Refactor PageLoadMetricsObserver completion callback policy

chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.cc

 // 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.
 
 #include "chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.h"
 
 #include "components/page_load_metrics/browser/page_load_metrics_util.h"
 
 using page_load_metrics::UserAbortType;
 
@@ skipping 149 matching lines @@
       NOTREACHED() << "Received UserAbortType::ABORT_OTHER for committed load.";
       return;
     case UserAbortType::ABORT_NONE:
     case UserAbortType::ABORT_LAST_ENTRY:
       NOTREACHED();
       return;
   }
   NOTREACHED();
 }
 
+bool ShouldTrackMetrics(
+    const page_load_metrics::PageLoadExtraInfo& extra_info) {
+  UserAbortType abort_type = extra_info.abort_type;
+  if (abort_type == UserAbortType::ABORT_NONE)
+    return false;
+
+  DCHECK(extra_info.time_to_abort);
+
+  // Don't log abort times if the page was backgrounded before the abort event.
+  if (!WasStartedInForegroundOptionalEventInForeground(extra_info.time_to_abort,
+                                                       extra_info))
+    return false;
+
+  return true;
+}
+
 }  // namespace
 
 AbortsPageLoadMetricsObserver::AbortsPageLoadMetricsObserver() {}
 
 void AbortsPageLoadMetricsObserver::OnComplete(
     const page_load_metrics::PageLoadTiming& timing,
     const page_load_metrics::PageLoadExtraInfo& extra_info) {
-  UserAbortType abort_type = extra_info.abort_type;
-  if (abort_type == UserAbortType::ABORT_NONE)
+  if (!ShouldTrackMetrics(extra_info))
     return;
 
-  DCHECK(extra_info.time_to_abort);
-
-  // Don't log abort times if the page was backgrounded before the abort event.
-  if (!WasStartedInForegroundOptionalEventInForeground(extra_info.time_to_abort,
-                                                       extra_info))
+  // If we did not receive any timing IPCs from the render process, we can't
+  // know for certain if the page was truly aborted before paint, or if the
+  // abort happened before we received the IPC from the render process. Thus, we
+  // do not log aborts for these page loads. Tracked page loads that receive no
+  // timing IPCs are tracked via the ERR_NO_IPCS_RECEIVED error code in the
+  // PageLoad.Events.InternalError histogram, so we can keep track of how often
+  // this happens.
+  if (timing.IsEmpty())
     return;
 
   const base::TimeDelta& time_to_abort = extra_info.time_to_abort.value();
+  if (timing.parse_start && time_to_abort >= timing.parse_start &&
+      (!timing.parse_stop || timing.parse_stop >= time_to_abort)) {
+    RecordAbortDuringParse(extra_info.abort_type, time_to_abort);
+  }
+  if (!timing.first_paint || timing.first_paint >= time_to_abort) {
+    RecordAbortAfterCommitBeforePaint(extra_info.abort_type, time_to_abort);
+  }
+}
 
-  if (!extra_info.time_to_commit) {
-    RecordAbortBeforeCommit(abort_type, time_to_abort);
-    return;
-  }
-
-  // If we have a committed load but |timing.IsEmpty()|, then this load was not
-  // tracked by the renderer. In this case, it is not possible to know whether
-  // the abort signals came before the page painted. Additionally, for
-  // consistency with PageLoad.(Document|Paint|Parse)Timing metrics recorded by
-  // the CorePageLoadMetricsObserver, we ignore non-render-tracked loads when
-  // tracking aborts after commit.
-  if (timing.IsEmpty())
+void AbortsPageLoadMetricsObserver::OnFailedProvisionalLoad(
+    const page_load_metrics::FailedProvisionalLoadInfo& failed_load_info,
+    const page_load_metrics::PageLoadExtraInfo& extra_info) {
+  if (!ShouldTrackMetrics(extra_info))
     return;
 
-  if (timing.parse_start && time_to_abort >= timing.parse_start &&
-      (!timing.parse_stop || timing.parse_stop >= time_to_abort)) {
-    RecordAbortDuringParse(abort_type, time_to_abort);
-  }
-  if (!timing.first_paint || timing.first_paint >= time_to_abort) {
-    RecordAbortAfterCommitBeforePaint(abort_type, time_to_abort);
-  }
+  RecordAbortBeforeCommit(extra_info.abort_type,
+                          extra_info.time_to_abort.value());
 }