Revert "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
deleted file mode 100644
index e9be0ccf5dbc58d2e1bda2931b97756d77b5bd92..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/html/AutoplayUmaHelper.cpp
+++ /dev/null
@@ -1,112 +0,0 @@
-// 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/events/Event.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);
-}
-
-} // namespace
-
-AutoplayUmaHelper* AutoplayUmaHelper::create(HTMLMediaElement* element)
-{
-    return new AutoplayUmaHelper(element);
-}
-
-AutoplayUmaHelper::AutoplayUmaHelper(HTMLMediaElement* element)
-    : EventListener(CPPEventListenerType)
-    , m_source(AutoplaySource::NumberOfSources)
-    , m_element(element)
-    , m_videoMutedPlayMethodVisibilityObserver(nullptr) { }
-
-AutoplayUmaHelper::~AutoplayUmaHelper() = default;
-
-bool AutoplayUmaHelper::operator==(const EventListener& other) const
-{
-    return this == &other;
-}
-
-void AutoplayUmaHelper::onAutoplayInitiated(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)));
-
-    m_source = source;
-
-    if (m_element->isHTMLVideoElement()) {
-        videoHistogram.count(static_cast<int>(m_source));
-        if (m_element->muted())
-            mutedVideoHistogram.count(static_cast<int>(m_source));
-    } else {
-        audioHistogram.count(static_cast<int>(m_source));
-    }
-
-    if (m_source == AutoplaySource::Method && m_element->isHTMLVideoElement() && m_element->muted())
-        m_element->addEventListener(EventTypeNames::playing, this, false);
-}
-
-void AutoplayUmaHelper::onElementDestroyed()
-{
-    if (m_videoMutedPlayMethodVisibilityObserver) {
-        recordVideoAutoplayMutedPlayMethodBecomesVisibleUma(false);
-        m_videoMutedPlayMethodVisibilityObserver->stop();
-        m_videoMutedPlayMethodVisibilityObserver = nullptr;
-    }
-}
-
-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));
-}
-
-void AutoplayUmaHelper::onVisibilityChangedForVideoMutedPlayMethod(bool isVisible)
-{
-    if (!isVisible)
-        return;
-
-    recordVideoAutoplayMutedPlayMethodBecomesVisibleUma(true);
-    m_videoMutedPlayMethodVisibilityObserver->stop();
-    m_videoMutedPlayMethodVisibilityObserver = nullptr;
-}
-
-void AutoplayUmaHelper::handleEvent(ExecutionContext* executionContext, Event* event)
-{
-    DCHECK(event->type() == EventTypeNames::playing);
-    handlePlayingEvent();
-}
-
-void AutoplayUmaHelper::handlePlayingEvent()
-{
-    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();
-        }
-    }
-    m_element->removeEventListener(EventTypeNames::playing, this, false);
-}
-
-DEFINE_TRACE(AutoplayUmaHelper)
-{
-    EventListener::trace(visitor);
-    visitor->trace(m_element);
-    visitor->trace(m_videoMutedPlayMethodVisibilityObserver);
-}
-
-} // namespace blink