Chromium roll (https://codereview.chromium.org/976353002)

tools/clang/blink_gc_plugin/tests/traceimpl_omitted_trace.h

Index: tools/clang/blink_gc_plugin/tests/traceimpl_omitted_trace.h
diff --git a/tools/clang/blink_gc_plugin/tests/traceimpl_omitted_trace.h b/tools/clang/blink_gc_plugin/tests/traceimpl_omitted_trace.h
new file mode 100644
index 0000000000000000000000000000000000000000..3c5e9559527d397ab01076a088ff1c234d6db89a
--- /dev/null
+++ b/tools/clang/blink_gc_plugin/tests/traceimpl_omitted_trace.h
@@ -0,0 +1,47 @@
+// Copyright 2015 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 TRACEIMPL_OMITTED_TRACE_H_
+#define TRACEIMPL_OMITTED_TRACE_H_
+
+#include "heap/stubs.h"
+
+namespace blink {
+
+class A : public GarbageCollected<A> {
+ public:
+  virtual void trace(Visitor* visitor) { traceImpl(visitor); }
+  virtual void trace(InlinedGlobalMarkingVisitor visitor) {
+    traceImpl(visitor);
+  }
+
+ private:
+  template <typename VisitorDispatcher>
+  void traceImpl(VisitorDispatcher visitor) {}
+};
+
+class B : public A {
+  // trace() isn't necessary because we've got nothing to trace here.
+};
+
+class C : public B {
+ public:
+  void trace(Visitor* visitor) override { traceImpl(visitor); }
+  void trace(InlinedGlobalMarkingVisitor visitor) override {
+    traceImpl(visitor);
+  }
+
+ private:
+  template <typename VisitorDispatcher>
+  void traceImpl(VisitorDispatcher visitor) {
+    // B::trace() is actually A::trace(), and in certain cases we only get
+    // limited information like "there is a function call that will be resolved
+    // to A::trace()". We still want to mark B as traced.
+    B::trace(visitor);
+  }
+};
+
+}
+
+#endif  // TRACEIMPL_OMITTED_TRACE_H_