Add support for tracking loading behavior of 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 <string>
 
 #include "base/macros.h"
@@ skipping 100 matching lines @@
       const base::Optional<base::TimeDelta>& first_background_time,
       const base::Optional<base::TimeDelta>& first_foreground_time,
       bool started_in_foreground,
       UserInitiatedInfo user_initiated_info,
       const GURL& url,
       const GURL& start_url,
       bool did_commit,
       PageEndReason page_end_reason,
       UserInitiatedInfo page_end_user_initiated_info,
       const base::Optional<base::TimeDelta>& page_end_time,
-      const PageLoadMetadata& metadata);
+      const PageLoadMetadata& main_frame_metadata,
+      const PageLoadMetadata& child_frame_metadata);
 
   // Simplified version of the constructor, intended for use in tests.
   static PageLoadExtraInfo CreateForTesting(const GURL& url,
                                             bool started_in_foreground);
 
   PageLoadExtraInfo(const PageLoadExtraInfo& other);
 
   ~PageLoadExtraInfo();
 
   // The time the navigation was initiated.
@@ skipping 47 matching lines @@
   // * the load of the main resource fails
   // * the page load is stopped
   // * the tab hosting the page is closed
   // * the render process hosting the page goes away
   // * a new navigation which later commits is initiated in the same tab
   // This field will not be set if the page is still active and hasn't yet
   // finished.
   const base::Optional<base::TimeDelta> page_end_time;
 
   // Extra information supplied to the page load metrics system from the
-  // renderer.
-  const PageLoadMetadata metadata;
+  // renderer for the main frame.
+  const PageLoadMetadata main_frame_metadata;
+
+  // PageLoadMetadata for child frames of the current page load.
+  const PageLoadMetadata child_frame_metadata;
 };
 
 // Container for various information about a request within a page load.
 struct ExtraRequestInfo {
   ExtraRequestInfo(bool was_cached,
                    int64_t raw_body_bytes,
                    bool data_reduction_proxy_used,
                    int64_t original_network_content_length);
 
   ExtraRequestInfo(const ExtraRequestInfo& other);
@@ skipping 106 matching lines @@
                                  const PageLoadExtraInfo& extra_info) {}
   virtual void OnFirstContentfulPaint(const PageLoadTiming& timing,
                                       const PageLoadExtraInfo& extra_info) {}
   virtual void OnFirstMeaningfulPaint(const PageLoadTiming& timing,
                                       const PageLoadExtraInfo& extra_info) {}
   virtual void OnParseStart(const PageLoadTiming& timing,
                             const PageLoadExtraInfo& extra_info) {}
   virtual void OnParseStop(const PageLoadTiming& timing,
                            const PageLoadExtraInfo& extra_info) {}
 
-  // Invoked when there is a change in PageLoadMetadata's behavior_flags.
+  // Invoked when there is a change in either the main_frame_metadata or the
+  // child_frame_metadata's loading behavior_flags.
   virtual void OnLoadingBehaviorObserved(
       const page_load_metrics::PageLoadExtraInfo& extra_info) {}
 
   // Invoked when the UMA metrics subsystem is persisting metrics as the
   // application goes into the background, on platforms where the browser
   // process may be killed after backgrounding (Android). Implementers should
   // persist any metrics that have been buffered in memory in this callback, as
   // the application may be killed at any time after this method is invoked
   // without further notification. Note that this may be called both for
   // provisional loads as well as committed loads. Implementations that only
@@ skipping 30 matching lines @@
       const FailedProvisionalLoadInfo& failed_provisional_load_info,
       const PageLoadExtraInfo& extra_info) {}
 
   // Called whenever a request is loaded for this page load.
   virtual void OnLoadedResource(const ExtraRequestInfo& extra_request_info) {}
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_