Oilpan: add transition types to track interface objects.

Source/platform/heap/Handle.h

Index: Source/platform/heap/Handle.h
diff --git a/Source/platform/heap/Handle.h b/Source/platform/heap/Handle.h
index a1517894c269b3527aeb10bb93cc85e8a1508d2a..5735f08d1198708525c195d952f14558aa933d6a 100644
--- a/Source/platform/heap/Handle.h
+++ b/Source/platform/heap/Handle.h
@@ -739,6 +739,7 @@ template<typename T, typename U> inline bool operator!=(const Persistent<T>& a,
 #define RefPtrWillBeMember WebCore::Member
 #define RefPtrWillBeCrossThreadPersistent WebCore::CrossThreadPersistent
 #define RawPtrWillBeMember WebCore::Member
+#define RawPtrWillBePersistent WebCore::Persistent

[haraken, 2014/04/21 01:30:54]

Oh, this macro seems dangerous :) I agree that we need this in some situation
but we should be very careful that it won't produce memory leaks.

[sof, 2014/04/21 15:23:42]

If we don't want to add it for that reason, the alternative is to keep a bare
pointer on VTTCueBox. Ownership and lifetime of it should already be such (I
hope!) in the non-Oilpan case that the cue cannot disappear before the cue box. 

But I considered it cleaner to explicitly keep a persistent reference, hence its
addition here.

[haraken, 2014/04/22 02:37:47]

Agreed. Memory leak would be better than crash.

We just need to be careful that we don't introduce memory leaks when introducing
RawPtrWillBePersistent.

 #define RawPtrWillBeWeakMember WebCore::WeakMember
 #define OwnPtrWillBeMember WebCore::Member
 #define OwnPtrWillBePersistent WebCore::Persistent
@@ -815,6 +816,7 @@ public:
 #define RefPtrWillBeMember WTF::RefPtr
 #define RefPtrWillBeCrossThreadPersistent WTF::RefPtr
 #define RawPtrWillBeMember WTF::RawPtr
+#define RawPtrWillBePersistent WTF::RawPtr
 #define RawPtrWillBeWeakMember WTF::RawPtr
 #define OwnPtrWillBeMember WTF::OwnPtr
 #define OwnPtrWillBePersistent WTF::OwnPtr