Web Animations: Avoid iteration when checking for outdated animations on timeline

Source/core/animation/Animation.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 349 matching lines @@
         ASSERT(m_held);
 
         if (m_playbackRate == 0) {
             setStartTimeInternal(timelineTime);
         } else {
             setStartTimeInternal(timelineTime + currentTimeInternal() / -m_playbackRate);
         }
 
         // FIXME: This avoids marking this animation as outdated needlessly when a start time
         // is notified, but we should refactor how outdating works to avoid this.
-        m_outdated = false;
-
+        clearOutdated();
         m_currentTimePending = false;
     }
 }
 
 bool Animation::affects(const Element& element, CSSPropertyID property) const
 {
     if (!m_content || !m_content->isAnimation())
         return false;
 
     const KeyframeEffect* effect = toKeyframeEffect(m_content.get());
@@ skipping 294 matching lines @@
 
     double storedCurrentTime = currentTimeInternal();
     if ((m_playbackRate < 0 && playbackRate >= 0) || (m_playbackRate > 0 && playbackRate <= 0))
         m_finished = false;
 
     m_playbackRate = playbackRate;
     m_startTime = std::numeric_limits<double>::quiet_NaN();
     setCurrentTimeInternal(storedCurrentTime, TimingUpdateOnDemand);
 }
 
+void Animation::clearOutdated()
+{
+    if (!m_outdated)
+        return;
+    m_outdated = false;
+    if (m_timeline)
+        m_timeline->clearOutdatedAnimation(this);
+}
+
 void Animation::setOutdated()
 {
+    if (m_outdated)
+        return;
     m_outdated = true;
     if (m_timeline)
         m_timeline->setOutdatedAnimation(this);
 }
 
 bool Animation::canStartAnimationOnCompositor() const
 {
     // FIXME: Timeline playback rates should be compositable
     if (m_playbackRate == 0 || (std::isinf(sourceEnd()) && m_playbackRate < 0) || (timeline() && timeline()->playbackRate() != 1))
         return false;
@@ skipping 82 matching lines @@
     return toKeyframeEffect(m_content.get())->hasActiveAnimationsOnCompositor();
 }
 
 bool Animation::update(TimingUpdateReason reason)
 {
     if (!m_timeline)
         return false;
 
     PlayStateUpdateScope updateScope(*this, reason, DoNotSetCompositorPending);
 
-    m_outdated = false;
+    clearOutdated();
     bool idle = playStateInternal() == Idle;
 
     if (m_content) {
         double inheritedTime = idle || isNull(m_timeline->currentTimeInternal())
             ? nullValue()
             : currentTimeInternal();
 
         if (!isNull(inheritedTime)) {
             double timeForClipping = m_held && (!limited(inheritedTime) || isNull(m_startTime))
                 // Use hold time when there is no start time.
@@ skipping 277 matching lines @@
     visitor->trace(m_content);
     visitor->trace(m_timeline);
     visitor->trace(m_pendingFinishedEvent);
     visitor->trace(m_finishedPromise);
     visitor->trace(m_readyPromise);
     EventTargetWithInlineData::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace