Adding previews information to PLM UKM

chrome/browser/page_load_metrics/metrics_web_contents_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/metrics_web_contents_observer.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
@@ skipping 647 matching lines @@
   if (observer_) {
     observer_->RemoveTestingObserver(this);
     observer_ = nullptr;
   }
 }
 
 void MetricsWebContentsObserver::TestingObserver::OnGoingAway() {
   observer_ = nullptr;
 }
 
+void MetricsWebContentsObserver::BroadcastEventToObservers(
+    const void* const event_key) {
+  if (committed_load_)
+    committed_load_->BroadcastEventToObservers(event_key);
+}
+
 }  // namespace page_load_metrics