Remove unimplemented methods from PrerenderTracker.

In http://codereview.chromium.org/10006041 we removed the definition
of these two methods, but not their declarations.

BUG=None


Review URL: https://chromiumcodereview.appspot.com/10384059

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@137830 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/prerender/prerender_tracker.h

@@ -56,9 +56,6 @@ class PrerenderTracker {
   bool TryCancelOnIOThread(int child_id, int route_id,
                            FinalStatus final_status);
 
-  void AddPrerenderURLOnUIThread(const GURL& url);
-  void RemovePrerenderURLsOnUIThread(const std::vector<GURL>& urls);
-
   // Gets the FinalStatus of the specified prerendered RenderView.  Returns
   // |true| and sets |final_status| to the status of the RenderView if it
   // is found, returns false otherwise.