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

chrome/browser/profiles/gaia_info_update_service_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/profiles/gaia_info_update_service.h"
 
 #include "base/prefs/pref_service.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile_downloader.h"
@@ skipping 166 matching lines @@
   gfx::Image gaia_picture = gfx::test::CreateImage();
   GetCache()->SetGAIAPictureOfProfileAtIndex(0, &gaia_picture);
 
   // Set a fake picture URL.
   profile()->GetPrefs()->SetString(prefs::kProfileGAIAInfoPictureURL,
                                    "example.com");
 
   GAIAInfoUpdateService service(profile());
   EXPECT_FALSE(service.GetCachedPictureURL().empty());
   // Log out.
-  profile()->GetPrefs()->SetString(prefs::kGoogleServicesUsername, "");
+  profile()->GetPrefs()
+      ->SetString(prefs::kGoogleServicesUsername, std::string());
 
   // Verify that the GAIA name and picture, and picture URL are unset.
   EXPECT_TRUE(GetCache()->GetGAIANameOfProfileAtIndex(0).empty());
   EXPECT_EQ(NULL, GetCache()->GetGAIAPictureOfProfileAtIndex(0));
   EXPECT_TRUE(service.GetCachedPictureURL().empty());
 }
 
 TEST_F(GAIAInfoUpdateServiceTest, LogIn) {
-  profile()->GetPrefs()->SetString(prefs::kGoogleServicesUsername, "");
+  profile()->GetPrefs()
+      ->SetString(prefs::kGoogleServicesUsername, std::string());
   GAIAInfoUpdateServiceMock service(profile());
 
   // Log in.
   EXPECT_CALL(service, Update());
   profile()->GetPrefs()->SetString(prefs::kGoogleServicesUsername,
                                    "pat@example.com");
 }