Revert of Use ExtensionRegistryObserver

chrome/browser/autocomplete/shortcuts_backend.h

Index: chrome/browser/autocomplete/shortcuts_backend.h
diff --git a/chrome/browser/autocomplete/shortcuts_backend.h b/chrome/browser/autocomplete/shortcuts_backend.h
index 5729cea26892466adfe783ed94eea01892064267..64f3bcc5f6434dd9cf7c8990fe3120b77bcec31b 100644
--- a/chrome/browser/autocomplete/shortcuts_backend.h
+++ b/chrome/browser/autocomplete/shortcuts_backend.h
@@ -14,7 +14,6 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
-#include "base/scoped_observer.h"
 #include "base/strings/string16.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
@@ -23,14 +22,9 @@
 #include "components/keyed_service/content/refcounted_browser_context_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
-#include "extensions/browser/extension_registry_observer.h"
 #include "url/gurl.h"
 
 class Profile;
-
-namespace extensions {
-class ExtensionRegistry;
-}
 
 namespace history {
 class ShortcutsDatabase;
@@ -39,8 +33,7 @@
 // This class manages the shortcut provider backend - access to database on the
 // db thread, etc.
 class ShortcutsBackend : public RefcountedBrowserContextKeyedService,
-                         public content::NotificationObserver,
-                         public extensions::ExtensionRegistryObserver {
+                         public content::NotificationObserver {
  public:
   typedef std::multimap<base::string16,
                         const history::ShortcutsDatabase::Shortcut> ShortcutMap;
@@ -111,12 +104,6 @@
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
-  // extensions::ExtensionRegistryObserver:
-  virtual void OnExtensionUnloaded(
-      content::BrowserContext* browser_context,
-      const extensions::Extension* extension,
-      extensions::UnloadedExtensionInfo::Reason reason) OVERRIDE;
-
   // Internal initialization of the back-end. Posted by Init() to the DB thread.
   // On completion posts InitCompleted() back to UI thread.
   void InitInternal();
@@ -158,10 +145,6 @@
 
   content::NotificationRegistrar notification_registrar_;
 
-  ScopedObserver<extensions::ExtensionRegistry,
-                 extensions::ExtensionRegistryObserver>
-      extension_registry_observer_;
-
   // For some unit-test only.
   bool no_db_access_;