Run clang-modernize -use-nullptr over src/extensions/.

extensions/renderer/i18n_custom_bindings.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 "extensions/renderer/i18n_custom_bindings.h"
 
 #include "base/bind.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/public/renderer/render_view.h"
 #include "extensions/common/extension_messages.h"
@@ skipping 66 matching lines @@
           *v8::String::Utf8Value(
               placeholders->Get(v8::Integer::New(isolate, i))->ToString()));
     }
   } else if (args[1]->IsString()) {
     // chrome.i18n.getMessage("message_name", "one param");
     substitutions.push_back(*v8::String::Utf8Value(args[1]->ToString()));
   }
 
   args.GetReturnValue().Set(v8::String::NewFromUtf8(
       isolate,
-      ReplaceStringPlaceholders(message, substitutions, NULL).c_str()));
+      ReplaceStringPlaceholders(message, substitutions, nullptr).c_str()));
 }
 
 void I18NCustomBindings::GetL10nUILanguage(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   args.GetReturnValue().Set(v8::String::NewFromUtf8(
       args.GetIsolate(), content::RenderThread::Get()->GetLocale().c_str()));
 }
 
 }  // namespace extensions