Page Abort Events for relevant navigations

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_PAGE_LOAD_METRICS_WEB_CONTENTS_OBSERVER_H_
 #define COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_WEB_CONTENTS_OBSERVER_H_
 
 #include "base/containers/scoped_ptr_map.h"
 #include "base/macros.h"
 #include "base/time/time.h"
@@ skipping 34 matching lines @@
   // these counts. This includes all failed provisional loads.
   PAGE_LOAD_ABORTED_BEFORE_FIRST_LAYOUT,
 
   // We increase this count if a page load successfully has a layout.
   // Differentiate between loads that were backgrounded before first layout.
   // Note that a load that is backgrounded, then foregrounded before first
   // layout will still end up in the backgrounded bucket.
   PAGE_LOAD_SUCCESSFUL_FIRST_LAYOUT_FOREGROUND,
   PAGE_LOAD_SUCCESSFUL_FIRST_LAYOUT_BACKGROUND,
 
+  // The user aborted the page load before first layout, and the page is one
+  // that we would have logged first layout info from (e.g. it is http/https,
+  // not same-page, etc.).
+  PAGE_LOAD_RELEVANT_ABORTED_BEFORE_FIRST_LAYOUT,
+
+  // Counts the number of page loads started in foreground / background.
+  PAGE_LOAD_RELEVANT_STARTED_IN_FOREGROUND,
+  PAGE_LOAD_RELEVANT_STARTED_IN_BACKGROUND,
+
+  // A timing IPC was sent from the renderer that did not line up with previous
+  // data we've received (i.e. navigation start is different or the timing
+  // struct is somehow invalid).
+  PAGE_LOAD_BAD_IPC,

[Randy Smith (Not in Mondays), 2015/10/06 19:24:00]

I'd like the comments for these instances to make clear what overlap they have
with the other elements in the list; tracking what's disjoint, what's subset,
and what's just overlapping is getting hard.

Suggestion (up to you): Make separate histograms (and separate enums) where each
histogram has the property that each load shows up in only one bucket.  It might
make the bucket descriptions a bit confusing, but I think it would make analysis
and comparison much easier.

+
   // Add values before this final count.
   PAGE_LOAD_LAST_ENTRY
 };
 
 class PageLoadTracker {
  public:
   explicit PageLoadTracker(bool in_foreground);
   ~PageLoadTracker();
   void Commit();
   void WebContentsHidden();
+  void WebContentsShown();
 
   // Returns true if the timing was successfully updated.
   bool UpdateTiming(const PageLoadTiming& timing);
   void RecordEvent(PageLoadEvent event);
 
  private:
   void RecordTimingHistograms();
 
   bool has_commit_;
 
   // We record separate metrics for events that occur after a background,
   // because metrics like layout/paint are delayed artificially
   // when they occur in the bacground.
   base::TimeTicks background_time_;
+  base::TimeTicks foreground_time_;
   bool started_in_foreground_;
 
   PageLoadTiming timing_;
 
   DISALLOW_COPY_AND_ASSIGN(PageLoadTracker);
 };
 
 // MetricsWebContentsObserver logs page load UMA metrics based on
 // IPC messages received from a MetricsRenderFrameObserver.
 class MetricsWebContentsObserver
@@ skipping 34 matching lines @@
   base::ScopedPtrMap<content::NavigationHandle*, scoped_ptr<PageLoadTracker>>
       provisional_loads_;
   scoped_ptr<PageLoadTracker> committed_load_;
 
   DISALLOW_COPY_AND_ASSIGN(MetricsWebContentsObserver);
 };
 
 }  // namespace page_load_metrics
 
 #endif  // COMPONENTS_PAGE_LOAD_METRICS_BROWSER_PAGE_LOAD_METRICS_WEB_CONTENTS_OBSERVER_H_