Add support for tracking loading behavior of child frames.

chrome/browser/page_load_metrics/observers/css_scanning_page_load_metrics_observer.cc

Index: chrome/browser/page_load_metrics/observers/css_scanning_page_load_metrics_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/css_scanning_page_load_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/css_scanning_page_load_metrics_observer.cc
index e29a4dddf80d95527689e1b14a8d5676605d2e4f..b27188a1543e27bd60912aff7653687d4cba3093 100644
--- a/chrome/browser/page_load_metrics/observers/css_scanning_page_load_metrics_observer.cc
+++ b/chrome/browser/page_load_metrics/observers/css_scanning_page_load_metrics_observer.cc
@@ -14,7 +14,7 @@ CssScanningMetricsObserver::~CssScanningMetricsObserver() {}
 void CssScanningMetricsObserver::OnFirstContentfulPaint(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
-  if (info.metadata.behavior_flags &
+  if (info.main_frame_metadata.behavior_flags &

[Charlie Harrison, 2017/03/09 16:21:28]

This class probably also wants to observe all cases where this happens.

[Bryan McQuade, 2017/03/09 17:36:32]

ah, excellent, i wasn't sure, thanks! will update it.

           blink::WebLoadingBehaviorFlag::WebLoadingBehaviorCSSPreloadFound &&
       WasStartedInForegroundOptionalEventInForeground(
           timing.first_contentful_paint, info)) {
@@ -28,7 +28,7 @@ void CssScanningMetricsObserver::OnFirstContentfulPaint(
 void CssScanningMetricsObserver::OnFirstMeaningfulPaint(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& info) {
-  if (info.metadata.behavior_flags &
+  if (info.main_frame_metadata.behavior_flags &
           blink::WebLoadingBehaviorFlag::WebLoadingBehaviorCSSPreloadFound &&
       WasStartedInForegroundOptionalEventInForeground(
           timing.first_meaningful_paint, info)) {