[Page Load Metrics] Add mojom file to page load metrics.

chrome/browser/page_load_metrics/observers/prerender_page_load_metrics_observer.cc

Index: chrome/browser/page_load_metrics/observers/prerender_page_load_metrics_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/prerender_page_load_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/prerender_page_load_metrics_observer.cc
index 43d4d0d1a02a7925addd593dbcc5c0109ea594a0..16bae5e35d6a1a1322c2118fc61000ed75aeb567 100644
--- a/chrome/browser/page_load_metrics/observers/prerender_page_load_metrics_observer.cc
+++ b/chrome/browser/page_load_metrics/observers/prerender_page_load_metrics_observer.cc
@@ -62,17 +62,17 @@ PrerenderPageLoadMetricsObserver::OnCommit(
 }
 
 void PrerenderPageLoadMetricsObserver::OnFirstContentfulPaintInPage(
-    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::mojom::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& extra_info) {
   DCHECK(!start_ticks_.is_null());
   prerender_manager_->RecordPrerenderFirstContentfulPaint(
       extra_info.start_url, web_contents_, is_no_store_, was_hidden_,
-      start_ticks_ + *timing.paint_timing.first_contentful_paint);
+      start_ticks_ + *timing.paint_timing->first_contentful_paint);
 }
 
 page_load_metrics::PageLoadMetricsObserver::ObservePolicy
 PrerenderPageLoadMetricsObserver::OnHidden(
-    const page_load_metrics::PageLoadTiming& timing,
+    const page_load_metrics::mojom::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& extra_info) {
   was_hidden_ = true;
   return CONTINUE_OBSERVING;