Blink GC plugin: Don't check conditions on invalid compilation units.

tools/clang/blink_gc_plugin/tests/crash_on_invalid.h

Index: tools/clang/blink_gc_plugin/tests/crash_on_invalid.h
diff --git a/tools/clang/blink_gc_plugin/tests/crash_on_invalid.h b/tools/clang/blink_gc_plugin/tests/crash_on_invalid.h
new file mode 100644
index 0000000000000000000000000000000000000000..a77d0973c5571fed92f637bd45ad731b028f9dcb
--- /dev/null
+++ b/tools/clang/blink_gc_plugin/tests/crash_on_invalid.h
@@ -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.
+
+// Regression test for http://crbug.com/421958
+
+#ifndef CRASH_ON_INVALID_H_
+#define CRASH_ON_INVALID_H_
+
+namespace blink {
+
+class Visitor;
+class GamepadCommon {};
+class ScriptWrappable {};
+
+class Gamepad final : public GarbageCollectedFinalized<Gamepad>,
+                      public GamepadCommon,
+                      public ScriptWrappable {
+public:
+    virtual const WrapperTypeInfo *wrapperTypeInfo() const {}
+    void trace(Visitor *);
+};
+
+}
+
+#endif