Plumb experiment flags through page_load_metrics and add a new observer

components/page_load_metrics/browser/metrics_web_contents_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 COMPONENTS_PAGE_LOAD_METRICS_BROWSER_METRICS_WEB_CONTENTS_OBSERVER_H_
 #define COMPONENTS_PAGE_LOAD_METRICS_BROWSER_METRICS_WEB_CONTENTS_OBSERVER_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 102 matching lines @@
                   int aborted_chain_size,
                   int aborted_chain_size_same_url);
   ~PageLoadTracker();
   void Redirect(content::NavigationHandle* navigation_handle);
   void Commit(content::NavigationHandle* navigation_handle);
   void FailedProvisionalLoad(content::NavigationHandle* navigation_handle);
   void WebContentsHidden();
   void WebContentsShown();
 
   // Returns true if the timing was successfully updated.
-  bool UpdateTiming(const PageLoadTiming& timing);
+  bool UpdateTiming(const PageLoadTiming& timing,
+                    const PageLoadMetadata& metadata);
   bool HasBackgrounded();
 
   void set_renderer_tracked(bool renderer_tracked);
   bool renderer_tracked() const { return renderer_tracked_; }
 
   int aborted_chain_size() const { return aborted_chain_size_; }
   int aborted_chain_size_same_url() const {
     return aborted_chain_size_same_url_;
   }
 
@@ skipping 51 matching lines @@
   base::TimeTicks abort_time_;
 
   // We record separate metrics for events that occur after a background,
   // because metrics like layout/paint are delayed artificially
   // when they occur in the background.
   base::TimeTicks background_time_;
   base::TimeTicks foreground_time_;
   bool started_in_foreground_;
 
   PageLoadTiming timing_;
+  PageLoadMetadata metadata_;
 
   // This is a subtle member. If a provisional load A gets aborted by
   // provisional load B, which gets aborted by C that eventually commits, then
   // there exists an abort chain of length 2, starting at A's navigation_start.
   // This is useful because it allows histograming abort chain lengths based on
   // what the last load's transition type is. i.e. holding down F-5 to spam
   // reload will produce a long chain with the RELOAD transition.
   const int aborted_chain_size_;
 
   // This member counts consecutive provisional aborts that share a url. It will
@@ skipping 46 matching lines @@
   void NotifyAbortAllLoads(UserAbortType abort_type);
   void NotifyAbortAllLoadsWithTimestamp(UserAbortType abort_type,
                                         base::TimeTicks timestamp);
   // Notify aborted provisional loads that a new navigation occurred. This is
   // used for more consistent attribution tracking for aborted provisional
   // loads. This method returns the provisional load that was likely aborted by
   // this navigation, to help instantiate the new PageLoadTracker.
   scoped_ptr<PageLoadTracker> NotifyAbortedProvisionalLoadsNewNavigation(
       content::NavigationHandle* new_navigation);
 
-  void OnTimingUpdated(content::RenderFrameHost*, const PageLoadTiming& timing);
+  void OnTimingUpdated(content::RenderFrameHost*,
+                       const PageLoadTiming& timing,
+                       const PageLoadMetadata& metadata);
 
   // True if the web contents is currently in the foreground.
   bool in_foreground_;
 
   // The PageLoadTrackers must be deleted before the |embedded_interface_|,
   // because they hold a pointer to the |embedder_interface_|.
   scoped_ptr<PageLoadMetricsEmbedderInterface> embedder_interface_;
 
   // This map tracks all of the navigations ongoing that are not committed
   // yet. Once a navigation is committed, it moves from the map to
@@ skipping 10 matching lines @@
   std::vector<scoped_ptr<PageLoadTracker>> aborted_provisional_loads_;
 
   scoped_ptr<PageLoadTracker> committed_load_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsWebContentsObserver);
 };
 
 }  // namespace page_load_metrics
 
 #endif  // COMPONENTS_PAGE_LOAD_METRICS_BROWSER_METRICS_WEB_CONTENTS_OBSERVER_H_