Remove unused variables.

chrome/browser/chromeos/language_preferences.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 CHROME_BROWSER_CHROMEOS_LANGUAGE_PREFERENCES_H_
 #define CHROME_BROWSER_CHROMEOS_LANGUAGE_PREFERENCES_H_
 #pragma once
 
 #include <stddef.h>  // For size_t
 
@@ skipping 48 matching lines @@
   int max_pref_value;
   const char* ibus_config_name;
   int message_id;
   PrefService::PrefSyncStatus sync_status;
 };
 
 // ---------------------------------------------------------------------------
 // For ibus-daemon
 // ---------------------------------------------------------------------------
 extern const char kGeneralSectionName[];
-extern const char kHotKeySectionName[];
 extern const char kPreloadEnginesConfigName[];
 
 // ---------------------------------------------------------------------------
 // For Traditional Chinese input method (ibus-mozc-chewing)
 // ---------------------------------------------------------------------------
 extern const char kChewingSectionName[];
 
 extern const LanguageBooleanPrefs kChewingBooleanPrefs[];
 // This is not ideal, but we should hard-code the number here as the value
 // is referenced in other header files as array sizes. We have a
@@ skipping 82 matching lines @@
 // the login screen.
 extern const char kPreferredKeyboardLayout[];
 
 // Registers non-user prefs for the default keyboard layout on the login screen.
 void RegisterPrefs(PrefService* local_state);
 
 }  // language_prefs
 }  // chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LANGUAGE_PREFERENCES_H_