[PageLoadMetrics] Record bytes usage per page

chrome/browser/page_load_metrics/metrics_web_contents_observer.cc

Index: chrome/browser/page_load_metrics/metrics_web_contents_observer.cc
diff --git a/chrome/browser/page_load_metrics/metrics_web_contents_observer.cc b/chrome/browser/page_load_metrics/metrics_web_contents_observer.cc
index 571ef104db8367353264a36aaef54403df502d26..0610fbe594f3e5bc23f255a55a2d4d26b6b2cc04 100644
--- a/chrome/browser/page_load_metrics/metrics_web_contents_observer.cc
+++ b/chrome/browser/page_load_metrics/metrics_web_contents_observer.cc
@@ -178,17 +178,16 @@ void MetricsWebContentsObserver::WillStartNavigationRequest(
 void MetricsWebContentsObserver::OnRequestComplete(
     content::ResourceType resource_type,
     bool was_cached,
-    int net_error) {
-  // For simplicity, only count subresources. Navigations are hard to attribute
-  // here because we won't have a committed load by the time data streams in
-  // from the IO thread.
-  if (resource_type == content::RESOURCE_TYPE_MAIN_FRAME &&
-      net_error != net::OK) {
+    int64_t raw_body_bytes,
+    base::TimeTicks creation_time) {
+  // If the navigation hasn't committed yet then we'll miss the resource (this

[Bryan McQuade, 2016/12/16 14:28:45]

let's maybe add a comment here noting some of the issues ryansturm points out
with races between renderers, and that we think it should be relatively rare,
but we may want to address it in a follow up CL.

[jkarlin, 2016/12/19 19:26:01]

Done.

+  // happens on the new tab page). Also, if the resource request was started
+  // before this navigation then it should be ignored.
+  if (!committed_load_ || creation_time < committed_load_->navigation_start()) {
     return;
   }
-  if (!committed_load_)
-    return;
-  committed_load_->OnLoadedSubresource(was_cached);
+
+  committed_load_->OnLoadedResource(was_cached, raw_body_bytes);
 }
 
 const PageLoadExtraInfo