Add page load abort metrics to PageLoadMetrics system

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"
 #include "components/page_load_metrics/common/page_load_timing.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
+#include "net/base/net_errors.h"
 
 namespace content {
 class NavigationHandle;
 class RenderFrameHost;
 }  // namespace content
 
 namespace IPC {
 class Message;
 }  // namespace IPC
 
 namespace page_load_metrics {
 
+enum PageLoadEvent {
+  PAGE_LOAD_STARTED,
+
+  // A provisional load is a load before it commits.

[Randy Smith (Not in Mondays), 2015/10/01 17:18:08]

Define commits?  I.e. (assuming I have the right definition) " ... before it
commits (i.e. before the first byte of data is received)."

[Charlie Harrison, 2015/10/01 17:58:17]

Done.

+  // A load failed before it was committed for any reason, e.g. from a user
+  // abort or a network timeout.
+  PAGE_LOAD_FAILED_PROVISIONAL,

[Randy Smith (Not in Mondays), 2015/10/01 17:18:08]

suggestion: I think "FAILED_BEFORE_COMMIT" would be clearer than
"FAILED_PROVISIONAL"?

[Charlie Harrison, 2015/10/01 17:58:17]

Done.

+
+  // A subset of PAGE_LOAD_FAILED_PROVISIONAL, this counts the specific failures
+  // due to user aborts.
+  PAGE_LOAD_ABORTED_PROVISIONAL,
+
+  // When a load is aborted anytime before the page's first layout, we increase
+  // this count. This includes all failed provisional loads.
+  PAGE_LOAD_ABORTED_BEFORE_FIRST_LAYOUT,
+
+  // We increase this count if a page load successfully has a layout.

[Randy Smith (Not in Mondays), 2015/10/01 17:18:09]

nit: "these counts"

[Charlie Harrison, 2015/10/01 17:58:17]

Done.

+  // Differentiate between loads that were backgrounded before first layout.

[Randy Smith (Not in Mondays), 2015/10/01 17:18:08]

Just confirming: If a page is backgrounded and then foregrounded before first
layout, it'll still go in the BG bucket?

[Charlie Harrison, 2015/10/01 17:58:17]

Yupp, I edited the comment.

+  PAGE_LOAD_SUCCESSFUL_FIRST_LAYOUT_FG,
+  PAGE_LOAD_SUCCESSFUL_FIRST_LAYOUT_BG,

[Randy Smith (Not in Mondays), 2015/10/01 17:18:08]

We historically discourage abbreviations in chromium, so I'd recommend
FG->FOREGROUND, BG->BACKGROUND

+
+  // Add values before this final count. Make sure you also update
+  // histograms.xml.

[Randy Smith (Not in Mondays), 2015/10/01 17:18:09]

Actually, the note about the link to histograms.xml should be before the enum,
and it should also warn people not to *remove* values without revving the
histogram name.

[Charlie Harrison, 2015/10/01 17:58:17]

Done.

+  PAGE_LOAD_LAST_ENTRY
+};
+
 class PageLoadTracker {
  public:
   explicit PageLoadTracker(bool in_foreground);
   ~PageLoadTracker();
   void Commit();
   void WebContentsHidden();
 
   // 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_;
@@ skipping 44 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_