Removed add/removeScopedStyleResolver from StyleEngine

Source/core/animation/css/CSSAnimations.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 181 matching lines @@
     }
     ASSERT(startKeyframe->properties().size() == allProperties.size());
     ASSERT(endKeyframe->properties().size() == allProperties.size());
 }
 
 } // namespace
 
 const StyleRuleKeyframes* CSSAnimations::matchScopedKeyframesRule(StyleResolver* resolver, const Element* element, const StringImpl* animationName)
 {
     // FIXME: This is all implementation detail of style resolver, CSSAnimations shouldn't be reaching into any of it.
-    if (element->document().styleEngine()->hasOnlyScopedResolverForDocument())
-        return element->document().scopedStyleResolver()->keyframeStylesForAnimation(animationName);
+    if (element->document().styleEngine()->onlyDocumentHasStyles()) {
+        if (ScopedStyleResolver* resolver = element->document().scopedStyleResolver())
+            return resolver->keyframeStylesForAnimation(animationName);
+        return nullptr;
+    }
 
     WillBeHeapVector<RawPtrWillBeMember<ScopedStyleResolver>, 8> stack;
     resolver->styleTreeResolveScopedKeyframesRules(element, stack);
     if (stack.isEmpty())

[kochi, 2014/11/26 07:28:37]

If the above onlyDocumentHasStyles() is not true, can this happen?

[tasak, 2014/11/26 08:46:32]

Suppose that we have some shadow trees. Some of the trees have style elements,
but others have no style elements.

Now we are invoking matchScopedKeyframesRule for an element in a shadow tree
which has no style elements.

In this case, the stack is empty, but styleEngine says onlyDocumentHasStyle() is
false.

[kochi, 2014/11/26 09:12:07]

Acknowledged.

         return nullptr;
 
     for (size_t i = 0; i < stack.size(); ++i) {
         if (const StyleRuleKeyframes* keyframesRule = stack.at(i)->keyframeStylesForAnimation(animationName))
             return keyframesRule;
     }
     return nullptr;
 }
 
 CSSAnimations::CSSAnimations()
@@ skipping 519 matching lines @@
 #if ENABLE(OILPAN)
     visitor->trace(m_newTransitions);
     visitor->trace(m_activeInterpolationsForAnimations);
     visitor->trace(m_activeInterpolationsForTransitions);
     visitor->trace(m_newAnimations);
     visitor->trace(m_cancelledAnimationPlayers);
 #endif
 }
 
 } // namespace blink