Buffer cross frame paint timing updates.

chrome/browser/page_load_metrics/metrics_web_contents_observer.h

Index: chrome/browser/page_load_metrics/metrics_web_contents_observer.h
diff --git a/chrome/browser/page_load_metrics/metrics_web_contents_observer.h b/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
index 81b858b7a9e13e465fc7fe2b38b34a88846e8339..44872baf4f928e4f2d870e94a6f1d5f50857b1e6 100644
--- a/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
+++ b/chrome/browser/page_load_metrics/metrics_web_contents_observer.h
@@ -95,6 +95,7 @@ class MetricsWebContentsObserver
   void MediaStartedPlaying(
       const content::WebContentsObserver::MediaPlayerInfo& video_type,
       const content::WebContentsObserver::MediaPlayerId& id) override;
+  void WebContentsDestroyed() override;
 
   // These methods are forwarded from the MetricsNavigationThrottle.
   void WillStartNavigationRequest(content::NavigationHandle* navigation_handle);