Adding Rappor metrics for disabling cross-origin autoplay with sound experiment

third_party/WebKit/Source/core/html/AutoplayUmaHelper.cpp

 // Copyright 2016 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 "core/html/AutoplayUmaHelper.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ElementVisibilityObserver.h"
 #include "core/events/Event.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLMediaElement.h"
 #include "platform/Histogram.h"
+#include "public/platform/Platform.h"
 #include "wtf/CurrentTime.h"
 
 namespace blink {
 
 namespace {
 
 const int32_t maxOffscreenDurationUmaMS = 60 * 60 * 1000;
 const int32_t offscreenDurationUmaBucketCount = 50;
 
 }  // namespace
@@ skipping 63 matching lines @@
     } else if (dataSaverEnabled) {
       blockedMutedVideoHistogram.count(AutoplayBlockedReasonDataSaver);
     } else if (blockedBySetting) {
       blockedMutedVideoHistogram.count(AutoplayBlockedReasonSetting);
     }
   }
 
   m_element->addEventListener(EventTypeNames::playing, this, false);
 }
 
+void AutoplayUmaHelper::recordCrossOriginExperimentMetric(
+    AutoplayCrossOriginExperimentMetric metric) {
+  if (!m_element->isHTMLVideoElement())

[whywhat, 2016/11/29 21:42:04]

nit: Should we avoid calling this for non-video elements and turn this into a
DCHECK?

[Zhiqiang Zhang (Slow), 2016/11/30 17:30:52]

I think that would introduce a lot of duplicate if statements, so I prefer not.

+    return;
+  if (!m_element->isCrossOrigin())

[whywhat, 2016/11/29 21:42:04]

nit: ditto

+    return;
+  if (m_recordedCrossOriginExperimentMetrics.count(metric))

[whywhat, 2016/11/29 21:42:04]

nit: add a comment why we only record each result once (per element I assume)?

[Zhiqiang Zhang (Slow), 2016/11/30 17:30:52]

Done.

+    return;
+
+  switch (metric) {
+    case AutoplayCrossOriginExperimentMetric::AutoplayAllowed:
+      // Record metric
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOriginExperiment.Allowed.ChildFrame",
+          m_element->document().url());
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOriginExperiment.Allowed.TopLevelFrame",
+          m_element->document().topDocument().url());
+      break;
+    case AutoplayCrossOriginExperimentMetric::AutoplayBlocked:
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOriginExperiment.Blocked.ChildFrame",
+          m_element->document().url());
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOriginExperiment.Blocked.TopLevelFrame",
+          m_element->document().topDocument().url());
+      break;
+    case AutoplayCrossOriginExperimentMetric::PlayedWithGesture:
+      if (!m_recordedCrossOriginExperimentMetrics.count(

[whywhat, 2016/11/29 21:42:04]

nit: a comment would help why this check is here.

[Zhiqiang Zhang (Slow), 2016/11/30 17:30:52]

Done.

+              AutoplayCrossOriginExperimentMetric::AutoplayBlocked)) {
+        return;
+      }
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOriginExperiment.PlayedWithGesture.ChildFrame",
+          m_element->document().url());
+      Platform::current()->recordRapporURL(
+          "Media.Autoplay.CrossOriginExperiment.PlayedWithGesture."
+          "TopLevelFrame",
+          m_element->document().topDocument().url());
+      break;
+    default:
+      NOTREACHED();
+  }
+  m_recordedCrossOriginExperimentMetrics.insert(metric);

[whywhat, 2016/11/29 21:42:04]

nit: put this next to the check if the metric is already recorded since these
two are coupled logically?

[Zhiqiang Zhang (Slow), 2016/11/30 17:30:52]

Done.

+}
+
 void AutoplayUmaHelper::recordAutoplayUnmuteStatus(
     AutoplayUnmuteActionStatus status) {
   DEFINE_STATIC_LOCAL(
       EnumerationHistogram, autoplayUnmuteHistogram,
       ("Media.Video.Autoplay.Muted.UnmuteAction",
        static_cast<int>(AutoplayUnmuteActionStatus::NumberOfStatus)));
 
   autoplayUnmuteHistogram.count(static_cast<int>(status));
 }
 
@@ skipping 159 matching lines @@
 }
 
 DEFINE_TRACE(AutoplayUmaHelper) {
   EventListener::trace(visitor);
   visitor->trace(m_element);
   visitor->trace(m_mutedVideoPlayMethodVisibilityObserver);
   visitor->trace(m_mutedVideoOffscreenDurationVisibilityObserver);
 }
 
 }  // namespace blink