Oilpan: Remove a visitor parameter from isHeapObjectAlive

Source/wtf/Vector.h

 /*
  *  Copyright (C) 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 1303 matching lines @@
     {
         ASSERT(Allocator::isGarbageCollected); // Garbage collector must be enabled.
         if (!buffer())
             return;
         if (this->hasOutOfLineBuffer()) {
             // This is a performance optimization for a case where the buffer
             // has been already traced by somewhere. This can happen if
             // 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());
         }
         const T* bufferBegin = buffer();
         const T* bufferEnd = buffer() + size();
         if (ShouldBeTraced<VectorTraits<T>>::value) {
             for (const T* bufferEntry = bufferBegin; bufferEntry != bufferEnd; bufferEntry++)
                 Allocator::template trace<VisitorDispatcher, T, VectorTraits<T>>(visitor, *const_cast<T*>(bufferEntry));
             checkUnusedSlots(buffer() + size(), buffer() + capacity());
         }
     }
 
 #if !ENABLE(OILPAN)
     template<typename T, size_t N>
     struct NeedsTracing<Vector<T, N>> {
         static const bool value = false;
     };
 #endif
 
 } // namespace WTF
 
 using WTF::Vector;
 
 #endif // WTF_Vector_h