Use-count when SMIL animation renders a frame

third_party/WebKit/Source/core/svg/animation/SMILTimeContainer.cpp

 /*
  * Copyright (C) 2008 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 12 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "core/svg/animation/SMILTimeContainer.h"
 
 #include "core/animation/AnimationClock.h"
 #include "core/animation/AnimationTimeline.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
+#include "core/frame/UseCounter.h"
 #include "core/svg/SVGSVGElement.h"
 #include "core/svg/animation/SVGSMILElement.h"
 #include <algorithm>
 
 namespace blink {
 
 static const double initialFrameDelay = 0.025;
 static const double animationPolicyOnceDuration = 3.000;
 
 SMILTimeContainer::SMILTimeContainer(SVGSVGElement& owner)
     : m_beginTime(0)
     , m_pauseTime(0)
     , m_resumeTime(0)
     , m_accumulatedActiveTime(0)
     , m_presetStartTime(0)
     , m_frameSchedulingState(Idle)
     , m_documentOrderIndexesDirty(false)
+    , m_hasUpdatedAnimation(false)
     , m_wakeupTimer(this, &SMILTimeContainer::wakeupTimerFired)
     , m_animationPolicyOnceTimer(this, &SMILTimeContainer::animationPolicyTimerFired)
     , m_ownerSVGElement(&owner)
 #if ENABLE(ASSERT)
     , m_preventScheduledAnimationsChanges(false)
 #endif
 {
 }
 
 SMILTimeContainer::~SMILTimeContainer()
@@ skipping 445 matching lines @@
     std::sort(animationsToApply.begin(), animationsToApply.end(), PriorityCompare(elapsed));
 
     unsigned animationsToApplySize = animationsToApply.size();
     if (!animationsToApplySize) {
 #if ENABLE(ASSERT)
         m_preventScheduledAnimationsChanges = false;
 #endif
         return earliestFireTime;
     }
 
+    if (!m_hasUpdatedAnimation) {
+        m_hasUpdatedAnimation = true;
+        UseCounter::count(&document(), UseCounter::SVGSMILAnimationAppliedEffect);

[fs, 2016/07/21 10:17:33]

You could ditch the m_hasUpdatedAnimation - once the "counter" (flag) is set, it
is set. I don't think the additional overhead is something worth caring about
(unless prompted.)

[suzyh_UTC10 (ex-contributor), 2016/07/25 03:16:00]

Done.

+    }
+
     // Apply results to target elements.
     for (unsigned i = 0; i < animationsToApplySize; ++i)
         animationsToApply[i]->applyResultsToTarget();
 
 #if ENABLE(ASSERT)
     m_preventScheduledAnimationsChanges = false;
 #endif
 
     for (unsigned i = 0; i < animationsToApplySize; ++i) {
         if (animationsToApply[i]->isConnected() && animationsToApply[i]->isSVGDiscardElement()) {
@@ skipping 18 matching lines @@
     setElapsed(elapsed().value() + initialFrameDelay);
 }
 
 DEFINE_TRACE(SMILTimeContainer)
 {
     visitor->trace(m_scheduledAnimations);
     visitor->trace(m_ownerSVGElement);
 }
 
 } // namespace blink