C++11 declares a type safe null pointer

content/common/gpu/image_transport_surface_iosurface_mac.cc

 // Copyright 2014 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 "content/common/gpu/image_transport_surface_iosurface_mac.h"
 
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/gpu/surface_handle_types_mac.h"
 
 namespace content {
@@ skipping 16 matching lines @@
                      const CFStringRef key,
                      bool value) {
   CFDictionaryAddValue(dictionary, key,
                        (value ? kCFBooleanTrue : kCFBooleanFalse));
 }
 
 void AddIntegerValue(CFMutableDictionaryRef dictionary,
                      const CFStringRef key,
                      int32 value) {
   base::ScopedCFTypeRef<CFNumberRef> number(
-      CFNumberCreate(NULL, kCFNumberSInt32Type, &value));
+      CFNumberCreate(nullptr, kCFNumberSInt32Type, &value));
   CFDictionaryAddValue(dictionary, key, number.get());
 }
 
 }  // namespace
 
 IOSurfaceStorageProvider::IOSurfaceStorageProvider(
     ImageTransportSurfaceFBO* transport_surface)
         : transport_surface_(transport_surface) {}
 
 IOSurfaceStorageProvider::~IOSurfaceStorageProvider() {
@@ skipping 76 matching lines @@
 void IOSurfaceStorageProvider::DiscardBackbuffer() {
 }
 
 void IOSurfaceStorageProvider::SwapBuffersAckedByBrowser(
     bool disable_throttling) {
   DCHECK(!pending_swapped_surfaces_.empty());
   pending_swapped_surfaces_.pop_front();
 }
 
 }  //  namespace content