Make ScriptWrappable's destructor empty in oilpan bulids

Source/bindings/core/v8/ScriptWrappable.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 190 matching lines @@
         RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(value == 0
             || value->GetAlignedPointerFromInternalField(v8DOMWrapperObjectIndex) == V8T::toInternalPointer(objectAsT));
     }
 
     inline bool containsWrapper() const { return (m_wrapperOrTypeInfo & 1); }
     inline bool containsTypeInfo() const { return m_wrapperOrTypeInfo && !(m_wrapperOrTypeInfo & 1); }
 
 protected:
     ~ScriptWrappable()
     {
+        // In Oilpan we don't need to call the destructor.
+        //
+        // - 'RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!containsWrapper())' is not needed
+        // because Oilpan is not using reference counting at all. If containsWrapper() is true,
+        // it means that ScriptWrappable still has a wrapper. In this case, the destructor
+        // must not be called since the wrapper has a persistent handle back to this ScriptWrappable object.
+        // Assuming that Oilpan's GC is correct (If we cannot assume this, a lot of more things are
+        // already broken), we must not hit the RELEASE_ASSERT.
+        //
+        // - 'm_wrapperOrTypeInfo = 0' is not needed because Oilpan's GC zeros out memory when
+        // the memory is collected and added to a free list.
+#if !ENABLE(OILPAN)
         // We must not get deleted as long as we contain a wrapper. If this happens, we screwed up ref
         // counting somewhere. Crash here instead of crashing during a later gc cycle.
         RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!containsWrapper());
         ASSERT(m_wrapperOrTypeInfo); // Assert initialization via init() even if not subsequently wrapped.
         m_wrapperOrTypeInfo = 0; // Break UAF attempts to wrap.
+#endif
     }
 
 private:
     void getPersistent(v8::Persistent<v8::Object>* persistent) const
     {
         ASSERT(persistent);
 
         // Horrible and super unsafe: Cast the Persistent to an Object*, so
         // that we can inject the wrapped value. This only works because
         // we previously 'stole' the object pointer from a Persistent in
@@ skipping 34 matching lines @@
         // FIXME: I noticed that 50%~ of minor GC cycle times can be consumed
         // inside data.GetParameter()->deref(), which causes Node destructions. We should
         // make Node destructions incremental.
         releaseObject(data.GetValue());
     }
 };
 
 } // namespace WebCore
 
 #endif // ScriptWrappable_h