[Oilpan]: Move StyleKeyFrame to the oilpan heap using transition types.

Source/core/css/CSSKeyframeRule.cpp

 /*
  * Copyright (C) 2007, 2008, 2012 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 145 matching lines @@
         m_propertiesCSSOMWrapper = StyleRuleCSSStyleDeclaration::create(m_keyframe->mutableProperties(), const_cast<CSSKeyframeRule*>(this));
     return m_propertiesCSSOMWrapper.get();
 }
 
 void CSSKeyframeRule::reattach(StyleRuleBase*)
 {
     // No need to reattach, the underlying data is shareable on mutation.
     ASSERT_NOT_REACHED();
 }
 
+void CSSKeyframeRule::trace(Visitor* visitor)
+{
+    visitor->trace(m_keyframe);
+    CSSRule::trace(visitor);
+}
+
 } // namespace WebCore