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

remoting/host/setup/oauth_helper.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 "remoting/host/setup/oauth_helper.h"
 
 #include "base/stringprintf.h"
 #include "google_apis/google_api_keys.h"
 #include "googleurl/src/url_parse.h"
 #include "net/base/escape.h"
 
 namespace {
 
 std::string GetComponent(const std::string& url,
                          const url_parse::Component component) {
   if (component.len < 0) {
-    return "";
+    return std::string();
   }
   return url.substr(component.begin, component.len);
 }
 
 }  // namespace
 
 namespace remoting {
 
 std::string GetOauthScope() {
   return
@@ skipping 25 matching lines @@
 
 std::string GetOauthCodeInUrl(const std::string& url,
                               const std::string& redirect_url) {
   url_parse::Parsed url_parsed;
   ParseStandardURL(url.c_str(), url.length(), &url_parsed);
   url_parse::Parsed redirect_url_parsed;
   ParseStandardURL(redirect_url.c_str(), redirect_url.length(),
                    &redirect_url_parsed);
   if (GetComponent(url, url_parsed.scheme) !=
       GetComponent(redirect_url, redirect_url_parsed.scheme)) {
-    return "";
+    return std::string();
   }
   if (GetComponent(url, url_parsed.host) !=
       GetComponent(redirect_url, redirect_url_parsed.host)) {
-    return "";
+    return std::string();
   }
   url_parse::Component query = url_parsed.query;
   url_parse::Component key;
   url_parse::Component value;
   while (ExtractQueryKeyValue(url.c_str(), &query, &key, &value)) {
     if (GetComponent(url, key) == "code") {
       return GetComponent(url, value);
     }
   }
-  return "";
+  return std::string();
 }
 
 }  // namespace remoting