Deprecating AutoplayExperimentHelper

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

Index: third_party/WebKit/Source/core/html/AutoplayExperimentHelper.cpp
diff --git a/third_party/WebKit/Source/core/html/AutoplayExperimentHelper.cpp b/third_party/WebKit/Source/core/html/AutoplayExperimentHelper.cpp
deleted file mode 100644
index 5b775af1537c55c544e762dfcf2af6125164b0f8..0000000000000000000000000000000000000000
--- a/third_party/WebKit/Source/core/html/AutoplayExperimentHelper.cpp
+++ /dev/null
@@ -1,512 +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/AutoplayExperimentHelper.h"
-
-#include "core/dom/Document.h"
-#include "core/frame/Settings.h"
-#include "core/html/HTMLMediaElement.h"
-#include "core/page/Page.h"
-#include "platform/UserGestureIndicator.h"
-#include "platform/geometry/IntRect.h"
-
-namespace blink {
-
-using namespace HTMLNames;
-
-// Seconds to wait after a video has stopped moving before playing it.
-static const double kViewportTimerPollDelay = 0.5;
-
-AutoplayExperimentHelper::AutoplayExperimentHelper(Client* client)
-    : m_client(client),
-      m_mode(Mode::ExperimentOff),
-      m_playPending(false),
-      m_registeredWithLayoutObject(false),
-      m_wasInViewport(false),
-      m_autoplayMediaEncountered(false),
-      m_playbackStartedMetricRecorded(false),
-      m_waitingForAutoplayPlaybackStop(false),
-      m_recordedElement(false),
-      m_lastLocationUpdateTime(-std::numeric_limits<double>::infinity()),
-      m_viewportTimer(this, &AutoplayExperimentHelper::viewportTimerFired),
-      m_autoplayDeferredMetric(GesturelessPlaybackNotOverridden) {
-  m_mode = fromString(this->client().autoplayExperimentMode());
-
-  DVLOG_IF(3, isExperimentEnabled()) << "autoplay experiment set to " << m_mode;
-}
-
-AutoplayExperimentHelper::~AutoplayExperimentHelper() {}
-
-void AutoplayExperimentHelper::becameReadyToPlay() {
-  // Assuming that we're eligible to override the user gesture requirement,
-  // either play if we meet the visibility checks, or install a listener
-  // to wait for them to pass.  We do not actually start playback; our
-  // caller must do that.
-  autoplayMediaEncountered();
-
-  if (isEligible()) {
-    if (meetsVisibilityRequirements())
-      prepareToAutoplay(GesturelessPlaybackStartedByAutoplayFlagImmediately);
-    else
-      registerForPositionUpdatesIfNeeded();
-  }
-}
-
-void AutoplayExperimentHelper::playMethodCalled() {
-  // If a play is already pending, then do nothing.  We're already trying
-  // to play.  Similarly, do nothing if we're already playing.
-  if (m_playPending || !m_client->paused())
-    return;
-
-  if (!UserGestureIndicator::utilizeUserGesture()) {
-    autoplayMediaEncountered();
-
-    // Check for eligibility, but don't worry if playback is currently
-    // pending.  If we're still not eligible, then this play() will fail.
-    if (isEligible(IgnorePendingPlayback)) {
-      m_playPending = true;
-
-      // If we are able to override the gesture requirement now, then
-      // do so.  Otherwise, install an event listener if we need one.
-      // We do not actually start playback; play() will do that.
-      if (meetsVisibilityRequirements()) {
-        // Override the gesture and assume that play() will succeed.
-        prepareToAutoplay(GesturelessPlaybackStartedByPlayMethodImmediately);
-      } else {
-        // Wait for viewport visibility.
-        // TODO(liberato): if the autoplay is allowed soon enough, then
-        // it should still record *Immediately.  Otherwise, we end up
-        // here before the first layout sometimes, when the item is
-        // visible but we just don't know that yet.
-        registerForPositionUpdatesIfNeeded();
-      }
-    }
-  } else if (isLockedPendingUserGesture()) {
-    // If this media tried to autoplay, and we haven't played it yet, then
-    // record that the user provided the gesture to start it the first time.
