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

chrome/common/extensions/extension.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_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_H_
 #pragma once
 
 #include <algorithm>
 #include <map>
@@ skipping 275 matching lines @@
            location == Extension::EXTERNAL_POLICY_DOWNLOAD;
   }
 
   // Whether extensions with |location| are auto-updatable or not.
   static inline bool IsAutoUpdateableLocation(Location location) {
     // Only internal and external extensions can be autoupdated.
     return location == Extension::INTERNAL ||
            IsExternalLocation(location);
   }
 
-  // Whether extensions with |location| can be uninstalled or not. Policy
-  // controlled extensions are silently auto-installed and updated, and cannot
-  // be disabled by the user. The same applies for internal components.
-  static inline bool UserMayDisable(Location location) {
-    return location != Extension::EXTERNAL_POLICY_DOWNLOAD &&
-           location != Extension::COMPONENT;
+  // Policy-required extensions are silently auto-installed and updated, and
+  // cannot be disabled or modified by the user in any way. The same applies
+  // to internal components.
+  // This method is not generally called directly; instead, it is accessed
+  // through the ManagementPolicy held by the ExtensionSystem.
+  static inline bool IsRequired(Location location) {
+    return location == Extension::EXTERNAL_POLICY_DOWNLOAD ||
+           location == Extension::COMPONENT;
   }
 
   // Unpacked extensions start off with file access since they are a developer
   // feature.
   static inline bool ShouldAlwaysAllowFileAccess(Location location) {
     return location == Extension::LOAD;
   }
 
   // Fills the |info| dictionary with basic information about the extension.
   // |enabled| is injected for easier testing.
@@ skipping 800 matching lines @@
 
   UpdatedExtensionPermissionsInfo(
       const Extension* extension,
       const ExtensionPermissionSet* permissions,
       Reason reason);
 };
 
 } // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_H_