Use a direct include of strings headers in chrome/browser/r*-s*/.

chrome/browser/signin/signin_manager_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/signin/signin_manager.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/testing_pref_service.h"
-#include "base/stringprintf.h"
+#include "base/strings/stringprintf.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/prefs/browser_prefs.h"
 #include "chrome/browser/signin/chrome_signin_manager_delegate.h"
 #include "chrome/browser/signin/token_service.h"
 #include "chrome/browser/signin/token_service_unittest.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
@@ skipping 628 matching lines @@
 TEST_F(SigninManagerTest, ProhibitedAfterStartup) {
   std::string user("monkey@invalid.com");
   profile_->GetPrefs()->SetString(prefs::kGoogleServicesUsername, user);
   manager_->Initialize(profile_.get(), g_browser_process->local_state());
   EXPECT_EQ(user, manager_->GetAuthenticatedUsername());
   // Update the profile - user should be signed out.
   g_browser_process->local_state()->SetString(
       prefs::kGoogleServicesUsernamePattern, ".*@google.com");
   EXPECT_EQ("", manager_->GetAuthenticatedUsername());
 }