[Code cleanup]Remove webui virtual keyboard code

ui/keyboard/keyboard_ui_controller.h

-// Copyright (c) 2013 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_KEYBOARD_KEYBOARD_UI_CONTROLLER_H_
-#define UI_KEYBOARD_KEYBOARD_UI_CONTROLLER_H_
-
-#include "content/public/browser/web_ui_controller.h"
-#include "ui/keyboard/keyboard_export.h"
-
-namespace content {
-class WebUI;
-};
-
-namespace keyboard {
-
-// WebUIController for chrome://keyboard/.
-class KEYBOARD_EXPORT KeyboardUIController : public content::WebUIController {
- public:
-  explicit KeyboardUIController(content::WebUI* web_ui);
-  virtual ~KeyboardUIController();
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(KeyboardUIController);
-};
-
-}  // namespace keyboard
-
-#endif  // UI_KEYBOARD_KEYBOARD_UI_CONTROLLER_H_