Fix prerender histograms for multiple prerender case.

chrome/browser/prerender/prerender_histograms.h

Index: chrome/browser/prerender/prerender_histograms.h
diff --git a/chrome/browser/prerender/prerender_histograms.h b/chrome/browser/prerender/prerender_histograms.h
index e77802fe4f6ca02ded7c7a017cccfee2873f9c0a..c79cee1bbdad6f5016f9c65d357930d558c0ffd4 100644
--- a/chrome/browser/prerender/prerender_histograms.h
+++ b/chrome/browser/prerender/prerender_histograms.h
@@ -26,12 +26,13 @@ class PrerenderHistograms {
  public:
   // Owned by a PrerenderManager object for the lifetime of the
   // PrerenderManager.
-  PrerenderHistograms();
+  explicit PrerenderHistograms(const base::TimeDelta prerender_ttl);
 
   // Records the perceived page load time for a page - effectively the time from
   // when the user navigates to a page to when it finishes loading.  The actual
   // load may have started prior to navigation due to prerender hints.
-  void RecordPerceivedPageLoadTime(base::TimeDelta perceived_page_load_time,
+  void RecordPerceivedPageLoadTime(Origin origin,
+                                   base::TimeDelta perceived_page_load_time,
                                    bool was_prerender,
                                    bool was_complete_prerender,
                                    const GURL& url);
@@ -39,33 +40,38 @@ class PrerenderHistograms {
   // Records, in a histogram, the percentage of the page load time that had
   // elapsed by the time it is swapped in.  Values outside of [0, 1.0] are
   // invalid and ignored.
-  void RecordPercentLoadDoneAtSwapin(double fraction) const;
+  void RecordPercentLoadDoneAtSwapin(Origin origin, double fraction) const;
 
   // Records the actual pageload time of a prerender that has not been swapped
   // in yet, but finished loading.
-  void RecordPageLoadTimeNotSwappedIn(base::TimeDelta page_load_time,
+  void RecordPageLoadTimeNotSwappedIn(Origin origin,
+                                      base::TimeDelta page_load_time,
                                       const GURL& url) const;
 
   // For simulated local browsing prerendering, records the PLT without
   // any local browsing prerendering.
-  void RecordSimulatedLocalBrowsingBaselinePLT(base::TimeDelta page_load_time,
+  void RecordSimulatedLocalBrowsingBaselinePLT(Origin origin,
+                                               base::TimeDelta page_load_time,
                                                const GURL& url) const;
 
   // For simulated local browsing prerendering, records the PLT with
   // local browsing prerendering.
-  void RecordSimulatedLocalBrowsingPLT(base::TimeDelta page_load_time,
+  void RecordSimulatedLocalBrowsingPLT(Origin origin,
+                                       base::TimeDelta page_load_time,
                                        const GURL& url) const;
 
   // Records the time from when a page starts prerendering to when the user
   // navigates to it. This must be called on the UI thread.
-  void RecordTimeUntilUsed(base::TimeDelta time_until_used,
+  void RecordTimeUntilUsed(Origin origin,
+                           base::TimeDelta time_until_used,
                            base::TimeDelta time_to_live) const;
 
   // Record a PerSessionCount data point.
-  void RecordPerSessionCount(int count) const;
+  void RecordPerSessionCount(Origin origin, int count) const;
 
   // Record time between two prerender requests.
-  void RecordTimeBetweenPrerenderRequests(base::TimeDelta time) const;
+  void RecordTimeBetweenPrerenderRequests(Origin origin,
+                                          base::TimeDelta time) const;
 
   // Record a final status of a prerendered page in a histogram.
   void RecordFinalStatus(Origin origin,
@@ -87,11 +93,12 @@ class PrerenderHistograms {
   void RecordUsedPrerender(Origin origin) const;
 
   // Record the time since a page was recently visited.
-  void RecordTimeSinceLastRecentVisit(base::TimeDelta time) const;
+  void RecordTimeSinceLastRecentVisit(Origin origin,
+                                      base::TimeDelta time) const;
 
   // Record a percentage of pixels of the final page already in place at
   // swap-in.
-  void RecordFractionPixelsFinalAtSwapin(double fraction) const;
+  void RecordFractionPixelsFinalAtSwapin(Origin origin, double fraction) const;
 
   // Record the occurrence of an event from the local predictor.
   void RecordLocalPredictorEvent(PrerenderLocalPredictor::Event event) const;
@@ -99,7 +106,8 @@ class PrerenderHistograms {
   // For the local predictor, records the time from when a page starts
   // prerendering to when the user navigates to it. This must be called on the
   // UI thread.
-  void RecordLocalPredictorTimeUntilUsed(base::TimeDelta time_until_used,
+  void RecordLocalPredictorTimeUntilUsed(Origin origin,
+                                         base::TimeDelta time_until_used,
                                          base::TimeDelta max_age) const;
 
  private:
@@ -115,8 +123,7 @@ class PrerenderHistograms {
 
   // Returns the current experiment.
   uint8 GetCurrentExperimentId() const;
-  // Returns the current origin.
-  Origin GetCurrentOrigin() const;
+
   // Returns whether or not there is currently an origin/experiment wash.
   bool IsOriginExperimentWash() const;
 
@@ -132,6 +139,10 @@ class PrerenderHistograms {
   // experiments / origins impossible.
   bool origin_experiment_wash_;
 
+  // The prerender time to live determines the window size for determining
+  // washes.
+  const base::TimeDelta prerender_ttl_;
+
   // The time when we last saw a prerender request coming from a renderer.
   // This is used to record perceived PLT's for a certain amount of time
   // from the point that we last saw a <link rel=prerender> tag.