Track which apps the user has re-ordered on the NTP.

chrome/browser/extensions/extension_prefs.h

Index: chrome/browser/extensions/extension_prefs.h
diff --git a/chrome/browser/extensions/extension_prefs.h b/chrome/browser/extensions/extension_prefs.h
index 12ed88ae61e203b692b80e13827fdbfa673f90fa..b48f6179d192ca1289da2c550a43224db1fb2a25 100644
--- a/chrome/browser/extensions/extension_prefs.h
+++ b/chrome/browser/extensions/extension_prefs.h
@@ -260,6 +260,14 @@ class ExtensionPrefs {
   // Sets the order the apps should be displayed in the app launcher.
   void SetAppLauncherOrder(const std::vector<std::string>& extension_ids);
 
+  // Returns true if the user repositioned the app on the app launcher via drag
+  // and drop.
+  bool WasAppDraggedByUser(const std::string& extension_id);
+
+  // Sets a flag indicating that the user repositioned the app on the app
+  // launcher by drag and dropping it.
+  void SetAppDraggedByUser(const std::string& extension_id);
+
   // The extension's update URL data.  If not empty, the ExtensionUpdater
   // will append a ap= parameter to the URL when checking if a new version
   // of the extension is available.