[page_load_metrics] User Initiated Abort Tracking (Observer version)

chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.cc

Index: chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.cc
diff --git a/chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.cc b/chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.cc
new file mode 100644
index 0000000000000000000000000000000000000000..076c3fc778bfb67727f31774a96852f3c316690c
--- /dev/null
+++ b/chrome/browser/page_load_metrics/observers/aborts_page_load_metrics_observer.cc
@@ -0,0 +1,89 @@
+// 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;
+
+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)
+    return;
+
+  const base::TimeDelta& time_to_abort = extra_info.time_to_abort;
+  DCHECK(!time_to_abort.is_zero());
+
+  // Loads are not considered aborts if they painted before the abort event.
+  if (!timing.first_paint.is_zero() && timing.first_paint < time_to_abort)
+    return;
+
+  // Don't log abort times if the page was backgrounded before the abort event.
+  if (!DurationOccurredInForeground(time_to_abort, extra_info))
+    return;
+
+  // If |timing.IsEmpty()|, then this load was not tracked by the renderer. It
+  // is impossible to know whether the abort signals came before the page
+  // painted.
+  if (extra_info.has_commit && !timing.IsEmpty()) {
+    switch (abort_type) {
+      case UserAbortType::ABORT_RELOAD:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortReloadBeforePaint, time_to_abort);
+        break;
+      case UserAbortType::ABORT_FORWARD_BACK:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortForwardBackBeforePaint,
+                            time_to_abort);
+        break;
+      case UserAbortType::ABORT_NEW_NAVIGATION:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortNewNavigationBeforePaint,
+                            time_to_abort);
+        break;
+      case UserAbortType::ABORT_STOP:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortStopBeforePaint, time_to_abort);
+        break;
+      case UserAbortType::ABORT_CLOSE:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortCloseBeforePaint, time_to_abort);
+        break;
+      case UserAbortType::ABORT_OTHER:
+        DLOG(FATAL)
+            << "Received UserAbortType::ABORT_OTHER for committed load.";
+        break;
+      default:

[kinuko, 2015/12/11 12:24:27]

If we do return instead of break in above cases and also do following we don't
need to use default (so that we could get warning when the enum's updated
without updating this switch/case):

   ...
 case ABORT_NONE:
 case ABORT_LAST:
   NOTREACHED();
}
NOTREACHED();

Also we can make this if/else into if/early-return pattern

[Charlie Harrison, 2015/12/11 14:12:20]

Done.

+        NOTREACHED();
+        break;
+    }
+  } else {
+    DCHECK(timing.IsEmpty());
+    switch (abort_type) {
+      case UserAbortType::ABORT_RELOAD:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortReloadBeforeCommit, time_to_abort);
+        break;
+      case UserAbortType::ABORT_FORWARD_BACK:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortForwardBackBeforeCommit,
+                            time_to_abort);
+        break;
+      case UserAbortType::ABORT_NEW_NAVIGATION:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortNewNavigationBeforeCommit,
+                            time_to_abort);
+        break;
+      case UserAbortType::ABORT_STOP:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortStopBeforeCommit, time_to_abort);
+        break;
+      case UserAbortType::ABORT_CLOSE:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortCloseBeforePaint, time_to_abort);
+        break;
+      case UserAbortType::ABORT_OTHER:
+        PAGE_LOAD_HISTOGRAM(kHistogramAbortOtherBeforeCommit, time_to_abort);
+        break;
+      default:

[kinuko, 2015/12/11 12:24:27]

ditto, using default could be error-prone

[Charlie Harrison, 2015/12/11 14:12:20]

Done.

+        NOTREACHED();
+        break;
+    }
+  }
+}