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

tools/clang/blink_gc_plugin/tests/class_requires_finalization_mixin.cpp

Index: tools/clang/blink_gc_plugin/tests/class_requires_finalization_mixin.cpp
diff --git a/tools/clang/blink_gc_plugin/tests/class_requires_finalization_mixin.cpp b/tools/clang/blink_gc_plugin/tests/class_requires_finalization_mixin.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c1a9ec7187bd405b8b4b27991191195fe88f7a9e
--- /dev/null
+++ b/tools/clang/blink_gc_plugin/tests/class_requires_finalization_mixin.cpp
@@ -0,0 +1,26 @@
+// 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.
+
+#include "class_requires_finalization_mixin.h"
+
+namespace WebCore {
+
+void Mixin::trace(Visitor* visitor)
+{
+    visitor->trace(m_onHeap);
+}
+
+void NeedsFinalizer::trace(Visitor* visitor)
+{
+    visitor->trace(m_obj);
+    Mixin::trace(visitor);
+}
+
+void HasFinalizer::trace(Visitor* visitor)
+{
+    visitor->trace(m_obj);
+    Mixin::trace(visitor);
+}
+
+}