ChromeLaunchController does proper action when extension unloaded

chrome/browser/ui/ash/launcher/chrome_launcher_controller.h

Index: chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
diff --git a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
index d5f4e82b46a414e92ad7f4071091a7eea2e1776d..bf4dd19557376bca6ca30351d12286e41d2fd28c 100644
--- a/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
+++ b/chrome/browser/ui/ash/launcher/chrome_launcher_controller.h
@@ -31,8 +31,7 @@
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_types.h"
 #include "chrome/browser/ui/extensions/extension_enable_flow_delegate.h"
 #include "chrome/common/extensions/extension_constants.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
+#include "extensions/browser/extension_registry_observer.h"
 #include "ui/aura/window_observer.h"
 
 class AppSyncUIState;
@@ -61,6 +60,7 @@ class WebContents;
 
 namespace extensions {
 class Extension;
+class ExtensionRegistry;
 }
 
 namespace ui {
@@ -93,9 +93,9 @@ class ChromeLauncherController : public ash::ShelfDelegate,
                                  public ash::ShelfModelObserver,
                                  public ash::ShellObserver,
                                  public ash::DisplayController::Observer,
-                                 public content::NotificationObserver,
                                  public extensions::AppIconLoader::Delegate,
                                  public PrefServiceSyncableObserver,
+                                 public extensions::ExtensionRegistryObserver,
                                  public AppSyncUIStateObserver,
                                  public ExtensionEnableFlowDelegate,
                                  public ash::ShelfLayoutManagerObserver {
@@ -308,10 +308,13 @@ class ChromeLauncherController : public ash::ShelfDelegate,
                                 const ash::ShelfItem& old_item) OVERRIDE;
   virtual void ShelfStatusChanged() OVERRIDE;
 
-  // content::NotificationObserver overrides:
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  virtual void OnExtensionLoaded(
+      content::BrowserContext* browser_context,
+      const extensions::Extension* extension) OVERRIDE;
+  virtual void OnExtensionUnloaded(
+      content::BrowserContext* browser_context,
+      const extensions::Extension* extension,
+      extensions::UnloadedExtensionInfo::Reason reason) OVERRIDE;
 
   // ash::ShellObserver overrides:
   virtual void OnShelfAlignmentChanged(aura::Window* root_window) OVERRIDE;
@@ -575,7 +578,8 @@ class ChromeLauncherController : public ash::ShelfDelegate,
   // Used to load the image for an app item.
   scoped_ptr<extensions::AppIconLoader> app_icon_loader_;
 
-  content::NotificationRegistrar notification_registrar_;
+  // Used to get extension loaded, unloaded notifications.
+  extensions::ExtensionRegistry* extension_registry_;
 
   PrefChangeRegistrar pref_change_registrar_;