ntp: remove ShownSectionHandler and all references to it

chrome/browser/ui/webui/ntp/new_tab_ui.h

Index: chrome/browser/ui/webui/ntp/new_tab_ui.h
diff --git a/chrome/browser/ui/webui/ntp/new_tab_ui.h b/chrome/browser/ui/webui/ntp/new_tab_ui.h
index 58f4083c61b4013bdc8cf4dda5537fd2018c899d..2f5edada4a5f162d512a2a6e89cf5e44fd29f167 100644
--- a/chrome/browser/ui/webui/ntp/new_tab_ui.h
+++ b/chrome/browser/ui/webui/ntp/new_tab_ui.h
@@ -35,8 +35,6 @@ class NewTabUI : public ChromeWebUI,
   virtual void RenderViewReused(RenderViewHost* render_view_host) OVERRIDE;
 
   static void RegisterUserPrefs(PrefService* prefs);
-  static void MigrateUserPrefs(PrefService* prefs, int old_pref_version,
-                               int new_pref_version);
 
   // Adds "url", "title", and "direction" keys on incoming dictionary, setting
   // title as the url as a fallback on empty title.
@@ -89,10 +87,6 @@ class NewTabUI : public ChromeWebUI,
   void StartTimingPaint(RenderViewHost* render_view_host);
   void PaintTimeout();
 
-  // Updates the user prefs version and calls |MigrateUserPrefs| if needed.
-  // Returns true if the version was updated.
-  static bool UpdateUserPrefsVersion(PrefService* prefs);
-
   // Overridden from ChromeWebUI. Determines if the bookmarks bar can be shown
   // detached from the location bar.
   virtual bool CanShowBookmarkBar() const OVERRIDE;