Make warn-unneeded-finalizer warning usable.

tools/clang/blink_gc_plugin/tests/class_does_not_require_finalization.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_DOES_NOT_REQUIRE_FINALIZATION_BASE_H_
 #define CLASS_DOES_NOT_REQUIRE_FINALIZATION_BASE_H_
 
 #include "heap/stubs.h"
 
 namespace blink {
@@ skipping 15 matching lines @@
 public:
     ~DoesNotNeedFinalizer2();
     void trace(Visitor*);
 };
 
 class HasEmptyDtor {
 public:
     virtual ~HasEmptyDtor() { }
 };
 
-class DoesNotNeedFinalizer3
-    : public GarbageCollectedFinalized<DoesNotNeedFinalizer3>,
+// If there are any virtual destructors involved, give up.
+
+class DoesNeedFinalizer2
+    : public GarbageCollectedFinalized<DoesNeedFinalizer2>,
       public HasEmptyDtor {
 public:
     void trace(Visitor*);
 };
 
 }
 
 #endif