FBTF: Remove "obviously" unneeded standard C++ library #includes.

chrome/browser/history/in_memory_history_backend.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.
 
 // Contains the history backend wrapper around the in-memory URL database. This
 // object maintains an in-memory cache of the subset of history required to do
 // in-line autocomplete.
 //
 // It is created on the history thread and passed to the main thread where
 // operations can be completed synchronously. It listenes for notifications
 // from the "regular" history backend and keeps itself in sync.
 
 #ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_
 #define CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_
 #pragma once
 
-#include <string>
-
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/scoped_ptr.h"
 #include "chrome/common/notification_registrar.h"
 
 class FilePath;
 class HistoryDatabase;
 class Profile;
 
 namespace history {
@@ skipping 53 matching lines @@
   // The profile that this object is attached. May be NULL before
   // initialization.
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(InMemoryHistoryBackend);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_IN_MEMORY_HISTORY_BACKEND_H_