C++11 declares a type safe null pointer

content/common/input/touch_event_stream_validator.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/input/touch_event_stream_validator.h"
 
 #include "base/logging.h"
 #include "content/common/input/web_touch_event_traits.h"
 
 using blink::WebInputEvent;
 using blink::WebTouchEvent;
 using blink::WebTouchPoint;
 
 namespace content {
 namespace {
 
 const WebTouchPoint* FindTouchPoint(const WebTouchEvent& event, int id) {
   for (unsigned i = 0; i < event.touchesLength; ++i) {
     if (event.touches[i].id == id)
       return &event.touches[i];
   }
-  return NULL;
+  return nullptr;
 }
 
 }  // namespace
 
 TouchEventStreamValidator::TouchEventStreamValidator() {
 }
 
 TouchEventStreamValidator::~TouchEventStreamValidator() {
 }
 
@@ skipping 87 matching lines @@
     }
   }
 
   if (!found_valid_state_for_type)
     error_msg->append("No valid touch point corresponding to event type.");
 
   return error_msg->empty();
 }
 
 }  // namespace content