Oilpan: move node/element rare data objects to the heap.

Source/core/animation/ActiveAnimations.h

Index: Source/core/animation/ActiveAnimations.h
diff --git a/Source/core/animation/ActiveAnimations.h b/Source/core/animation/ActiveAnimations.h
index 1a4c0a0bb119a4b2f93e11c8cf203ba90549652f..5f16f8a1d481c583dad754b705e0cd2fdf8e41f6 100644
--- a/Source/core/animation/ActiveAnimations.h
+++ b/Source/core/animation/ActiveAnimations.h
@@ -53,7 +53,6 @@ public:
     }
 
     ~ActiveAnimations();
-    void dispose();
 
     // Animations that are currently active for this element, their effects will be applied
     // during a style recalc. CSS Transitions are included in this stack.
@@ -94,6 +93,14 @@ private:
     // won't be needed once Element and Animation are moved to Oilpan.
     Vector<Animation*> m_animations;
 
+#if ENABLE(OILPAN)
+    // Keep a back reference to the target Element, so that we know
+    // that when this object is finalized, the Element will be dead
+    // too (=> disposing of the above Animations can be done
+    // correctly from our finalizer.)
+    Member<Element> m_target;

[haraken, 2014/05/04 01:46:24]

I don't fully understand why we need to add m_target here. Instead, probably
should we change Animation::m_target from a raw pointer to a Member?

[sof, 2014/05/04 18:59:22]

With it, you'll be able to accurately notify the Animations that the Element has
been destroyed in ~ActiveAnimations.

I didn't want to make more changes to animations/ than needed, given that its
Oilpan changes hasn't settled yet (and object relationships appear non-trivial
:) )

+#endif
+
     // CSSAnimations checks if a style change is due to animation.
     friend class CSSAnimations;
 };