Cleanup: Remove unneeded browser_thread.h usage.

chrome/browser/chromeos/login/mock_url_fetchers.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_MOCK_URL_FETCHERS_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_MOCK_URL_FETCHERS_H_
 #pragma once
 
+#include <string>
+
 #include "base/message_loop.h"
-#include "chrome/browser/browser_thread.h"
 #include "chrome/common/net/url_fetcher.h"
 #include "googleurl/src/gurl.h"
 #include "net/url_request/url_request_status.h"
 
 namespace chromeos {
 
 // Simulates a URL fetch by posting a delayed task.  This fetch expects to be
 // canceled, and fails the test if it is not
 class ExpectCanceledFetcher : public URLFetcher {
  public:
@@ skipping 78 matching lines @@
 
  private:
   GURL url_;
 
   DISALLOW_COPY_AND_ASSIGN(HostedFetcher);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_MOCK_URL_FETCHERS_H_