[page_load_metrics] Add a NavigationThrottle for richer abort metrics

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 "base/macros.h"
 #include "base/optional.h"
 #include "chrome/common/page_load_metrics/page_load_timing.h"
@@ skipping 24 matching lines @@
   ABORT_STOP,
 
   // If the navigation is aborted by closing the tab or browser.
   ABORT_CLOSE,
 
   // We don't know why the navigation aborted. This is the value we assign to an
   // aborted load if the only signal we get is a provisional load finishing
   // without committing, either without error or with net::ERR_ABORTED.
   ABORT_OTHER,
 
-  // The load aborted due to another navigation, but it isn't clear what type of
-  // navigation it was.
-  ABORT_UNKNOWN_NAVIGATION,
-
   // Add values before this final count.
   ABORT_LAST_ENTRY
 };
 
 // Information related to failed provisional loads.
 struct FailedProvisionalLoadInfo {
   FailedProvisionalLoadInfo(base::TimeDelta interval, net::Error error);
   ~FailedProvisionalLoadInfo();
 
   base::TimeDelta time_to_failed_provisional_load;
@@ skipping 27 matching lines @@
   // Committed URL. If the page load did not commit, |committed_url| will be
   // empty.
   const GURL committed_url;
 
   // Time from navigation start until commit.
   const base::Optional<base::TimeDelta> time_to_commit;
 
   // The abort time and time to abort for this page load. If the page was not
   // aborted, |abort_type| will be |ABORT_NONE|.
   const UserAbortType abort_type;
+
   const base::Optional<base::TimeDelta> time_to_abort;
 
   // Extra information supplied to the page load metrics system from the
   // renderer.
   const PageLoadMetadata metadata;
 };
 
 // Interface for PageLoadMetrics observers. All instances of this class are
 // owned by the PageLoadTracker tracking a page load.
 class PageLoadMetricsObserver {
@@ skipping 97 matching lines @@
   // loads that result in downloads or 204s are aborted by the system, and are
   // also included as failed provisional loads.
   virtual void OnFailedProvisionalLoad(
       const FailedProvisionalLoadInfo& failed_provisional_load_info,
       const PageLoadExtraInfo& extra_info) {}
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_PAGE_LOAD_METRICS_OBSERVER_H_