Oilpan: Remove a visitor parameter from isHeapObjectAlive

Source/wtf/Vector.h

Index: Source/wtf/Vector.h
diff --git a/Source/wtf/Vector.h b/Source/wtf/Vector.h
index ddf52d0da1139667546eb8401487778466d0ae9a..0c7e0adb37b668df4b602243618d95408ea8c97f 100644
--- a/Source/wtf/Vector.h
+++ b/Source/wtf/Vector.h
@@ -1321,7 +1321,7 @@ static const size_t kInitialVectorSize = WTF_VECTOR_INITIAL_SIZE;
             // the conservative scanning traced an on-stack (false-positive
             // or real) pointer to the HeapVector, and then visitor->trace()
             // traces the HeapVector.
-            if (visitor->isHeapObjectAlive(buffer()))
+            if (Allocator::isHeapObjectAlive(buffer()))
                 return;
             Allocator::markNoTracing(visitor, buffer());
         }