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

chrome/browser/browsing_data/browsing_data_database_helper_unittest.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/browsing_data/browsing_data_database_helper.h"
 
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/test/test_browser_thread.h"
@@ skipping 17 matching lines @@
 TEST_F(CannedBrowsingDataDatabaseHelperTest, Empty) {
   TestingProfile profile;
 
   const GURL origin("http://host1:1/");
   const char db[] = "db1";
 
   scoped_refptr<CannedBrowsingDataDatabaseHelper> helper(
       new CannedBrowsingDataDatabaseHelper(&profile));
 
   ASSERT_TRUE(helper->empty());
-  helper->AddDatabase(origin, db, "");
+  helper->AddDatabase(origin, db, std::string());
   ASSERT_FALSE(helper->empty());
   helper->Reset();
   ASSERT_TRUE(helper->empty());
 }
 
 TEST_F(CannedBrowsingDataDatabaseHelperTest, IgnoreExtensionsAndDevTools) {
   TestingProfile profile;
 
   const GURL origin1("chrome-extension://abcdefghijklmnopqrstuvwxyz/");
   const GURL origin2("chrome-devtools://abcdefghijklmnopqrstuvwxyz/");
   const char db[] = "db1";
 
   scoped_refptr<CannedBrowsingDataDatabaseHelper> helper(
       new CannedBrowsingDataDatabaseHelper(&profile));
 
   ASSERT_TRUE(helper->empty());
-  helper->AddDatabase(origin1, db, "");
+  helper->AddDatabase(origin1, db, std::string());
   ASSERT_TRUE(helper->empty());
-  helper->AddDatabase(origin2, db, "");
+  helper->AddDatabase(origin2, db, std::string());
   ASSERT_TRUE(helper->empty());
   helper->Reset();
   ASSERT_TRUE(helper->empty());
 }
 
 }  // namespace