Implement virtual keyboard hiding.

ui/keyboard/keyboard_ui_handler.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_HANDLER_H_
 #define UI_KEYBOARD_KEYBOARD_UI_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "content/public/browser/web_ui_message_handler.h"
@@ skipping 16 matching lines @@
 
   // Callback for the "getInputContext" message. The first element in
   // |args| should be an integer representing request ID.
   void HandleGetInputContextMessage(const base::ListValue* args);
 
   // Callback for the "sendKeyEvent" message. The first element in |args| is a
   // dictionary containing an event type, the character being pressed or
   // released, a virtual key code, and the state of the shift key.
   void HandleSendKeyEventMessage(const base::ListValue* args);
 
+  // Callback for the "hideKeyboard" message.
+  void HandleHideKeyboard(const base::ListValue* args);
+
   DISALLOW_COPY_AND_ASSIGN(KeyboardUIHandler);
 };
 
 }  // namespace keyboard
 
 #endif  // UI_KEYBOARD_KEYBOARD_UI_HANDLER_H_