options));
 }
 
 }  // namespace webrtc