Perform install tasks for newly installed or upgraded component apps/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_
 
 #include <algorithm>
 #include <iosfwd>
 #include <map>
@@ skipping 81 matching lines @@
 
     NUM_LOCATIONS
   };
 
   enum State {
     DISABLED = 0,
     ENABLED,
     // An external extension that the user uninstalled. We should not reinstall
     // such extensions on startup.
     EXTERNAL_EXTENSION_UNINSTALLED,
+    // Special state for component extensions, since they are always loaded by
+    // the component loader, and should never be auto-installed on startup.
+    ENABLED_COMPONENT,
     NUM_STATES
   };
 
   // Used to record the reason an extension was disabled.
   enum DeprecatedDisableReason {
     DEPRECATED_DISABLE_UNKNOWN,
     DEPRECATED_DISABLE_USER_ACTION,
     DEPRECATED_DISABLE_PERMISSIONS_INCREASE,
     DEPRECATED_DISABLE_RELOAD,
     DEPRECATED_DISABLE_LAST,  // Not used.
@@ skipping 1171 matching lines @@
 
   UpdatedExtensionPermissionsInfo(
       const Extension* extension,
       const PermissionSet* permissions,
       Reason reason);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_H_