Remove header dependencies from sequence_checker.h to sequenced_worker_pool.h

ui/base/ime/input_method_chromeos.h

 // Copyright 2014 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 UI_BASE_IME_INPUT_METHOD_CHROMEOS_H_
 #define UI_BASE_IME_INPUT_METHOD_CHROMEOS_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <set>
 #include <string>
 
+#include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "ui/base/ime/chromeos/character_composer.h"
 #include "ui/base/ime/composition_text.h"
 #include "ui/base/ime/ime_input_context_handler_interface.h"
 #include "ui/base/ime/input_method_base.h"
 
 namespace ui {
 
@@ skipping 119 matching lines @@
 
   // Used for making callbacks.
   base::WeakPtrFactory<InputMethodChromeOS> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(InputMethodChromeOS);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_IME_INPUT_METHOD_CHROMEOS_H_