Fix the documentation of ExtensionRegistryObserver::OnExtensionUnloaded.

extensions/browser/extension_registry_observer.h

 // Copyright 2014 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_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
 #define EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_
 
 #include "extensions/browser/uninstall_reason.h"
 #include "extensions/common/extension.h"
 
@@ skipping 13 matching lines @@
  public:
   virtual ~ExtensionRegistryObserver() {}
 
   // Called after an extension is loaded. The extension will exclusively exist
   // in the enabled_extensions set of ExtensionRegistry.
   virtual void OnExtensionLoaded(
       content::BrowserContext* browser_context,
       const Extension* extension) {}
 
   // Called after an extension is unloaded. The extension no longer exists in
-  // any of the ExtensionRegistry sets (enabled, disabled, etc.).
+  // the set |ExtensionRegistry::enabled_extensions()|, but it can still be a
+  // member of one of the other sets, like disabled, blacklisted or terminated.
   virtual void OnExtensionUnloaded(content::BrowserContext* browser_context,
                                    const Extension* extension,
                                    UnloadedExtensionInfo::Reason reason) {}
 
   // Called when |extension| is about to be installed. |is_update| is true if
   // the installation is the result of it updating, in which case |old_name| is
   // the name of the extension's previous version.
   // If true, |from_ephemeral| indicates that the extension was previously
   // installed ephemerally and has been promoted to a regular installed
   // extension. |is_update| will be true, although the version has not
@@ skipping 28 matching lines @@
                                       const Extension* extension,
                                       UninstallReason reason) {}
 
   // Notifies observers that the observed object is going away.
   virtual void OnShutdown(ExtensionRegistry* registry) {}
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTENSION_REGISTRY_OBSERVER_H_