Measure whether muted videos that started playing with play() become visible at some point

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

Index: third_party/WebKit/Source/core/html/AutoplayUmaHelper.cpp
diff --git a/third_party/WebKit/Source/core/html/AutoplayUmaHelper.cpp b/third_party/WebKit/Source/core/html/AutoplayUmaHelper.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..2a09643549a6bde34bcd54b648a2881a7e85473b
--- /dev/null
+++ b/third_party/WebKit/Source/core/html/AutoplayUmaHelper.cpp
@@ -0,0 +1,100 @@
+// 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/ElementVisibilityObserver.h"
+#include "core/html/HTMLMediaElement.h"
+#include "platform/Histogram.h"
+
+namespace blink {
+
+namespace {
+
+void recordVideoAutoplayMutedPlayMethodBecomesVisibleUma(bool visible)
+{
+    DEFINE_STATIC_LOCAL(BooleanHistogram, histogram, ("Media.Video.Autoplay.Muted.PlayMethod.BecomesVisible"));
+    histogram.count(visible);
+}
+
+void recordAutoplaySourceUma(HTMLMediaElement* element, AutoplaySource source)
+{
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, videoHistogram, ("Media.Video.Autoplay", static_cast<int>(AutoplaySource::NumberOfSources)));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, mutedVideoHistogram, ("Media.Video.Autoplay.Muted", static_cast<int>(AutoplaySource::NumberOfSources)));
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, audioHistogram, ("Media.Audio.Autoplay", static_cast<int>(AutoplaySource::NumberOfSources)));
+
+    if (element->isHTMLVideoElement()) {
+        videoHistogram.count(static_cast<int>(source));
+        if (element->muted())
+            mutedVideoHistogram.count(static_cast<int>(source));
+    } else {
+        audioHistogram.count(static_cast<int>(source));
+    }
+}
+
+void recordAutoplayUnmuteStatus(AutoplayUnmuteActionStatus status)
+{
+    DEFINE_STATIC_LOCAL(EnumerationHistogram, autoplayUnmuteHistogram, ("Media.Video.Autoplay.Muted.UnmuteAction", AutoplayUnmuteActionStatus::NumberOfStatus));
+
+    autoplayUnmuteHistogram.count(status);
+}
+
+} // namespace
+
+AutoplayUmaHelper::AutoplayUmaHelper(HTMLMediaElement* element)
+    : m_source(AutoplaySource::NumberOfSources)
+    , m_element(element)
+    , m_videoMutedPlayMethodVisibilityObserver(nullptr)
+{
+}
+
+AutoplayUmaHelper::~AutoplayUmaHelper() = default;
+
+void AutoplayUmaHelper::onAutoplayInitiated(AutoplaySource source)
+{
+    m_source = source;
+    recordAutoplaySourceUma(m_element, m_source);
+}
+
+void AutoplayUmaHelper::onAutoplayStarted()
+{
+    if (m_source == AutoplaySource::Method && m_element->isHTMLVideoElement() && m_element->muted()) {
+        if (!m_videoMutedPlayMethodVisibilityObserver) {
+            m_videoMutedPlayMethodVisibilityObserver = new ElementVisibilityObserver(m_element, WTF::bind(&AutoplayUmaHelper::onVisibilityChangedForVideoMutedPlayMethod, wrapPersistent(this)));
+            m_videoMutedPlayMethodVisibilityObserver->start();
+        }
+    }
+}
+
+void AutoplayUmaHelper::onElementDestroyed()
+{
+    if (m_videoMutedPlayMethodVisibilityObserver) {
+        recordVideoAutoplayMutedPlayMethodBecomesVisibleUma(false);
+        m_videoMutedPlayMethodVisibilityObserver->stop();
+        m_videoMutedPlayMethodVisibilityObserver = nullptr;
+    }
+}
+
+void AutoplayUmaHelper::recordAutoplayUnmuteStatus(AutoplayUnmuteActionStatus status)
+{
+    blink::recordAutoplayUnmuteStatus(status);
+}
+
+void AutoplayUmaHelper::onVisibilityChangedForVideoMutedPlayMethod(bool isVisible)
+{
+    if (!isVisible)
+        return;
+
+    recordVideoAutoplayMutedPlayMethodBecomesVisibleUma(true);
+    m_videoMutedPlayMethodVisibilityObserver->stop();
+    m_videoMutedPlayMethodVisibilityObserver = nullptr;
+}
+
+DEFINE_TRACE(AutoplayUmaHelper)
+{
+    visitor->trace(m_element);
+    visitor->trace(m_videoMutedPlayMethodVisibilityObserver);
+}
+
+} // namespace blink