Blink GC plugin: Ensure that classes with virtual trace methods always have vtables for their left-…

tools/clang/blink_gc_plugin/tests/base_class_must_define_virtual_trace.h

Index: tools/clang/blink_gc_plugin/tests/base_class_must_define_virtual_trace.h
diff --git a/tools/clang/blink_gc_plugin/tests/base_class_must_define_virtual_trace.h b/tools/clang/blink_gc_plugin/tests/base_class_must_define_virtual_trace.h
new file mode 100644
index 0000000000000000000000000000000000000000..16558bb85084fb6884ae8413ddceae543b52d4a5
--- /dev/null
+++ b/tools/clang/blink_gc_plugin/tests/base_class_must_define_virtual_trace.h
@@ -0,0 +1,38 @@
+// 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 BASE_CLASS_MUST_DEFINE_VIRTUAL_TRACE_H_
+#define BASE_CLASS_MUST_DEFINE_VIRTUAL_TRACE_H_
+
+#include "heap/stubs.h"
+
+namespace blink {
+
+class PartBase {
+    DISALLOW_ALLOCATION();
+    // Missing virtual trace.
+};
+
+class PartDerived : public PartBase {
+    DISALLOW_ALLOCATION();
+public:
+    virtual void trace(Visitor*);
+};
+
+class HeapBase : public GarbageCollected<HeapBase> {
+    // Missing virtual trace.
+};
+
+
+class HeapDerived : public HeapBase {
+public:
+    virtual void trace(Visitor*);
+private:
+    PartDerived m_part;
+};
+
+
+}
+
+#endif