Add a virtual keyboard webui at chrome://keyboard/

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_