Add onFontNameChanged event to Font Settings API

chrome/browser/extensions/extension_preference_api_constants.cc

 // 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.
 
 #include "chrome/browser/extensions/extension_preference_api_constants.h"
 
 namespace extension_preference_api_constants {
 
 const char kIncognitoKey[] = "incognito";
 
 const char kScopeKey[] = "scope";
 
-const char kNotControllable[] = "not_controllable";
-const char kControlledByOtherExtensions[] = "controlled_by_other_extensions";
-const char kControllableByThisExtension[] = "controllable_by_this_extension";
-const char kControlledByThisExtension[] = "controlled_by_this_extension";
-
 const char kIncognitoSpecific[] = "incognitoSpecific";
 const char kLevelOfControl[] = "levelOfControl";
 const char kValue[] = "value";
 
 const char kIncognitoErrorMessage[] =
     "You do not have permission to access incognito preferences.";
 
 const char kIncognitoSessionOnlyErrorMessage[] =
     "You cannot set a preference with scope 'incognito_session_only' when no "
     "incognito window is open.";
 
 const char kPermissionErrorMessage[] =
     "You do not have permission to access the preference '*'. "
     "Be sure to declare in your manifest what permissions you need.";
 
 }  // extension_preference_api_constants
-