Report page load timing information for child frames.

chrome/browser/page_load_metrics/page_load_metrics_observer.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_
 #define CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 252 matching lines @@
   // callbacks to indicate whether the observer would like to continue observing
   // metric callbacks. Observers that wish to continue observing metric
   // callbacks should return CONTINUE_OBSERVING; observers that wish to stop
   // observing callbacks should return STOP_OBSERVING. Observers that return
   // STOP_OBSERVING may be deleted.
   enum ObservePolicy {
     CONTINUE_OBSERVING,
     STOP_OBSERVING,
   };
 
+  typedef int FrameTreeNodeId;

[jkarlin, 2017/05/08 13:00:41]

using FrameTreeNodeId = int;

[Bryan McQuade, 2017/05/08 15:26:32]

Done

+
   virtual ~PageLoadMetricsObserver() {}
 
   // The page load started, with the given navigation handle.
   // currently_committed_url contains the URL of the committed page load at the
   // time the navigation for navigation_handle was initiated, or the empty URL
   // if there was no committed page load at the time the navigation was
   // initiated.
   virtual ObservePolicy OnStart(content::NavigationHandle* navigation_handle,
                                 const GURL& currently_committed_url,
                                 bool started_in_foreground);
@@ skipping 45 matching lines @@
   // callbacks below.
 
   // OnTimingUpdate is triggered when an updated PageLoadTiming is
   // available. This method may be called multiple times over the course of the
   // page load. This method is currently only intended for use in testing. Most
   // implementers should implement one of the On* callbacks, such as
   // OnFirstContentfulPaint or OnDomContentLoadedEventStart. Please email
   // loading-dev@chromium.org if you intend to override this method.
   virtual void OnTimingUpdate(const PageLoadTiming& timing,
                               const PageLoadExtraInfo& extra_info) {}
+
+  // OnSubFrameTimingUpdate is triggered when an updated PageLoadTiming or
+  // PageLoadMetadata is available for a child frame of the current page

[jkarlin, 2017/05/08 13:00:41]

Need ||'s around the argument names.

[Bryan McQuade, 2017/05/08 15:26:32]

Done

+  // load. The FrameTreeNodeId identifies the frame that navigation_start,
+  // child_timing, and child_metadata are associated with. The PageLoadExtraInfo
+  // contains the extra info associated with the page. navigation_start_offset
+  // reports the offset of the subframe's navigation start from the main frame's
+  // navigation_start. The timings reported in child_timing are relative to the
+  // frame's navigation_start.
+  virtual void OnSubFrameTimingUpdate(FrameTreeNodeId child_frame_id,
+                                      base::TimeDelta navigation_start_offset,
+                                      const PageLoadTiming& child_timing,
+                                      const PageLoadMetadata& child_metadata,
+                                      const PageLoadExtraInfo& extra_info) {}
+
   // OnUserInput is triggered when a new user input is passed in to
   // web_contents. Contains a TimeDelta from navigation start.
   virtual void OnUserInput(const blink::WebInputEvent& event) {}
 
   // The following methods are invoked at most once, when the timing for the
   // associated event first becomes available.
   virtual void OnDomContentLoadedEventStart(
       const PageLoadTiming& timing,
       const PageLoadExtraInfo& extra_info) {}
   virtual void OnLoadEventStart(const PageLoadTiming& timing,
@@ skipping 78 matching lines @@
   // Called whenever a request is loaded for this page load. This comes
   // unfiltered from the ResourceDispatcherHost and may include blob requests
   // and data uris.
   virtual void OnLoadedResource(
       const ExtraRequestCompleteInfo& extra_request_complete_info) {}
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_