Oilpan: HeapVectorBacking should call destructors for its elements

Source/wtf/Vector.h

Index: Source/wtf/Vector.h
diff --git a/Source/wtf/Vector.h b/Source/wtf/Vector.h
index f353c01cd4140420a5b574bca4c90a2ba1aaa8f1..c30cad423fb7673e6863d0197b63b821f8eebf8c 100644
--- a/Source/wtf/Vector.h
+++ b/Source/wtf/Vector.h
@@ -1026,6 +1026,7 @@ static const size_t kInitialVectorSize = WTF_VECTOR_INITIAL_SIZE;
         Base::allocateExpandedBuffer(newCapacity);
         ANNOTATE_NEW_BUFFER(begin(), capacity(), m_size);
         TypeOperations::move(oldBuffer, oldEnd, begin());
+        clearUnusedSlots(oldBuffer, oldEnd);
         ANNOTATE_DELETE_BUFFER(oldBuffer, oldCapacity, m_size);
         Base::deallocateBuffer(oldBuffer);
     }
@@ -1066,6 +1067,7 @@ static const size_t kInitialVectorSize = WTF_VECTOR_INITIAL_SIZE;
             if (begin() != oldBuffer) {
                 ANNOTATE_NEW_BUFFER(begin(), capacity(), m_size);
                 TypeOperations::move(oldBuffer, oldEnd, begin());
+                clearUnusedSlots(oldBuffer, oldEnd);
                 ANNOTATE_DELETE_BUFFER(oldBuffer, oldCapacity, m_size);
             }
         } else {