Report page load timing information for child frames.

chrome/browser/page_load_metrics/page_load_tracker.h

Index: chrome/browser/page_load_metrics/page_load_tracker.h
diff --git a/chrome/browser/page_load_metrics/page_load_tracker.h b/chrome/browser/page_load_metrics/page_load_tracker.h
index f6529d1a059d00a620572763477253d17ed8fec0..364c620d41e1b9bc23eec6007bdcac5638fe162e 100644
--- a/chrome/browser/page_load_metrics/page_load_tracker.h
+++ b/chrome/browser/page_load_metrics/page_load_tracker.h
@@ -222,10 +222,14 @@ class PageLoadTracker {
   void UpdateTiming(const PageLoadTiming& timing,
                     const PageLoadMetadata& metadata);
 
+  void UpdateSubFrameTiming(content::RenderFrameHost* render_frame_host,
+                            const PageLoadTiming& new_timing,
+                            const PageLoadMetadata& new_metadata);
+
   // Update metadata for child frames. Updates for child frames arrive
   // separately from updates for the main frame, so aren't included in
   // UpdateTiming.
-  void UpdateChildFrameMetadata(const PageLoadMetadata& child_metadata);
+  void UpdateSubFrameMetadata(const PageLoadMetadata& child_metadata);
 
   void OnStartedResource(
       const ExtraRequestStartInfo& extra_request_started_info);
@@ -306,6 +310,8 @@ class PageLoadTracker {
                                  base::TimeDelta actual_delay);
 
  private:
+  typedef int FrameTreeNodeId;
+
   // This function converts a TimeTicks value taken in the browser process
   // to navigation_start_ if:
   // - base::TimeTicks is not comparable across processes because the clock
@@ -403,6 +409,10 @@ class PageLoadTracker {
 
   std::vector<std::unique_ptr<PageLoadMetricsObserver>> observers_;
 
+  // Navigation start offsets for the most recently committed document in each
+  // frame.
+  std::map<FrameTreeNodeId, base::TimeDelta> child_frame_navigation_start_;
+
   DISALLOW_COPY_AND_ASSIGN(PageLoadTracker);
 };