[Oilpan] Create UnsafePtr to store on-heap pointers in Vector

third_party/WebKit/Source/platform/heap/Heap.h

Index: third_party/WebKit/Source/platform/heap/Heap.h
diff --git a/third_party/WebKit/Source/platform/heap/Heap.h b/third_party/WebKit/Source/platform/heap/Heap.h
index 5d45a3d7e14e5cc7405d7d319712debfcfdef783..355b1719b087a41de758b9d4e15e43f71888ce69 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.h
+++ b/third_party/WebKit/Source/platform/heap/Heap.h
@@ -43,6 +43,10 @@
 
 namespace blink {
 
+template<typename T> class Member;
+template<typename T> class WeakMember;
+template<typename T> class UntracedMember;
+
 template<typename T, bool = NeedsAdjustAndMark<T>::value> class ObjectAliveTrait;
 
 template<typename T>
@@ -100,6 +104,11 @@ public:
         return isHeapObjectAlive(member.get());
     }
     template<typename T>
+    static inline bool isHeapObjectAlive(const UntracedMember<T>& member)
+    {
+        return isHeapObjectAlive(member.get());
+    }
+    template<typename T>
     static inline bool isHeapObjectAlive(const RawPtr<T>& ptr)
     {
         return isHeapObjectAlive(ptr.get());