[NoStatePrefetch] Cancel repeated prefetches with FINAL_STATUS_DUPLICATE

chrome/browser/prerender/prerender_manager.h

Index: chrome/browser/prerender/prerender_manager.h
diff --git a/chrome/browser/prerender/prerender_manager.h b/chrome/browser/prerender/prerender_manager.h
index 04780f73cdca11f02f7f218956b9ee6c3a1106ea..d29644c31f55c3da486f8e60ae87183bbc837672 100644
--- a/chrome/browser/prerender/prerender_manager.h
+++ b/chrome/browser/prerender/prerender_manager.h
@@ -540,10 +540,15 @@ class PrerenderManager : public content::NotificationObserver,
   void DeleteOldWebContents();
 
   // Get information associated with a possible prefetch of |url|.
+  // |origin| may be null, in which case the origin is not returned.
   void GetPrefetchInformation(const GURL& url,
                               base::TimeDelta* prefetch_age,
                               Origin* origin);
 
+  // Called when a prefetch has been used. Prefetches avoid cache revalidation
+  // only once.
+  void OnPrefetchUsed(const GURL& url);
+
   // Cleans up old NavigationRecord's.
   void CleanUpOldNavigations(std::vector<NavigationRecord>* navigations,
                              base::TimeDelta max_age);