Add metric with time between background tab being foregrounded and the first paint

chrome/browser/page_load_metrics/observers/stale_while_revalidate_metrics_observer.cc

 // Copyright 2015 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/stale_while_revalidate_metrics_observer.h"
 
 #include "components/page_load_metrics/browser/page_load_metrics_util.h"
 #include "components/page_load_metrics/common/page_load_timing.h"
 #include "content/public/browser/navigation_handle.h"
 #include "net/base/stale_while_revalidate_experiment_domains.h"
 
 namespace chrome {
 
 StaleWhileRevalidateMetricsObserver::StaleWhileRevalidateMetricsObserver()
     : is_interesting_domain_(false) {}
 
 void StaleWhileRevalidateMetricsObserver::OnCommit(
     content::NavigationHandle* navigation_handle) {
   is_interesting_domain_ = net::IsHostInStaleWhileRevalidateExperimentDomain(
       navigation_handle->GetURL().host());
 }
 
 void StaleWhileRevalidateMetricsObserver::OnComplete(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& extra_info) {
-  using page_load_metrics::EventOccurredInForeground;
+  using page_load_metrics::WasStartedInForegroundEventInForeground;
 
   if (!is_interesting_domain_)
     return;
 
-  if (EventOccurredInForeground(timing.load_event_start, extra_info)) {
+  if (WasStartedInForegroundEventInForeground(timing.load_event_start,
+                                              extra_info)) {
     PAGE_LOAD_HISTOGRAM(
         "PageLoad.Clients.StaleWhileRevalidateExperiment.Timing2."
         "NavigationToLoadEventFired",
         timing.load_event_start);
   }
-  if (EventOccurredInForeground(timing.first_layout, extra_info)) {
+  if (WasStartedInForegroundEventInForeground(timing.first_layout,
+                                              extra_info)) {
     PAGE_LOAD_HISTOGRAM(
         "PageLoad.Clients.StaleWhileRevalidateExperiment.Timing2."
         "NavigationToFirstLayout",
         timing.first_layout);
   }
-  if (EventOccurredInForeground(timing.first_text_paint, extra_info)) {
+  if (WasStartedInForegroundEventInForeground(timing.first_text_paint,
+                                              extra_info)) {
     PAGE_LOAD_HISTOGRAM(
         "PageLoad.Clients.StaleWhileRevalidateExperiment.Timing2."
         "NavigationToFirstTextPaint",
         timing.first_text_paint);
   }
 }
 
 }  // namespace chrome