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

chrome/browser/net/predictor.h

Index: chrome/browser/net/predictor.h
diff --git a/chrome/browser/net/predictor.h b/chrome/browser/net/predictor.h
index b56a62bdf913840cb937999a953b3be0569b9036..0b083801337075e8eb5c0c299b041ccb0c3e7f13 100644
--- a/chrome/browser/net/predictor.h
+++ b/chrome/browser/net/predictor.h
@@ -233,12 +233,21 @@ class Predictor {
   void PreconnectUrl(const GURL& url, const GURL& first_party_for_cookies,
                      UrlInfo::ResolutionMotivation motivation, int count);
 
+  // May be called from either the IO or UI thread and will PostTask

[cbentzel, 2013/06/24 10:48:39]

Is this comment correct? The name of it seems to indicate that it must be called
on the IO thread.

[kouhei (in TOK), 2013/06/25 03:33:50]

Sorry I put this by mistake. Thank you for pointing it out.

+  // to the IO thread if necessary.
   void PreconnectUrlOnIOThread(const GURL& url,
                                const GURL& first_party_for_cookies,
                                UrlInfo::ResolutionMotivation motivation,
                                int count);
 
-  void RecordPreconnectNavigationStats(const GURL& url);
+  // May be called from either the IO or UI thread and will PostTask
+  // to the IO thread if necessary.
+  void RecordPreconnectTrigger(const GURL& url);
+
+  // May be called from either the IO or UI thread and will PostTask
+  // to the IO thread if necessary.
+  void RecordPreconnectNavigationStat(const GURL& url,
+                                      const GURL& original_url);
 
   // ------------- End IO thread methods.
 
@@ -453,6 +462,11 @@ class Predictor {
   // continue with them shortly (i.e., it yeilds and continues).
   void IncrementalTrimReferrers(bool trim_all_now);
 
+  void RecordPreconnectTriggerOnIOThread(const GURL& url);
+
+  void RecordPreconnectNavigationStatOnIOThread(const GURL& url,
+                                                const GURL& original_url);
+
   // ------------- End IO thread methods.
 
   scoped_ptr<InitialObserver> initial_observer_;
@@ -509,7 +523,8 @@ class Predictor {
   // 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