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

jingle/notifier/base/gaia_token_pre_xmpp_auth.cc

 // Copyright (c) 2011 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 "jingle/notifier/base/gaia_token_pre_xmpp_auth.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/logging.h"
@@ skipping 83 matching lines @@
 std::string GaiaTokenPreXmppAuth::GetAuthToken() const {
   return token_;
 }
 
 std::string GaiaTokenPreXmppAuth::GetAuthMechanism() const {
   return auth_mechanism_;
 }
 
 std::string GaiaTokenPreXmppAuth::ChooseBestSaslMechanism(
     const std::vector<std::string> & mechanisms, bool encrypted) {
-  return (std::find(mechanisms.begin(),
-                    mechanisms.end(), auth_mechanism_) !=
-          mechanisms.end()) ? auth_mechanism_ : "";
+  return (std::find(mechanisms.begin(), mechanisms.end(), auth_mechanism_) !=
+              mechanisms.end())
+             ? auth_mechanism_
+             : std::string();
 }
 
 buzz::SaslMechanism* GaiaTokenPreXmppAuth::CreateSaslMechanism(
     const std::string& mechanism) {
   if (mechanism == auth_mechanism_)
     return new GaiaCookieMechanism(
         mechanism, username_, token_, token_service_);
   return NULL;
 }
 
 }  // namespace notifier