replace NULL->nullptr in src/remoting.

remoting/host/desktop_shape_tracker_win.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/desktop_shape_tracker.h"
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/win/scoped_gdi_object.h"
@@ skipping 49 matching lines @@
     PLOG(ERROR) << "Failed to enumerate windows";
     desktop_shape_.Clear();
     return;
   }
 
   // If the shape has changed, refresh |desktop_shape_|.
   if (!EqualRgn(shape_data->desktop_region, old_desktop_region_)) {
     old_desktop_region_.Set(shape_data->desktop_region.release());
 
     // Determine the size of output buffer required to receive the region.
-    DWORD bytes_size = GetRegionData(old_desktop_region_, 0, NULL);
+    DWORD bytes_size = GetRegionData(old_desktop_region_, 0, nullptr);
     CHECK(bytes_size != 0);
 
     // Fetch the Windows RECTs that comprise the region.
     std::vector<char> buffer(bytes_size);
     LPRGNDATA region_data = reinterpret_cast<LPRGNDATA>(buffer.data());
     DWORD result = GetRegionData(old_desktop_region_, bytes_size, region_data);
     CHECK(result == bytes_size);
     const LPRECT rects = reinterpret_cast<LPRECT>(&region_data->Buffer[0]);
 
     // Reset |desktop_shape_| and add new rectangles into it.
@@ skipping 51 matching lines @@
 
 } // namespace
 
 // static
 scoped_ptr<DesktopShapeTracker> DesktopShapeTracker::Create(
     webrtc::DesktopCaptureOptions options) {
   return make_scoped_ptr(new DesktopShapeTrackerWin());
 }
 
 }  // namespace remoting