Check that classes with non-trivial destructors have finalization support.

tools/clang/blink_gc_plugin/tests/class_requires_finalization_mixin.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_MIXIN_H_
+#define CLASS_REQUIRES_FINALIZATION_MIXIN_H_
+
+#include "heap/stubs.h"
+
+namespace WebCore {
+
+class OffHeap : public RefCounted<OffHeap> { };
+class OnHeap : public GarbageCollected<OnHeap> { };
+
+class Mixin : public GarbageCollectedMixin {
+public:
+    void trace(Visitor*);
+private:
+    RefPtr<OffHeap> m_offHeap; // Requires finalization
+    Member<OnHeap> m_onHeap;
+};
+
+class NeedsFinalizer : public GarbageCollected<NeedsFinalizer>, public Mixin {
+    USING_GARBAGE_COLLECTED_MIXIN(NeedsFinalizer);
+public:
+    void trace(Visitor*);
+private:
+    Member<OnHeap> m_obj;
+};
+
+class HasFinalizer : public GarbageCollectedFinalized<HasFinalizer>,
+                     public Mixin {
+    USING_GARBAGE_COLLECTED_MIXIN(HasFinalizer);
+public:
+    void trace(Visitor*);
+private:
+    Member<OnHeap> m_obj;
+};
+
+}
+
+#endif