[C++11 Allowed Features] Declares a type-safe null pointer converting from NULL to nullptr

content/browser/accessibility/accessibility_tree_formatter_mac.mm

 // Copyright (c) 2012 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/browser/accessibility/accessibility_tree_formatter.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
@@ skipping 244 matching lines @@
       std::string json_value;
       base::JSONWriter::Write(value, &json_value);
       WriteAttribute(
           [defaultAttributes containsObject:requestedAttribute],
           StringPrintf("%s=%s",
                        requestedAttributeUTF8.c_str(),
                        json_value.c_str()),
           &line);
     }
   }
-  const base::DictionaryValue* d_value = NULL;
+  const base::DictionaryValue* d_value = nullptr;
   if (dict.GetDictionary(kPositionDictAttr, &d_value)) {
     WriteAttribute(false,
                    FormatCoordinates(kPositionDictAttr,
                                      kXCoordDictAttr, kYCoordDictAttr,
                                      *d_value),
                    &line);
   }
   if (dict.GetDictionary(kSizeDictAttr, &d_value)) {
     WriteAttribute(false,
                    FormatCoordinates(kSizeDictAttr,
@@ skipping 25 matching lines @@
 const string AccessibilityTreeFormatter::GetAllowString() {
   return "@MAC-ALLOW:";
 }
 
 // static
 const string AccessibilityTreeFormatter::GetDenyString() {
   return "@MAC-DENY:";
 }
 
 }  // namespace content