Oilpan: Move AnimatableValue's hierarchy to oilpan's heap

Source/core/animation/css/CSSAnimations.h

Index: Source/core/animation/css/CSSAnimations.h
diff --git a/Source/core/animation/css/CSSAnimations.h b/Source/core/animation/css/CSSAnimations.h
index e730fc11a58179663f6765d0d5787533ba33040b..0f48eae048adb160110a2828cafcaadc44ccddb4 100644
--- a/Source/core/animation/css/CSSAnimations.h
+++ b/Source/core/animation/css/CSSAnimations.h
@@ -78,8 +78,8 @@ public:
     {
         NewTransition newTransition;
         newTransition.id = id;
-        newTransition.from = from;
-        newTransition.to = to;
+        newTransition.from = const_cast<AnimatableValue*>(from);
+        newTransition.to = const_cast<AnimatableValue*>(to);
         newTransition.animation = animation;
         m_newTransitions.set(id, newTransition);
     }
@@ -96,12 +96,20 @@ public:
     const Vector<AtomicString>& animationsWithPauseToggled() const { return m_animationsWithPauseToggled; }
 
     struct NewTransition {
+        ALLOW_ONLY_INLINE_ALLOCATION();
+    public:
+        void trace(Visitor* visitor)
+        {
+            visitor->trace(from);
+            visitor->trace(to);
+        }
+
         CSSPropertyID id;
-        const AnimatableValue* from;
-        const AnimatableValue* to;
+        RawPtrWillBeMember<AnimatableValue> from;
+        RawPtrWillBeMember<AnimatableValue> to;
         RefPtr<InertAnimation> animation;
     };
-    typedef HashMap<CSSPropertyID, NewTransition> NewTransitionMap;
+    typedef WillBeHeapHashMap<CSSPropertyID, NewTransition> NewTransitionMap;
     const NewTransitionMap& newTransitions() const { return m_newTransitions; }
     const HashSet<CSSPropertyID>& cancelledTransitions() const { return m_cancelledTransitions; }
 
@@ -164,11 +172,19 @@ private:
     // ParGroup to drive multiple animations from a single AnimationPlayer.
     typedef HashMap<AtomicString, HashSet<RefPtr<AnimationPlayer> > > AnimationMap;
     struct RunningTransition {
+        ALLOW_ONLY_INLINE_ALLOCATION();
+    public:
+        void trace(Visitor* visitor)
+        {
+            visitor->trace(from);
+            visitor->trace(to);
+        }
+
         Animation* transition; // The TransitionTimeline keeps the AnimationPlayers alive
-        const AnimatableValue* from;
-        const AnimatableValue* to;
+        RawPtrWillBeMember<AnimatableValue> from;
+        RawPtrWillBeMember<AnimatableValue> to;
     };
-    typedef HashMap<CSSPropertyID, RunningTransition > TransitionMap;
+    typedef WillBeHeapHashMap<CSSPropertyID, RunningTransition> TransitionMap;
     AnimationMap m_animations;
     TransitionMap m_transitions;
     OwnPtr<CSSAnimationUpdate> m_pendingUpdate;