FirstMeaningfulPaint UMA

chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc

Index: chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc
index 4cdc73f92eb24c8bb6258533f2fccfd523006ca1..4d370224e48a8738d99baa149b6692af7939cc24 100644
--- a/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc
+++ b/chrome/browser/page_load_metrics/observers/core_page_load_metrics_observer.cc
@@ -62,6 +62,13 @@ PageLoadType GetPageLoadType(ui::PageTransition transition) {
   return LOAD_TYPE_NONE;
 }
 
+enum FirstMeaningfulPaintStatus {
+  FMP_RECORDED,
+  FMP_DID_NOT_REACH_NETWORK_STABLE,
+  FMP_USER_INTERACTION_BEFORE_FMP,
+  FMP_ENUM_MAX
+};
+
 }  // namespace
 
 namespace internal {
@@ -99,6 +106,10 @@ const char kHistogramFirstContentfulPaint[] =
     "PageLoad.PaintTiming.NavigationToFirstContentfulPaint";
 const char kBackgroundHistogramFirstContentfulPaint[] =
     "PageLoad.PaintTiming.NavigationToFirstContentfulPaint.Background";
+const char kHistogramFirstMeaningfulPaint[] =
+    "PageLoad.PaintTiming.NavigationToFirstMeaningfulPaint";

[Bryan McQuade, 2016/08/03 21:44:58]

given that these are currently experimental, I'm inclined to tag them as such
for now in the histogram name. Maybe
"PageLoad.Experimental.PaintTiming.NavigationToFirstMeaningfulPaint"
?

Essentially use an "Experimental" in the name for any metric that we don't yet
have total confidence in?

[Kunihiko Sakamoto, 2016/08/04 01:47:36]

Yeah it's a nice idea, thanks.
Done.

+const char kBackgroundHistogramFirstMeaningfulPaint[] =
+    "PageLoad.PaintTiming.NavigationToFirstMeaningfulPaint.Background";

[Bryan McQuade, 2016/08/03 21:44:58]

same experimental here?

[Kunihiko Sakamoto, 2016/08/04 01:47:36]

Done.

 const char kHistogramParseStartToFirstContentfulPaint[] =
     "PageLoad.PaintTiming.ParseStartToFirstContentfulPaint";
 const char kBackgroundHistogramParseStartToFirstContentfulPaint[] =
@@ -107,6 +118,10 @@ const char kHistogramParseStart[] =
     "PageLoad.ParseTiming.NavigationToParseStart";
 const char kBackgroundHistogramParseStart[] =
     "PageLoad.ParseTiming.NavigationToParseStart.Background";
+const char kHistogramFirstMeaningfulPaintToNetworkStable[] =
+    "PageLoad.PaintTiming.FirstMeaningfulPaintToNetworkStable";
+const char kBackgroundHistogramFirstMeaningfulPaintToNetworkStable[] =
+    "PageLoad.PaintTiming.FirstMeaningfulPaintToNetworkStable.Background";
 const char kHistogramParseDuration[] = "PageLoad.ParseTiming.ParseDuration";
 const char kBackgroundHistogramParseDuration[] =
     "PageLoad.ParseTiming.ParseDuration.Background";
@@ -161,11 +176,15 @@ const char kHistogramForegroundToFirstPaint[] =
 const char kRapporMetricsNameCoarseTiming[] =
     "PageLoad.CoarseTiming.NavigationToFirstContentfulPaint";
 
+const char kHistogramFirstMeaningfulPaintStatus[] =
+    "PageLoad.PaintTiming.FirstMeaningfulPaintStatus";

[Bryan McQuade, 2016/08/03 21:44:58]

experimental

[Kunihiko Sakamoto, 2016/08/04 01:47:36]

Done.

