Record first paint in UKM.

chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer.cc

 // Copyright 2017 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.
 
 #include "chrome/browser/page_load_metrics/observers/ukm_page_load_metrics_observer.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/net/nqe/ui_network_quality_estimator_service.h"
 #include "chrome/browser/net/nqe/ui_network_quality_estimator_service_factory.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/ukm/public/ukm_entry_builder.h"
 #include "components/ukm/public/ukm_recorder.h"
 #include "content/public/browser/web_contents.h"
 
 namespace internal {
 
 const char kUkmPageLoadEventName[] = "PageLoad";
 const char kUkmParseStartName[] = "ParseTiming.NavigationToParseStart";
 const char kUkmDomContentLoadedName[] =
     "DocumentTiming.NavigationToDOMContentLoadedEventFired";
 const char kUkmLoadEventName[] = "DocumentTiming.NavigationToLoadEventFired";
+const char kUkmFirstPaintName[] = "PaintTiming.NavigationToFirstPaint";
 const char kUkmFirstContentfulPaintName[] =
     "PaintTiming.NavigationToFirstContentfulPaint";
 const char kUkmFirstMeaningfulPaintName[] =
     "Experimental.PaintTiming.NavigationToFirstMeaningfulPaint";
 const char kUkmForegroundDurationName[] = "PageTiming.ForegroundDuration";
 const char kUkmFailedProvisionaLoadName[] =
     "PageTiming.NavigationToFailedProvisionalLoad";
 const char kUkmEffectiveConnectionType[] =
     "Net.EffectiveConnectionType.OnNavigationStart";
 const char kUkmHttpRttEstimate[] = "Net.HttpRttEstimate.OnNavigationStart";
@@ skipping 126 matching lines @@
     builder->AddMetric(
         internal::kUkmDomContentLoadedName,
         timing.document_timing->dom_content_loaded_event_start.value()
             .InMilliseconds());
   }
   if (timing.document_timing->load_event_start) {
     builder->AddMetric(
         internal::kUkmLoadEventName,
         timing.document_timing->load_event_start.value().InMilliseconds());
   }
+  if (timing.paint_timing->first_paint) {
+    builder->AddMetric(
+        internal::kUkmFirstPaintName,
+        timing.paint_timing->first_paint.value().InMilliseconds());
+  }
   if (timing.paint_timing->first_contentful_paint) {
     builder->AddMetric(
         internal::kUkmFirstContentfulPaintName,
         timing.paint_timing->first_contentful_paint.value().InMilliseconds());
   }
   if (timing.paint_timing->first_meaningful_paint) {
     builder->AddMetric(
         internal::kUkmFirstMeaningfulPaintName,
         timing.paint_timing->first_meaningful_paint.value().InMilliseconds());
   }
@@ skipping 26 matching lines @@
   }
   if (transport_rtt_estimate_) {
     builder->AddMetric(
         internal::kUkmTransportRttEstimate,
         static_cast<int64_t>(transport_rtt_estimate_.value().InMilliseconds()));
   }
   // page_transition_ fits in a uint32_t, so we can safely cast to int64_t.
   builder->AddMetric(internal::kUkmPageTransition,
                      static_cast<int64_t>(page_transition_));
 }