Convert m_deferredLoadTimer to Unthrottled frame-specific timer and include in didMoveToNewDocument.

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

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights
  * reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 410 matching lines @@
       m_readyStateMaximum(kHaveNothing),
       m_volume(1.0f),
       m_lastSeekTime(0),
       m_previousProgressTime(std::numeric_limits<double>::max()),
       m_duration(std::numeric_limits<double>::quiet_NaN()),
       m_lastTimeUpdateEventWallTime(0),
       m_lastTimeUpdateEventMediaTime(std::numeric_limits<double>::quiet_NaN()),
       m_defaultPlaybackStartPosition(0),
       m_loadState(WaitingForSource),
       m_deferredLoadState(NotDeferred),
-      m_deferredLoadTimer(this, &HTMLMediaElement::deferredLoadTimerFired),
+      m_deferredLoadTimer(
+          TaskRunnerHelper::get(TaskType::Unthrottled, &document),
+          this,
+          &HTMLMediaElement::deferredLoadTimerFired),
       m_webLayer(nullptr),
       m_displayMode(Unknown),
       m_officialPlaybackPosition(0),
       m_officialPlaybackPositionNeedsUpdate(true),
       m_fragmentEndTime(std::numeric_limits<double>::quiet_NaN()),
       m_pendingActionFlags(0),
       m_lockedPendingUserGesture(false),
       m_lockedPendingUserGestureIfCrossOriginExperimentEnabled(true),
       m_playing(false),
       m_shouldDelayLoadEvent(false),
@@ skipping 57 matching lines @@
   // doesn't get dispatched during the object destruction.
   // See Document::isDelayingLoadEvent().
   // Also see http://crbug.com/275223 for more details.
   clearMediaPlayerAndAudioSourceProviderClientWithoutLocking();
 }
 
 void HTMLMediaElement::didMoveToNewDocument(Document& oldDocument) {
   BLINK_MEDIA_LOG << "didMoveToNewDocument(" << (void*)this << ")";
 
   m_loadTimer.moveToNewTaskRunner(
-      TaskRunnerHelper::get(TaskType::Unthrottled, &document()));
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));
   m_progressEventTimer.moveToNewTaskRunner(
-      TaskRunnerHelper::get(TaskType::Unthrottled, &document()));
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));
   m_playbackProgressTimer.moveToNewTaskRunner(
-      TaskRunnerHelper::get(TaskType::Unthrottled, &document()));
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));
   m_audioTracksTimer.moveToNewTaskRunner(
-      TaskRunnerHelper::get(TaskType::Unthrottled, &document()));
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));
   m_viewportFillDebouncerTimer.moveToNewTaskRunner(
-      TaskRunnerHelper::get(TaskType::Unthrottled, &document()));
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));
   m_checkViewportIntersectionTimer.moveToNewTaskRunner(
-      TaskRunnerHelper::get(TaskType::Unthrottled, &document()));
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));

[haraken, 2017/02/27 07:50:45]

Is this your intentional change? You're changing existing Unthrottled timers to
MediaElementEvent timers.

[foolip, 2017/02/27 15:39:08]

Most of these changes are probably correct, but some probably refer to bits that
don't correspond to a "queue a task" in the spec. Joel, can you go through the
call sites to see which aren't obviously spec algorithms of the sort quoted
below, and say something about those cases?

+  m_deferredLoadTimer.moveToNewTaskRunner(
+      TaskRunnerHelper::get(TaskType::MediaElementEvent, &document()));

[foolip, 2017/02/27 15:39:08]

At the m_deferredLoadTimer.startOneShot call site we are inside
HTMLMediaElement::deferLoad() which implements a spec algorithm
https://html.spec.whatwg.org/multipage/embedded-content.html#concept-media-lo...
which should use the "media element event task source" because "Except where
otherwise explicitly specified, the task source for all the tasks queued in this
section and its subsections is the media element event task source of the media
element in question."

So, this bit is correct.

 
   m_autoplayUmaHelper->didMoveToNewDocument(oldDocument);
   // If any experiment is enabled, then we want to enable a user gesture by
   // default, otherwise the experiment does nothing.
   bool oldDocumentRequiresUserGesture =
       computeLockedPendingUserGesture(oldDocument);
   bool newDocumentRequiresUserGesture =
       computeLockedPendingUserGesture(document());
   if (newDocumentRequiresUserGesture && !oldDocumentRequiresUserGesture)
     m_lockedPendingUserGesture = true;
@@ skipping 3639 matching lines @@
       kMostlyFillViewportBecomeStableSeconds, BLINK_FROM_HERE);
 }
 
 void HTMLMediaElement::viewportFillDebouncerTimerFired(TimerBase*) {
   m_mostlyFillingViewport = true;
   if (m_webMediaPlayer)
     m_webMediaPlayer->becameDominantVisibleContent(m_mostlyFillingViewport);
 }
 
 }  // namespace blink