+
 }  // namespace internal
 
 CorePageLoadMetricsObserver::CorePageLoadMetricsObserver()
     : transition_(ui::PAGE_TRANSITION_LINK),
-      initiated_by_user_gesture_(false) {}
+      initiated_by_user_gesture_(false),
+      had_first_paint_(false) {}
 
 CorePageLoadMetricsObserver::~CorePageLoadMetricsObserver() {}
 
@@ -173,6 +192,7 @@ void CorePageLoadMetricsObserver::OnCommit(
     content::NavigationHandle* navigation_handle) {
   transition_ = navigation_handle->GetPageTransition();
   initiated_by_user_gesture_ = navigation_handle->HasUserGesture();
+  navigation_start_ = navigation_handle->NavigationStart();
 }
 
 void CorePageLoadMetricsObserver::OnDomContentLoadedEventStart(
@@ -217,6 +237,8 @@ void CorePageLoadMetricsObserver::OnFirstLayout(
 void CorePageLoadMetricsObserver::OnFirstPaint(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
+  had_first_paint_ = true;
+
   if (WasStartedInForegroundOptionalEventInForeground(timing.first_paint,
                                                       info)) {
     PAGE_LOAD_HISTOGRAM(internal::kHistogramFirstPaint,
@@ -311,6 +333,37 @@ void CorePageLoadMetricsObserver::OnFirstContentfulPaint(
   }
 }
 
+void CorePageLoadMetricsObserver::OnFirstMeaningfulPaint(
+    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::PageLoadExtraInfo& info) {
+  base::TimeTicks fmp =
+      navigation_start_ + timing.first_meaningful_paint.value();
+  if (first_user_interaction_after_first_paint_.is_null() ||
+      fmp < first_user_interaction_after_first_paint_) {
+    base::TimeDelta time_since_fmp = base::TimeTicks::Now() - fmp;
+    if (WasStartedInForegroundOptionalEventInForeground(
+            timing.first_meaningful_paint, info)) {
+      PAGE_LOAD_HISTOGRAM(internal::kHistogramFirstMeaningfulPaint,
+          timing.first_meaningful_paint.value());
+      PAGE_LOAD_HISTOGRAM(
+          internal::kHistogramFirstMeaningfulPaintToNetworkStable,
+          time_since_fmp);
+    } else {
+      PAGE_LOAD_HISTOGRAM(
+          internal::kBackgroundHistogramFirstMeaningfulPaint,
+          timing.first_meaningful_paint.value());
+      PAGE_LOAD_HISTOGRAM(
+          internal::kBackgroundHistogramFirstMeaningfulPaintToNetworkStable,
+          time_since_fmp);
+    }
+    UMA_HISTOGRAM_ENUMERATION(internal::kHistogramFirstMeaningfulPaintStatus,
+        FMP_RECORDED, FMP_ENUM_MAX);
+  } else {
+    UMA_HISTOGRAM_ENUMERATION(internal::kHistogramFirstMeaningfulPaintStatus,
+        FMP_USER_INTERACTION_BEFORE_FMP, FMP_ENUM_MAX);
+  }
+}
+
 void CorePageLoadMetricsObserver::OnParseStart(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
@@ -396,6 +449,14 @@ void CorePageLoadMetricsObserver::OnFailedProvisionalLoad(
   }
 }
 
+void CorePageLoadMetricsObserver::OnUserInput(
+    const blink::WebInputEvent& event) {
+  if (had_first_paint_ && first_user_interaction_after_first_paint_.is_null() &&
+      event.type != blink::WebInputEvent::MouseMove) {
+    first_user_interaction_after_first_paint_ = base::TimeTicks::Now();
+  }
+}
+
 void CorePageLoadMetricsObserver::RecordTimingHistograms(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
@@ -431,6 +492,11 @@ void CorePageLoadMetricsObserver::RecordTimingHistograms(
       PAGE_LOAD_HISTOGRAM(internal::kHistogramFirstForeground,
                           info.first_foreground_time.value());
   }
+
+  if (!timing.first_meaningful_paint) {

[Bryan McQuade, 2016/08/03 21:44:58]

let's only record this if we actually got a first_paint as well. so:
if (timing.first_paint && !timing.first_meaningful_paint) {
...
}

[Kunihiko Sakamoto, 2016/08/04 01:47:36]

Done.

+    UMA_HISTOGRAM_ENUMERATION(internal::kHistogramFirstMeaningfulPaintStatus,
+                              FMP_DID_NOT_REACH_NETWORK_STABLE, FMP_ENUM_MAX);
+  }
 }
 
 void CorePageLoadMetricsObserver::RecordRappor(