ui: Cleanup class/struct forward declarations

ui/base/ime/chromeos/input_method_manager.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 UI_BASE_IME_CHROMEOS_INPUT_METHOD_MANAGER_H_
 #define UI_BASE_IME_CHROMEOS_INPUT_METHOD_MANAGER_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "ui/base/ime/chromeos/input_method_descriptor.h"
 #include "ui/base/ime/ui_base_ime_export.h"
 
 class Profile;
 
 namespace ui {
 class Accelerator;
 class IMEEngineHandlerInterface;
 }  // namespace ui
 
-namespace user_manager {
-class User;
-}  // namespace user_manager
-
 namespace chromeos {
 class ComponentExtensionIMEManager;
 namespace input_method {
 class InputMethodUtil;
 class ImeKeyboard;
 
 // This class manages input methodshandles.  Classes can add themselves as
 // observers. Clients can get an instance of this library class by:
 // InputMethodManager::Get().
 class UI_BASE_IME_EXPORT InputMethodManager {
@@ skipping 271 matching lines @@
 
   // Returns whether the extra inputs: emoji, handwriting and voice inputs on
   // opt-in IME menu has been enabled.
   virtual bool IsEmojiHandwritingVoiceOnImeMenuEnabled() = 0;
 };
 
 }  // namespace input_method
 }  // namespace chromeos
 
 #endif  // UI_BASE_IME_CHROMEOS_INPUT_METHOD_MANAGER_H_