-    if (m_autoplayMediaEncountered && !m_playbackStartedMetricRecorded)
-      recordAutoplayMetric(AutoplayManualStart);
-    // Don't let future gestureless playbacks affect metrics.
-    m_autoplayMediaEncountered = true;
-    m_playbackStartedMetricRecorded = true;
-    m_playPending = false;
-
-    unregisterForPositionUpdatesIfNeeded();
-  }
-}
-
-void AutoplayExperimentHelper::pauseMethodCalled() {
-  // Don't try to autoplay, if we would have.
-  m_playPending = false;
-  unregisterForPositionUpdatesIfNeeded();
-}
-
-void AutoplayExperimentHelper::loadMethodCalled() {
-  if (isLockedPendingUserGesture() &&
-      UserGestureIndicator::utilizeUserGesture()) {
-    recordAutoplayMetric(AutoplayEnabledThroughLoad);
-    unlockUserGesture(GesturelessPlaybackEnabledByLoad);
-  }
-}
-
-void AutoplayExperimentHelper::mutedChanged() {
-  // Mute changes are always allowed if this is unlocked.
-  if (!client().isLockedPendingUserGesture())
-    return;
-
-  // Changes with a user gesture are okay.
-  if (UserGestureIndicator::utilizeUserGesture())
-    return;
-
-  // If the mute state has changed to 'muted', then it's okay.
-  if (client().muted())
-    return;
-
-  // If nothing is playing, then changes are okay too.
-  if (client().paused())
-    return;
-
-  // Trying to unmute without a user gesture.
-
-  // If we don't care about muted state, then it's okay.
-  if (!enabled(IfMuted) && !(client().isCrossOrigin() && enabled(OrMuted)))
-    return;
-
-  // Unmuting isn't allowed, so pause.
-  client().pauseInternal();
-}
-
-void AutoplayExperimentHelper::registerForPositionUpdatesIfNeeded() {
-  // If we don't require that the player is in the viewport, then we don't
-  // need the listener.
-  if (!requiresViewportVisibility()) {
-    if (!enabled(IfPageVisible))
-      return;
-  }
-
-  m_client->setRequestPositionUpdates(true);
-
-  // Set this unconditionally, in case we have no layout object yet.
-  m_registeredWithLayoutObject = true;
-}
-
-void AutoplayExperimentHelper::unregisterForPositionUpdatesIfNeeded() {
-  if (m_registeredWithLayoutObject)
-    m_client->setRequestPositionUpdates(false);
-
-  // Clear this unconditionally so that we don't re-register if we didn't
-  // have a LayoutObject now, but get one later.
-  m_registeredWithLayoutObject = false;
-}
-
-void AutoplayExperimentHelper::positionChanged(const IntRect& visibleRect) {
-  // Something, maybe position, has changed.  If applicable, start a
-  // timer to look for the end of a scroll operation.
-  // Don't do much work here.
-  // Also note that we are called quite often, including when the
-  // page becomes visible.  That's why we don't bother to register
-  // for page visibility changes explicitly.
-  if (visibleRect.isEmpty())
-    return;
-
-  m_lastVisibleRect = visibleRect;
-
-  IntRect currentLocation = client().absoluteBoundingBoxRect();
-  if (currentLocation.isEmpty())
-    return;
-
-  bool inViewport = meetsVisibilityRequirements();
-
-  if (m_lastLocation != currentLocation) {
-    m_lastLocationUpdateTime = monotonicallyIncreasingTime();
-    m_lastLocation = currentLocation;
-  }
-
-  if (inViewport && !m_wasInViewport) {
-    // Only reset the timer when we transition from not visible to
-    // visible, because resetting the timer isn't cheap.
