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

chrome/browser/google_apis/gdata_wapi_service.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/google_apis/gdata_wapi_service.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 80 matching lines @@
   callback.Run(error, app_list.Pass());
 }
 
 }  // namespace
 
 GDataWapiService::GDataWapiService(
     net::URLRequestContextGetter* url_request_context_getter,
     const GURL& base_url,
     const std::string& custom_user_agent)
     : url_request_context_getter_(url_request_context_getter),
-      sender_(NULL),
       url_generator_(base_url),
       custom_user_agent_(custom_user_agent) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
 GDataWapiService::~GDataWapiService() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (sender_.get())
     sender_->auth_service()->RemoveObserver(this);
 }
@@ skipping 487 matching lines @@
   if (CanSendRequest()) {
     FOR_EACH_OBSERVER(
         DriveServiceObserver, observers_, OnReadyToSendRequests());
   } else if (!HasRefreshToken()) {
     FOR_EACH_OBSERVER(
         DriveServiceObserver, observers_, OnRefreshTokenInvalid());
   }
 }
 
 }  // namespace google_apis