Enable/disable extensions upon changes in blacklist.

extensions/common/extension.h

 // Copyright (c) 2013 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 EXTENSIONS_COMMON_EXTENSION_H_
 #define EXTENSIONS_COMMON_EXTENSION_H_
 
 #include <algorithm>
 #include <iosfwd>
 #include <map>
@@ skipping 72 matching lines @@
   enum DisableReason {
     DISABLE_NONE = 0,
     DISABLE_USER_ACTION = 1 << 0,
     DISABLE_PERMISSIONS_INCREASE = 1 << 1,
     DISABLE_RELOAD = 1 << 2,
     DISABLE_UNSUPPORTED_REQUIREMENT = 1 << 3,
     DISABLE_SIDELOAD_WIPEOUT = 1 << 4,
     DISABLE_UNKNOWN_FROM_SYNC = 1 << 5,
     DISABLE_PERMISSIONS_CONSENT = 1 << 6,  // Unused - abandoned experiment.
     DISABLE_KNOWN_DISABLED = 1 << 7,
-
-    // Disabled because we could not verify the install.
-    DISABLE_NOT_VERIFIED = 1 << 8,
+    DISABLE_NOT_VERIFIED = 1 << 8,  // Disabled because we could not verify
+                                    // the install.
+    DISABLE_GREYLIST = 1 << 9
   };
 
   enum InstallType {
     INSTALL_ERROR,
     DOWNGRADE,
     REINSTALL,
     UPGRADE,
     NEW_INSTALL
   };
 
@@ skipping 425 matching lines @@
 
   UpdatedExtensionPermissionsInfo(
       const Extension* extension,
       const PermissionSet* permissions,
       Reason reason);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_EXTENSION_H_