Support ignorance of base class finalizers.

tools/clang/blink_gc_plugin/tests/class_requires_finalization_field.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CLASS_REQUIRES_FINALIZATION_H_
 #define CLASS_REQUIRES_FINALIZATION_H_
 
 #include "heap/stubs.h"
 
 namespace WebCore {
 
 class A : public GarbageCollected<A> {
 public:
     virtual void trace(Visitor*) { }
 };
 
+// WebCore::ScriptWrappable receives special treatment
+// so as to allow it to be used together with GarbageCollected<T>,
+// even when its user-declared destructor is provided.
+// As it is with Oilpan disabled.
+class ScriptWrappable {
+public:
+    ~ScriptWrappable() { /* user-declared, thus, non-trivial */ }
+};
+
 // Has a non-trivial dtor (user-declared).
 class B {
 public:
     ~B() { }
     void trace(Visitor*) { };
 };
 
 // Has a trivial dtor.
 class C {
 public:
     void trace(Visitor*) { };
 };
 
 } // WebCore namespace
 
 namespace WTF {
 
 template<>
 struct VectorTraits<WebCore::C> {
     static const bool needsDestruction = false;
 };
 
 } // WTF namespace
 
 namespace WebCore {
 
 // Off-heap vectors always need to be finalized.
-class NeedsFinalizer : public A {
+class NeedsFinalizer : public A, public ScriptWrappable {
 public:
     void trace(Visitor*);
 private:
     Vector<Member<A> > m_as;
 };
 
 // On-heap vectors with inlined objects that need destruction
 // need to be finalized.
 class AlsoNeedsFinalizer : public A {
 public:
     void trace(Visitor*);
 private:
     HeapVector<B, 10> m_bs;
 };
 
 // On-heap vectors with no inlined objects never need to be finalized.
-class DoesNotNeedFinalizer : public A {
+class DoesNotNeedFinalizer : public A, public ScriptWrappable {
 public:
     void trace(Visitor*);
 private:
     HeapVector<B> m_bs;
 };
 
 // On-heap vectors with inlined objects that don't need destruction
 // don't need to be finalized.
-class AlsoDoesNotNeedFinalizer : public A {
+class AlsoDoesNotNeedFinalizer : public A, public ScriptWrappable {
 public:
     void trace(Visitor*);
 private:
     HeapVector<Member<A>, 10> m_as;
     HeapVector<C, 10> m_cs;
 };
 
 }
 
 #endif