Histogram the amount of time spent on HTTP(S) page loads

components/page_load_metrics/browser/metrics_web_contents_observer.cc

Index: components/page_load_metrics/browser/metrics_web_contents_observer.cc
diff --git a/components/page_load_metrics/browser/metrics_web_contents_observer.cc b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
index c5705732f61144dcebb8424f6531183a7ea0638a..afa030ded70aec9461b5307eff0c383e0e20336d 100644
--- a/components/page_load_metrics/browser/metrics_web_contents_observer.cc
+++ b/components/page_load_metrics/browser/metrics_web_contents_observer.cc
@@ -301,6 +301,9 @@ void PageLoadTracker::WebContentsHidden() {
     DCHECK_EQ(started_in_foreground_, foreground_time_.is_null());
     background_time_ = base::TimeTicks::Now();
   }
+
+  for (const auto& observer : observers_)
+    observer->OnHidden();
 }
 
 void PageLoadTracker::WebContentsShown() {
@@ -312,6 +315,9 @@ void PageLoadTracker::WebContentsShown() {
     DCHECK_NE(started_in_foreground_, background_time_.is_null());
     foreground_time_ = base::TimeTicks::Now();
   }
+
+  for (const auto& observer : observers_)
+    observer->OnShown();
 }
 
 void PageLoadTracker::Commit(content::NavigationHandle* navigation_handle) {
@@ -320,7 +326,7 @@ void PageLoadTracker::Commit(content::NavigationHandle* navigation_handle) {
   commit_time_ = base::TimeTicks::Now();
   url_ = navigation_handle->GetURL();
   for (const auto& observer : observers_) {
-    observer->OnCommit(navigation_handle);
+    observer->OnCommit(navigation_handle, started_in_foreground_);
   }
   LogAbortChainHistograms(navigation_handle);
 }