Rewrite scoped_ptr<T>(NULL) to use the default ctor in chrome/.

chrome/browser/extensions/extension_function.cc

 // 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 "chrome/browser/extensions/extension_function.h"
 
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/extensions/extension_function_dispatcher.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 37 matching lines @@
     const IPC::Message& message) {
   return function_->OnMessageReceivedFromRenderView(message);
 }
 
 ExtensionFunction::ExtensionFunction()
     : request_id_(-1),
       profile_id_(NULL),
       has_callback_(false),
       include_incognito_(false),
       user_gesture_(false),
-      args_(NULL),
       bad_message_(false),
-      histogram_value_(extensions::functions::UNKNOWN) {
-}
+      histogram_value_(extensions::functions::UNKNOWN) {}
 
 ExtensionFunction::~ExtensionFunction() {
 }
 
 UIThreadExtensionFunction* ExtensionFunction::AsUIThreadExtensionFunction() {
   return NULL;
 }
 
 IOThreadExtensionFunction* ExtensionFunction::AsIOThreadExtensionFunction() {
   return NULL;
@@ skipping 230 matching lines @@
 
 SyncIOThreadExtensionFunction::SyncIOThreadExtensionFunction() {
 }
 
 SyncIOThreadExtensionFunction::~SyncIOThreadExtensionFunction() {
 }
 
 void SyncIOThreadExtensionFunction::Run() {
   SendResponse(RunImpl());
 }