-    m_viewportTimer.startOneShot(kViewportTimerPollDelay, BLINK_FROM_HERE);
-  }
-  m_wasInViewport = inViewport;
-}
-
-void AutoplayExperimentHelper::updatePositionNotificationRegistration() {
-  if (m_registeredWithLayoutObject)
-    m_client->setRequestPositionUpdates(true);
-}
-
-void AutoplayExperimentHelper::triggerAutoplayViewportCheckForTesting() {
-  // Make sure that the last update appears to be sufficiently far in the
-  // past to appear that scrolling has stopped by now in viewportTimerFired.
-  m_lastLocationUpdateTime =
-      monotonicallyIncreasingTime() - kViewportTimerPollDelay - 1;
-  viewportTimerFired(nullptr);
-}
-
-void AutoplayExperimentHelper::viewportTimerFired(TimerBase*) {
-  double now = monotonicallyIncreasingTime();
-  double delta = now - m_lastLocationUpdateTime;
-  if (delta < kViewportTimerPollDelay) {
-    // If we are not visible, then skip the timer.  It will be started
-    // again if we become visible again.
-    if (m_wasInViewport)
-      m_viewportTimer.startOneShot(kViewportTimerPollDelay - delta,
-                                   BLINK_FROM_HERE);
-
-    return;
-  }
-
-  // Sufficient time has passed since the last scroll that we'll
-  // treat it as the end of scroll.  Autoplay if we should.
-  maybeStartPlaying();
-}
-
-bool AutoplayExperimentHelper::meetsVisibilityRequirements() const {
-  if (enabled(IfPageVisible) &&
-      client().pageVisibilityState() != PageVisibilityStateVisible)
-    return false;
-
-  if (!requiresViewportVisibility())
-    return true;
-
-  if (m_lastVisibleRect.isEmpty())
-    return false;
-
-  IntRect currentLocation = client().absoluteBoundingBoxRect();
-  if (currentLocation.isEmpty())
-    return false;
-
-  // In partial-viewport mode, we require only 1x1 area.
-  if (enabled(IfPartialViewport)) {
-    return m_lastVisibleRect.intersects(currentLocation);
-  }
-
-  // Element must be completely visible, or as much as fits.
-  // If element completely fills the screen, then truncate it to exactly
-  // match the screen.  Any element that is wider just has to cover.
-  if (currentLocation.x() <= m_lastVisibleRect.x() &&
-      currentLocation.x() + currentLocation.width() >=
-          m_lastVisibleRect.x() + m_lastVisibleRect.width()) {
-    currentLocation.setX(m_lastVisibleRect.x());
-    currentLocation.setWidth(m_lastVisibleRect.width());
-  }
-
-  if (currentLocation.y() <= m_lastVisibleRect.y() &&
-      currentLocation.y() + currentLocation.height() >=
-          m_lastVisibleRect.y() + m_lastVisibleRect.height()) {
-    currentLocation.setY(m_lastVisibleRect.y());
-    currentLocation.setHeight(m_lastVisibleRect.height());
-  }
-
-  return m_lastVisibleRect.contains(currentLocation);
-}
-
-bool AutoplayExperimentHelper::maybeStartPlaying() {
-  // See if we're allowed to autoplay now.
-  if (!isGestureRequirementOverridden())
-    return false;
-
-  // Start playing!
-  prepareToAutoplay(client().shouldAutoplay()
-                        ? GesturelessPlaybackStartedByAutoplayFlagAfterScroll
-                        : GesturelessPlaybackStartedByPlayMethodAfterScroll);
-
-  // Record that this played without a user gesture.
-  // This should rarely actually do anything.  Usually, playMethodCalled()
-  // and becameReadyToPlay will handle it, but toggling muted state can,
-  // in some cases, also trigger autoplay if the autoplay attribute is set
-  // after the media is ready to play.
-  autoplayMediaEncountered();
-
-  client().playInternal();
-
-  return true;
-}
-
-bool AutoplayExperimentHelper::isGestureRequirementOverridden() const {
-  return isEligible() && meetsVisibilityRequirements();
-}
-
-bool AutoplayExperimentHelper::isPlaybackDeferred() const {
-  return m_playPending;
-}
-
-bool AutoplayExperimentHelper::isEligible(EligibilityMode mode) const {
-  if (m_mode == Mode::ExperimentOff)
-    return false;
-
-  // If autoplay is disabled, no one is eligible.
