Refactor the various ways to control what users can do to extensions.

chrome/common/extensions/extension_constants.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_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #pragma once
 
 #include <string>
 
@@ skipping 51 matching lines @@
   // background.scripts.
   extern const char kGeneratedBackgroundPageFilename[];
 }
 
 // Keys in the dictionary returned by Extension::GetBasicInfo().
 namespace extension_info_keys {
   extern const char kDescriptionKey[];
   extern const char kEnabledKey[];
   extern const char kHomepageUrlKey[];
   extern const char kIdKey[];
-  extern const char kMayDisableKey[];
   extern const char kNameKey[];
   extern const char kOfflineEnabledKey[];
   extern const char kOptionsUrlKey[];
   extern const char kVersionKey[];
 }
 
 namespace extension_misc {
   // Matches chrome.windows.WINDOW_ID_NONE.
   const int kUnknownWindowId = -1;
 
@@ skipping 166 matching lines @@
   extern const char kAppStateRunning[];
   extern const char kAppStateCannotRun[];
   extern const char kAppStateReadyToRun[];
 
   // Error indicating that the app notifications API is not accessible by split
   // mode extensions in incognito windows.
   extern const char kAppNotificationsIncognitoError[];
 }  // extension_misc
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_