Send an event to the page load metrics to track resource starting.

chrome/browser/page_load_metrics/page_load_tracker.cc

Index: chrome/browser/page_load_metrics/page_load_tracker.cc
diff --git a/chrome/browser/page_load_metrics/page_load_tracker.cc b/chrome/browser/page_load_metrics/page_load_tracker.cc
index 130f23f2a0e00f85647bbb822395478d35bf4bd8..661c046751793918b18e79f79c6cd328e6bbcb7a 100644
--- a/chrome/browser/page_load_metrics/page_load_tracker.cc
+++ b/chrome/browser/page_load_metrics/page_load_tracker.cc
@@ -584,8 +584,15 @@ void PageLoadTracker::UpdateTiming(const PageLoadTiming& new_timing,
   }
 }
 
+void PageLoadTracker::OnStartedResource(
+    const ExtraRequestStartInfo& extra_request_info) {
+  for (const auto& observer : observers_) {
+    observer->OnStartedResource(extra_request_info);
+  }
+}
+
 void PageLoadTracker::OnLoadedResource(
-    const ExtraRequestInfo& extra_request_info) {
+    const ExtraRequestCompleteInfo& extra_request_info) {
   for (const auto& observer : observers_) {
     observer->OnLoadedResource(extra_request_info);
   }