Added Instant preference syncing and tests.

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index e12bd6f411c81b7b336e8f4c602859ae3a3289c3..b327f1b0c43e3b9952e85765c184ba393af49212 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -206,6 +206,15 @@ class ExtensionService
   virtual void SetIsIncognitoEnabled(const std::string& extension_id,
                                      bool enabled);
 
+  // The position of App in the NTP
+  virtual int32 GetAppLaunchIndex(const std::string& extension_id) const;
+  virtual void SetAppLaunchIndex(const std::string& extension_id,
+                                 int32 app_launch_index);
+  virtual int32 GetPageIndex(const std::string& extension_id) const;
+  virtual void SetPageIndex(const std::string& extension_id,
+                            int32 page_index);
+  void SetAppLauncherOrder(const std::vector<std::string>& extension_ids);
+
   // Returns true if the given extension can see events and data from another
   // sub-profile (incognito to original profile, or vice versa).
   bool CanCrossIncognito(const Extension* extension);