Separate the NTP app ordering from the app list app ordering

chrome/browser/extensions/install_tracker.h

Index: chrome/browser/extensions/install_tracker.h
diff --git a/chrome/browser/extensions/install_tracker.h b/chrome/browser/extensions/install_tracker.h
index c8b2c477fea278be2fce5a95f09582e16a57564e..80ed793ac46ad8cc249a69fb40a813a982666a8a 100644
--- a/chrome/browser/extensions/install_tracker.h
+++ b/chrome/browser/extensions/install_tracker.h
@@ -8,10 +8,12 @@
 #include "base/observer_list.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "chrome/browser/extensions/install_observer.h"
+#include "chrome/browser/ui/app_list/app_list_extension_sorting_observer.h"
 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
+class AppListExtensionSorting;
 class Profile;
 
 namespace gfx {
@@ -23,7 +25,8 @@ namespace extensions {
 class ExtensionPrefs;
 
 class InstallTracker : public BrowserContextKeyedService,
-                       public content::NotificationObserver {
+                       public content::NotificationObserver,
+                       public AppListExtensionSortingObserver {
  public:
   InstallTracker(Profile* profile,
                  extensions::ExtensionPrefs* prefs);
@@ -42,17 +45,21 @@ class InstallTracker : public BrowserContextKeyedService,
                           int percent_downloaded);
   void OnInstallFailure(const std::string& extension_id);
 
-  // Overriddes for BrowserContextKeyedService:
+  // Overrides for BrowserContextKeyedService:
   virtual void Shutdown() OVERRIDE;
 
-  // content::NotificationObserver
+  // Overrides for content::NotificationObserver:
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
+  // Overrides for AppListExtensionSortingObserver:
+  virtual void OnAppListReordered() OVERRIDE;
+
  private:
-  void OnAppsReordered();
+  void ExtensionPrefsChanged();
 
+  AppListExtensionSorting* app_list_extension_sorting_;
   ObserverList<InstallObserver> observers_;
   content::NotificationRegistrar registrar_;
   PrefChangeRegistrar pref_change_registrar_;