Cleanup: IWYU for BrowserThread.

content/public/browser/browser_thread.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_
 #define CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_
 #pragma once
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "base/location.h"
 #include "base/message_loop_proxy.h"
-#include "base/tracked_objects.h"
+#include "base/time.h"
 #include "content/common/content_export.h"
-#include "content/public/browser/browser_thread_delegate.h"
 
 #if defined(UNIT_TEST)
 #include "base/logging.h"
 #endif  // UNIT_TEST
 
 class MessageLoop;
 
 namespace base {
 class SequencedWorkerPool;
 class Thread;
 }
 
 namespace content {
 
+class BrowserThreadDelegate;
 class BrowserThreadImpl;
 
 ///////////////////////////////////////////////////////////////////////////////
 // BrowserThread
 //
 // Utility functions for threads that are known by a browser-wide
 // name.  For example, there is one IO thread for the entire browser
 // process, and various pieces of code find it useful to retrieve a
 // pointer to the IO thread's message loop.
 //
@@ skipping 223 matching lines @@
  private:
   friend class BrowserThreadImpl;
 
   BrowserThread() {}
   DISALLOW_COPY_AND_ASSIGN(BrowserThread);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_BROWSER_THREAD_H_