[Prerender] first contentful paint histograms.

chrome/browser/prerender/prerender_histograms.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.
 
 #ifndef CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 30 matching lines @@
   PrerenderHistograms();
 
   // 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(Origin origin,
                                    base::TimeDelta perceived_page_load_time,
                                    NavigationType navigation_type,
                                    const GURL& url);
 
+  // Record that a first contentful paint occured, and whether we were able to
+  // successfuly record the perceived FCP.
+  void RecordPerceivedFirstContentfulPaintStatus(Origin origin,
+                                                 bool successful,
+                                                 bool was_hidden);
+
   // 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(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(Origin origin,
                                       base::TimeDelta page_load_time,
                                       const GURL& url) const;
@@ skipping 49 matching lines @@
                                       bool is_main_resource,
                                       bool is_redirect,
                                       bool is_no_store) const;
 
   // Called when a NoStatePrefetch resource has been loaded. This is called only
   // once per resource, when all redirects have been resolved.
   void RecordPrefetchRedirectCount(Origin origin,
                                    bool is_main_resource,
                                    int redirect_count) const;
 
-  // Records the time to first contentful paint.
-  // Must not be called for prefetch loads (which are never rendered anyway).
-  // |is_no_store| must be true if the main resource has a "no-store" cache
-  // control HTTP header.
-  // |prefetch_age| must be zero if the page was not prefetched.
-  void RecordFirstContentfulPaint(Origin origin,
-                                  bool is_no_store,
-                                  base::TimeDelta time,
-                                  base::TimeDelta prefetch_age);
-
-  // Returns the name of the histogram used to record the time to first
-  // contentful paint.
-  // Exposed for testing.
-  static std::string GetFirstContentfulPaintHistogramName(
-      Origin origin,
-      bool is_wash,
-      bool is_no_store,
-      base::TimeDelta prefetch_age);
+  // Records the time to first contentful paint with respect to a possible
+  // prefetch of the page. The time to first contentful paint with respect to
+  // the navigation start is recorded (even if the page was prererendered in
+  // advance of navigation start). One of several histograms is used, depending
+  // on whether this URL could have been prefetched before the navigation
+  // leading to the paint.
+  void RecordPrefetchFirstContentfulPaintTime(Origin origin,
+                                              bool is_no_store,
+                                              bool was_hidden,
+                                              base::TimeDelta time,
+                                              base::TimeDelta prefetch_age);
 
  private:
   base::TimeTicks GetCurrentTimeTicks() const;
 
   // Returns the time elapsed since the last prerender happened.
   base::TimeDelta GetTimeSinceLastPrerender() const;
 
   // Returns whether the PrerenderManager is currently within the prerender
   // window - effectively, up to 30 seconds after a prerender tag has been
   // observed.
@@ skipping 21 matching lines @@
   bool seen_pageload_started_after_prerender_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderHistograms);
 };
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_