[page_load_metrics] Log cache warmth ratios at parse stop

chrome/browser/page_load_metrics/page_load_metrics_observer.h

Index: chrome/browser/page_load_metrics/page_load_metrics_observer.h
diff --git a/chrome/browser/page_load_metrics/page_load_metrics_observer.h b/chrome/browser/page_load_metrics/page_load_metrics_observer.h
index 52e282644676b2e1e5ffd47a0ebeddc3adac33b1..af8d1971871384282c8766c120abcfc015fd3b0d 100644
--- a/chrome/browser/page_load_metrics/page_load_metrics_observer.h
+++ b/chrome/browser/page_load_metrics/page_load_metrics_observer.h
@@ -69,6 +69,8 @@ struct PageLoadExtraInfo {
       const base::Optional<base::TimeDelta>& time_to_commit,
       UserAbortType abort_type,
       const base::Optional<base::TimeDelta>& time_to_abort,
+      int num_cache_requests,
+      int num_network_requests,
       const PageLoadMetadata& metadata);
 
   PageLoadExtraInfo(const PageLoadExtraInfo& other);
@@ -97,6 +99,12 @@ struct PageLoadExtraInfo {
 
   const base::Optional<base::TimeDelta> time_to_abort;
 
+  // Note: these are only approximations, based on WebContents attribution from
+  // ResourceRequestInfo objects while this is the currently committed load in
+  // the WebContents.
+  int num_cache_requests;
+  int num_network_requests;
+
   // Extra information supplied to the page load metrics system from the
   // renderer.
   const PageLoadMetadata metadata;