Global cycle detection analysis.

tools/clang/blink_gc_plugin/tests/cycle_sub.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 BASE_REQUIRES_TRACING_H_
-#define BASE_REQUIRES_TRACING_H_
+#ifndef CYCLE_SUB_H_
+#define CYCLE_SUB_H_
 
 #include "heap/stubs.h"
 
 namespace WebCore {
 
-class A : public GarbageCollected<A> {
+class C;
+
+// This contains a leaking cycle:
+// C -per-> A -sub-> B -ref-> C
+
+class A : public GarbageCollectedFinalized<A> {
 public:
-    virtual void trace(Visitor*);
+    virtual void trace(Visitor*) {}
 };
 
 class B : public A {
-    // Does not need trace
+public:
+    virtual void trace(Visitor*);
+private:
+    RefPtr<C> m_c;
 };
 
-class C : public B {
-public:
-    void trace(Visitor*);
+class C : public RefCounted<C> {
 private:
-    Member<A> m_a;
-};
-
-class D : public C {
-public:
-    void trace(Visitor*);
-private:
-    Member<A> m_a;
+    Persistent<A> m_a;
 };
 
 }
 
 #endif