Refactor PageLoadMetricsObserver completion callback policy

chrome/browser/page_load_metrics/observers/core_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_OBSERVERS_CORE_PAGE_LOAD_METRICS_OBSERVER_H_
 #define CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_CORE_PAGE_LOAD_METRICS_OBSERVER_H_
 
 #include "components/page_load_metrics/browser/page_load_metrics_observer.h"
 
 namespace internal {
@@ skipping 70 matching lines @@
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
   void OnParseStart(
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
   void OnParseStop(
       const page_load_metrics::PageLoadTiming& timing,
       const page_load_metrics::PageLoadExtraInfo& extra_info) override;
   void OnComplete(const page_load_metrics::PageLoadTiming& timing,
                   const page_load_metrics::PageLoadExtraInfo& info) override;
   void OnFailedProvisionalLoad(
-      content::NavigationHandle* navigation_handle) override;
+      const page_load_metrics::FailedProvisionalLoadInfo& failed_load_info,
+      const page_load_metrics::PageLoadExtraInfo& extra_info) override;
 
  private:
-  // Information related to failed provisional loads.
-  // Populated in OnFailedProvisionalLoad and accessed in OnComplete.
-  struct FailedProvisionalLoadInfo {
-    base::Optional<base::TimeDelta> interval;
-    net::Error error;
-
-    FailedProvisionalLoadInfo();
-    ~FailedProvisionalLoadInfo();
-  };
-
   void RecordTimingHistograms(const page_load_metrics::PageLoadTiming& timing,
                               const page_load_metrics::PageLoadExtraInfo& info);
   void RecordRappor(const page_load_metrics::PageLoadTiming& timing,
                     const page_load_metrics::PageLoadExtraInfo& info);
 
-  FailedProvisionalLoadInfo failed_provisional_load_info_;
   ui::PageTransition transition_;
   bool initiated_by_user_gesture_;
 
   DISALLOW_COPY_AND_ASSIGN(CorePageLoadMetricsObserver);
 };
 
 #endif  // CHROME_BROWSER_PAGE_LOAD_METRICS_OBSERVERS_CORE_PAGE_LOAD_METRICS_OBSERVER_H_