[Prerender] first contentful paint histograms.

chrome/browser/prerender/prerender_histograms.cc

Index: chrome/browser/prerender/prerender_histograms.cc
diff --git a/chrome/browser/prerender/prerender_histograms.cc b/chrome/browser/prerender/prerender_histograms.cc
index 4e97663049a8d3e75b14b55e98a28ec60af7f2cc..2955b0add71727f813a5f418f9d17ccd7a83a899 100644
--- a/chrome/browser/prerender/prerender_histograms.cc
+++ b/chrome/browser/prerender/prerender_histograms.cc
@@ -310,6 +310,27 @@ void PrerenderHistograms::RecordPerceivedPageLoadTime(
   }
 }
 
+void PrerenderHistograms::RecordPerceivedFirstContentfulPaintTime(
+    Origin origin,
+    base::TimeDelta perceived_first_contentful_paint,
+    bool was_hidden) {
+  RecordHistogramTime(GetPerceivedFirstContentfulPaintHistogramName(
+                          origin, IsOriginWash(), was_hidden),
+                      base::TimeDelta::FromMilliseconds(10),
+                      base::TimeDelta::FromMinutes(2),
+                      perceived_first_contentful_paint, 50);
+}
+
+void PrerenderHistograms::RecordPerceivedFirstContentfulPaintStatus(
+    Origin origin,
+    bool successful,
+    bool was_hidden) {
+  RecordHistogramEnum(
+      GetHistogramName(origin, IsOriginWash(), "PerceivedTTFCPRecorded") +

[droger, 2016/11/24 13:03:43]

If we want to compare NoStatePrefetch vs Prerender vs Control using a UMA
experiment, we need to report all the TTFCP in a single histogram, and then use
Finch to compare.

So in practice I think we should merge this histogram and the
"NoStatePrefetchTTFCP" histograms.

Another option would be to keep these histograms if they have some value, and
add another one that would be the merge of all of them. This could then be done
in another CL.

+          FirstContentfulPaintHiddenName(was_hidden),
+      successful ? 1 : 0, 2);
+}
+
 void PrerenderHistograms::RecordPageLoadTimeNotSwappedIn(
     Origin origin,
     base::TimeDelta page_load_time,
@@ -452,7 +473,7 @@ void PrerenderHistograms::RecordPrefetchRedirectCount(
   RecordHistogramEnum(histogram_name, redirect_count, kMaxRedirectCount);
 }
 
-void PrerenderHistograms::RecordFirstContentfulPaint(
+void PrerenderHistograms::RecordNoStateFirstContentfulPaint(
     Origin origin,
     bool is_no_store,
     base::TimeDelta time,
@@ -467,7 +488,7 @@ void PrerenderHistograms::RecordFirstContentfulPaint(
                         base::TimeDelta::FromMinutes(30), prefetch_age, 50);
   }
 
-  RecordHistogramTime(GetFirstContentfulPaintHistogramName(
+  RecordHistogramTime(GetNoStateFirstContentfulPaintHistogramName(
                           origin, IsOriginWash(), is_no_store, prefetch_age),
                       base::TimeDelta::FromMilliseconds(10),
                       base::TimeDelta::FromMinutes(2), time, 50);
@@ -480,7 +501,7 @@ bool PrerenderHistograms::IsOriginWash() const {
 }
 
 // static
-std::string PrerenderHistograms::GetFirstContentfulPaintHistogramName(
+std::string PrerenderHistograms::GetNoStateFirstContentfulPaintHistogramName(
     Origin origin,
     bool is_wash,
     bool is_no_store,
@@ -499,4 +520,18 @@ std::string PrerenderHistograms::GetFirstContentfulPaintHistogramName(
   return GetHistogramName(origin, is_wash, histogram_base_name);
 }
 
+// static
+std::string PrerenderHistograms::GetPerceivedFirstContentfulPaintHistogramName(
+    Origin origin,
+    bool is_wash,
+    bool was_hidden) {
+  return GetHistogramName(origin, is_wash, "PerceivedTTFCP") +
+         FirstContentfulPaintHiddenName(was_hidden);
+}
+
+std::string PrerenderHistograms::FirstContentfulPaintHiddenName(
+    bool was_hidden) {
+  return was_hidden ? ".Hidden" : ".Visible";
+}
+
 }  // namespace prerender