Add metrics for calculating precision/recall of link navigation pre-connect triggers.

chrome/browser/net/predictor.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A Predictor object is instantiated once in the browser process, and manages
 // both preresolution of hostnames, as well as TCP/IP preconnection to expected
 // subresources.
 // Most hostname lists are provided by the renderer processes, and include URLs
 // that *might* be used in the near future by the browsing user.  One goal of
 // this class is to cause the underlying DNS structure to lookup a hostname
@@ skipping 220 matching lines @@
   // May be called from either the IO or UI thread and will PostTask
   // to the IO thread if necessary.
   void PreconnectUrl(const GURL& url, const GURL& first_party_for_cookies,
                      UrlInfo::ResolutionMotivation motivation, int count);
 
   void PreconnectUrlOnIOThread(const GURL& url,
                                const GURL& first_party_for_cookies,
                                UrlInfo::ResolutionMotivation motivation,
                                int count);
 
-  void RecordPreconnectNavigationStats(const GURL& url);
+  void RecordPreconnectTrigger(const GURL& url);
+
+  void RecordPreconnectNavigationStat(const std::vector<GURL>& url_chain,
+                                      bool is_subresource);
+
+  void RecordLinkNavigation(const GURL& url);
 
   // ------------- End IO thread methods.
 
   // The following methods may be called on either the IO or UI threads.
 
   // Instigate pre-connection to any URLs, or pre-resolution of related host,
   // that we predict will be needed after this navigation (typically
   // more-embedded resources on a page).  This method will actually post a task
   // to do the actual work, so as not to jump ahead of the frame navigation that
   // instigated this activity.
@@ skipping 250 matching lines @@
   // The time when the last preresolve was done for last_omnibox_host_.
   base::TimeTicks last_omnibox_preresolve_;
 
   // The number of consecutive requests to AnticipateOmniboxUrl() that suggested
   // preconnecting (because it was to a search service).
   int consecutive_omnibox_preconnect_count_;
 
   // The time when the last preconnection was requested to a search service.
   base::TimeTicks last_omnibox_preconnect_;
 
-  TimedCache recent_preconnects_;
+  class PreconnectUsage;
+  scoped_ptr<PreconnectUsage> preconnect_usage_;
 
   // For each URL that we might navigate to (that we've "learned about")
   // we have a Referrer list. Each Referrer list has all hostnames we might
   // need to pre-resolve or pre-connect to when there is a navigation to the
   // orginial hostname.
   Referrers referrers_;
 
   // List of URLs in referrers_ currently being trimmed (scaled down to
   // eventually be aged out of use).
   std::vector<GURL> urls_being_trimmed_;
@@ skipping 16 matching lines @@
       PrefService* user_prefs,
       PrefService* local_state,
       IOThread* io_thread,
       net::URLRequestContextGetter* getter) OVERRIDE;
   virtual void ShutdownOnUIThread(PrefService* user_prefs) OVERRIDE;
 };
 
 }  // namespace chrome_browser_net
 
 #endif  // CHROME_BROWSER_NET_PREDICTOR_H_