-  if (!client().isAutoplayAllowedPerSettings())
-    return false;
-
-  // If no user gesture is required, then the experiment doesn't apply.
-  // This is what prevents us from starting playback more than once.
-  // Since this flag is never set to true once it's cleared, it will block
-  // the autoplay experiment forever.
-  if (!isLockedPendingUserGesture())
-    return false;
-
-  // Make sure that this is an element of the right type.
-  if (!enabled(ForVideo) && client().isHTMLVideoElement())
-    return false;
-
-  if (!enabled(ForAudio) && client().isHTMLAudioElement())
-    return false;
-
-  // If nobody has requested playback, either by the autoplay attribute or
-  // a play() call, then do nothing.
-
-  if (mode != IgnorePendingPlayback && !m_playPending &&
-      !client().shouldAutoplay())
-    return false;
-
-  // Note that the viewport test always returns false on desktop, which is
-  // why video-autoplay-experiment.html doesn't check -ifmobile .
-  if (enabled(IfMobile) && !client().isLegacyViewportType())
-    return false;
-
-  // If we require same-origin, then check the origin.
-  if (enabled(IfSameOrigin) && client().isCrossOrigin()) {
-    // We're cross-origin, so block unless it's muted content and OrMuted
-    // is enabled.  For good measure, we also block all audio elements.
-    if (client().isHTMLAudioElement() || !client().muted() ||
-        !enabled(OrMuted)) {
-      return false;
-    }
-  }
-
-  // If we require muted media and this is muted, then it is eligible.
-  if (enabled(IfMuted))
-    return client().muted();
-
-  // Element is eligible for gesture override, maybe muted.
-  return true;
-}
-
-void AutoplayExperimentHelper::muteIfNeeded() {
-  if (enabled(PlayMuted))
-    client().setMuted(true);
-}
-
-void AutoplayExperimentHelper::unlockUserGesture(AutoplayMetrics metric) {
-  // Note that this could be moved back into HTMLMediaElement fairly easily.
-  // It's only here so that we can record the reason, and we can hide the
-  // ordering between unlocking and recording from the element this way.
-  if (!client().isLockedPendingUserGesture())
-    return;
-
-  setDeferredOverrideReason(metric);
-  client().unlockUserGesture();
-}
-
-void AutoplayExperimentHelper::setDeferredOverrideReason(
-    AutoplayMetrics metric) {
-  // If the player is unlocked, then we don't care about any later reason.
-  if (!client().isLockedPendingUserGesture())
-    return;
-
-  m_autoplayDeferredMetric = metric;
-}
-
-void AutoplayExperimentHelper::prepareToAutoplay(AutoplayMetrics metric) {
-  // This also causes !isEligible, so that we don't allow autoplay more than
-  // once.  Be sure to do this before muteIfNeeded().
-  // Also note that, at this point, we know that we're goint to start
-  // playback.  However, we still don't record the metric here.  Instead,
-  // we let playbackStarted() do that later.
-  setDeferredOverrideReason(metric);
-
-  // Don't bother to call autoplayMediaEncountered, since whoever initiates
-  // playback has do it anyway, in case we don't allow autoplay.
-
-  unregisterForPositionUpdatesIfNeeded();
-  muteIfNeeded();
-
-  // Do not actually start playback here.
