Rewrite std::string("") to std::string(), Linux edition.

chrome/browser/profiles/gaia_info_update_service_factory.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/profiles/gaia_info_update_service_factory.h"
 
 #include "chrome/browser/profiles/gaia_info_update_service.h"
 #include "chrome/browser/profiles/profile_dependency_manager.h"
 #include "chrome/common/pref_names.h"
 #include "components/user_prefs/pref_registry_syncable.h"
@@ skipping 21 matching lines @@
     Profile* profile) const {
   if (!GAIAInfoUpdateService::ShouldUseGAIAProfileInfo(profile))
     return NULL;
   return new GAIAInfoUpdateService(profile);
 }
 
 void GAIAInfoUpdateServiceFactory::RegisterUserPrefs(
     PrefRegistrySyncable* prefs) {
   prefs->RegisterInt64Pref(prefs::kProfileGAIAInfoUpdateTime, 0,
                            PrefRegistrySyncable::UNSYNCABLE_PREF);
-  prefs->RegisterStringPref(prefs::kProfileGAIAInfoPictureURL, "",
+  prefs->RegisterStringPref(prefs::kProfileGAIAInfoPictureURL,
+                            std::string(),
                             PrefRegistrySyncable::UNSYNCABLE_PREF);
 }
 
 bool GAIAInfoUpdateServiceFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }