Discard SampledEffects on elements if they are redundant

third_party/WebKit/Source/core/animation/AnimationStack.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 83 matching lines @@
 }
 
 ActiveInterpolationsMap AnimationStack::activeInterpolations(AnimationStack* animationStack, const HeapVector<Member<const InertEffect>>* newAnimations, const HeapHashSet<Member<const Animation>>* suppressedAnimations, KeyframeEffect::Priority priority, PropertyHandleFilter propertyHandleFilter)
 {
     ActiveInterpolationsMap result;
 
     if (animationStack) {
         HeapVector<Member<SampledEffect>>& sampledEffects = animationStack->m_sampledEffects;
         // std::sort doesn't work with OwnPtrs
         nonCopyingSort(sampledEffects.begin(), sampledEffects.end(), compareSampledEffects);
-        animationStack->removeClearedSampledEffects();
+        animationStack->removeRedundantSampledEffects();
         for (const auto& sampledEffect : sampledEffects) {
             if (sampledEffect->priority() != priority || (suppressedAnimations && sampledEffect->effect() && suppressedAnimations->contains(sampledEffect->effect()->animation())))
                 continue;
             copyToActiveInterpolationsMap(sampledEffect->interpolations(), propertyHandleFilter, result);
         }
     }
 
     if (newAnimations)
         copyNewAnimationsToActiveInterpolationsMap(*newAnimations, propertyHandleFilter, result);
 
     return result;
 }
 
-void AnimationStack::removeClearedSampledEffects()
+void AnimationStack::removeRedundantSampledEffects()
 {
-    size_t dest = 0;
+    HashSet<PropertyHandle> replacedProperties;
+    for (size_t i = m_sampledEffects.size(); i--;) {
+        SampledEffect& sampledEffect = *m_sampledEffects[i];
+        if (sampledEffect.willNeverChange()) {
+            sampledEffect.removeReplacedInterpolations(replacedProperties);
+            sampledEffect.updateReplacedProperties(replacedProperties);
+        }
+    }
+
+    size_t newSize = 0;
     for (auto& sampledEffect : m_sampledEffects) {
-        if (sampledEffect->effect())
-            m_sampledEffects[dest++].swap(sampledEffect);
+        if (!sampledEffect->interpolations().isEmpty())
+            m_sampledEffects[newSize++].swap(sampledEffect);
+        else if (sampledEffect->effect())
+            sampledEffect->effect()->notifySampledEffectRemovedFromAnimationStack();
     }
-    m_sampledEffects.shrink(dest);
+    m_sampledEffects.shrink(newSize);
 }
 
 DEFINE_TRACE(AnimationStack)
 {
     visitor->trace(m_sampledEffects);
 }
 
 bool AnimationStack::getAnimatedBoundingBox(FloatBox& box, CSSPropertyID property) const
 {
     FloatBox originalBox(box);
     for (const auto& sampledEffect : m_sampledEffects) {
         if (sampledEffect->effect() && sampledEffect->effect()->affects(PropertyHandle(property))) {
             KeyframeEffect* effect = sampledEffect->effect();
             const Timing& timing = effect->specifiedTiming();
             double startRange = 0;
             double endRange = 1;
             timing.timingFunction->range(&startRange, &endRange);
             FloatBox expandingBox(originalBox);
             if (!CompositorAnimations::instance()->getAnimatedBoundingBox(expandingBox, *effect->model(), startRange, endRange))
                 return false;
             box.expandTo(expandingBox);
         }
     }
     return true;
 }
 
 } // namespace blink