-}
-
-AutoplayExperimentHelper::Mode AutoplayExperimentHelper::fromString(
-    const String& mode) {
-  Mode value = ExperimentOff;
-  if (mode.contains("-forvideo"))
-    value |= ForVideo;
-  if (mode.contains("-foraudio"))
-    value |= ForAudio;
-  if (mode.contains("-ifpagevisible"))
-    value |= IfPageVisible;
-  if (mode.contains("-ifviewport"))
-    value |= IfViewport;
-  if (mode.contains("-ifpartialviewport"))
-    value |= IfPartialViewport;
-  if (mode.contains("-ifmuted"))
-    value |= IfMuted;
-  if (mode.contains("-ifmobile"))
-    value |= IfMobile;
-  if (mode.contains("-ifsameorigin"))
-    value |= IfSameOrigin;
-  if (mode.contains("-ormuted"))
-    value |= OrMuted;
-  if (mode.contains("-playmuted"))
-    value |= PlayMuted;
-
-  return value;
-}
-
-void AutoplayExperimentHelper::autoplayMediaEncountered() {
-  if (!m_autoplayMediaEncountered) {
-    m_autoplayMediaEncountered = true;
-    recordAutoplayMetric(AutoplayMediaFound);
-  }
-}
-
-bool AutoplayExperimentHelper::isLockedPendingUserGesture() const {
-  return client().isLockedPendingUserGesture();
-}
-
-void AutoplayExperimentHelper::playbackStarted() {
-  recordAutoplayMetric(AnyPlaybackStarted);
-
-  // Forget about our most recent visibility check.  If another override is
-  // requested, then we'll have to refresh it.  That way, we don't need to
-  // keep it up to date in the interim.
-  m_lastVisibleRect = IntRect();
-  m_wasInViewport = false;
-
-  // Any pending play is now playing.
-  m_playPending = false;
-
-  if (m_playbackStartedMetricRecorded)
-    return;
-
-  // Whether we record anything or not, we only want to record metrics for
-  // the initial playback.
-  m_playbackStartedMetricRecorded = true;
-
-  // If this is a gestureless start, then record why it was allowed.
-  if (m_autoplayMediaEncountered) {
-    m_waitingForAutoplayPlaybackStop = true;
-    recordAutoplayMetric(m_autoplayDeferredMetric);
-  }
-}
-
-void AutoplayExperimentHelper::playbackStopped() {
-  const bool ended = client().ended();
-  const bool bailout = isBailout();
-
-  // Record that play was paused.  We don't care if it was autoplay,
-  // play(), or the user manually started it.
-  recordAutoplayMetric(ended ? AnyPlaybackComplete : AnyPlaybackPaused);
-  if (bailout)
-    recordAutoplayMetric(AnyPlaybackBailout);
-
-  // If this was a gestureless play, then record that separately.
-  // These cover attr and play() gestureless starts.
-  if (m_waitingForAutoplayPlaybackStop) {
-    m_waitingForAutoplayPlaybackStop = false;
-
-    recordAutoplayMetric(ended ? AutoplayComplete : AutoplayPaused);
-
-    if (bailout)
-      recordAutoplayMetric(AutoplayBailout);
-  }
-}
-
-void AutoplayExperimentHelper::recordAutoplayMetric(AutoplayMetrics metric) {
-  client().recordAutoplayMetric(metric);
-}
-
-bool AutoplayExperimentHelper::isBailout() const {
-  // We count the user as having bailed-out on the video if they watched
-  // less than one minute and less than 50% of it.
-  const double playedTime = client().currentTime();
-  const double progress = playedTime / client().duration();
-  return (playedTime < 60) && (progress < 0.5);
-}
-
-void AutoplayExperimentHelper::recordSandboxFailure() {
-  // We record autoplayMediaEncountered here because we know
-  // that the autoplay attempt will fail.
-  autoplayMediaEncountered();
-  recordAutoplayMetric(AutoplayDisabledBySandbox);
-}
-
-void AutoplayExperimentHelper::loadingStarted() {
-  if (m_recordedElement)
-    return;
-
-  m_recordedElement = true;
-  recordAutoplayMetric(client().isHTMLVideoElement() ? AnyVideoElement
-                                                     : AnyAudioElement);
-}
-
-bool AutoplayExperimentHelper::requiresViewportVisibility() const {
-  return client().isHTMLVideoElement() &&
-         (enabled(IfViewport) || enabled(IfPartialViewport));
-}
-
-bool AutoplayExperimentHelper::isExperimentEnabled() {
-  return m_mode != Mode::ExperimentOff;
-}
-
-}  // namespace blink