Web Animations: Introduce ActiveAnimations and AnimationStack

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 6f544242c4d57bf8edacbec294f2b9fa4197967a..6fdd05cfee50af0d931230665ca386563d81ba35 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -37,6 +37,7 @@
 #include "XMLNames.h"
 #include "core/animation/AnimatableValue.h"
 #include "core/animation/Animation.h"
+#include "core/animation/DocumentTimeline.h"
 #include "core/css/CSSCalculationValue.h"
 #include "core/css/CSSCursorImageValue.h"
 #include "core/css/CSSDefaultStyleSheets.h"
@@ -1054,13 +1055,14 @@ void StyleResolver::applyAnimatedProperties(const Element* target)
 {
     ASSERT(pass != VariableDefinitions);
     ASSERT(pass != AnimationProperties);
-    if (!target->hasActiveAnimations())
+    AnimationStack animationStack = target->document()->timeline()->animationStack();
+    if (!animationStack.hasActiveAnimations(target))

[esprehn, 2013/07/17 06:48:01]

This requires two hash lookups now for every element. Once for has() and again
for get() below.

[dstockwell, 2013/07/17 13:10:19]

I think we should still proceed with this for now. We're guarded by a runtime
flag and the AnimationStack API should give flexibility to change where/how this
data ends up being stored. There should be numerous ways we can improve on the
current situation if necessary.

Shane also has some other thoughts on how to slim down ElementRareData.

         return;
 
-    Vector<Animation*>* animations = target->activeAnimations();
+    const Vector<Animation*>& animations = animationStack.activeAnimations(target);
 
-    for (size_t i = 0; i < animations->size(); ++i) {
-        RefPtr<Animation> animation = animations->at(i);
+    for (size_t i = 0; i < animations.size(); ++i) {
+        RefPtr<Animation> animation = animations.at(i);
         const AnimationEffect::CompositableValueMap* compositableValues = animation->compositableValues();
         for (AnimationEffect::CompositableValueMap::const_iterator iter = compositableValues->begin(); iter != compositableValues->end(); ++iter) {
             CSSPropertyID property = iter->key;