Add pref entry for virtual keyboard

chrome/browser/chromeos/preferences.h

 // Copyright (c) 2011 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 CHROME_BROWSER_CHROMEOS_PREFERENCES_H_
 #define CHROME_BROWSER_CHROMEOS_PREFERENCES_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 11 matching lines @@
 // the preferences. These include touchpad settings, etc.
 // When the preferences change, we change the settings to reflect the new value.
 class Preferences : public NotificationObserver {
  public:
   Preferences();
   virtual ~Preferences();
 
   // This method will register the prefs associated with Chrome OS settings.
   static void RegisterUserPrefs(PrefService* prefs);
 
+  // This method is called when kLanguagePreferredVirtualKeyboard is updated to
+  // change the virtual keyboard settings to reflect the new value.
+  static void UpdateVirturalKeyboardPreference(PrefService* prefs);
+
   // This method will initialize Chrome OS settings to values in user prefs.
   void Init(PrefService* prefs);
 
   // Overridden from NotificationObserver:
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
  private:
   // This will set the OS settings when the preference changes.
@@ skipping 82 matching lines @@
   BooleanPrefMember enable_screen_lock_;
 
   BooleanPrefMember use_shared_proxies_;
 
   DISALLOW_COPY_AND_ASSIGN(Preferences);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PREFERENCES_H_