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

chrome/browser/signin/signin_manager_factory.cc

Index: chrome/browser/signin/signin_manager_factory.cc
diff --git a/chrome/browser/signin/signin_manager_factory.cc b/chrome/browser/signin/signin_manager_factory.cc
index 67e33c07dc9b7ec18e4c4ee86afd54ac215918b8..11dd5e694039cc370c5c28239e128494b6b951ec 100644
--- a/chrome/browser/signin/signin_manager_factory.cc
+++ b/chrome/browser/signin/signin_manager_factory.cc
@@ -39,9 +39,11 @@ SigninManagerFactory* SigninManagerFactory::GetInstance() {
 }
 
 void SigninManagerFactory::RegisterUserPrefs(PrefRegistrySyncable* registry) {
-  registry->RegisterStringPref(prefs::kGoogleServicesLastUsername, "",
+  registry->RegisterStringPref(prefs::kGoogleServicesLastUsername,
+                               std::string(),
                                PrefRegistrySyncable::UNSYNCABLE_PREF);
-  registry->RegisterStringPref(prefs::kGoogleServicesUsername, "",
+  registry->RegisterStringPref(prefs::kGoogleServicesUsername,
+                               std::string(),
                                PrefRegistrySyncable::UNSYNCABLE_PREF);
   registry->RegisterBooleanPref(prefs::kAutologinEnabled, true,
                                 PrefRegistrySyncable::UNSYNCABLE_PREF);
@@ -54,7 +56,8 @@ void SigninManagerFactory::RegisterUserPrefs(PrefRegistrySyncable* registry) {
 
 // static
 void SigninManagerFactory::RegisterPrefs(PrefRegistrySimple* registry) {
-  registry->RegisterStringPref(prefs::kGoogleServicesUsernamePattern, "");
+  registry->RegisterStringPref(prefs::kGoogleServicesUsernamePattern,
+                               std::string());
 }
 
 ProfileKeyedService* SigninManagerFactory::BuildServiceInstanceFor(