[v8 gc] Introduce a base class for all objects that can have pending activity

third_party/WebKit/Source/bindings/core/v8/ActiveScriptWrappable.h

+// Copyright 2016 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 ActiveScriptWrappable_h
+#define ActiveScriptWrappable_h
+
+#include "core/CoreExport.h"
+#include "wtf/Noncopyable.h"
+
+namespace blink {
+
+class ScriptWrappable;
+
+/**
+ * Classes deriving from ActiveScriptWrappable will be registered in a
+ * thread-specific list. They keep their wrappers and dependant objects alive
+ * as long as they have pending activity.
+ */
+class CORE_EXPORT ActiveScriptWrappable {
+    WTF_MAKE_NONCOPYABLE(ActiveScriptWrappable);
+public:
+    explicit ActiveScriptWrappable(ScriptWrappable*);
+
+    virtual bool hasPendingActivity() const = 0;
+
+    ScriptWrappable* toScriptWrappable() const;
+
+protected:
+    virtual ~ActiveScriptWrappable();
+
+private:
+    ScriptWrappable* m_scriptWrappable;
+};
+
+} // namespace blink
+
+#endif // ActiveScriptWrappable_h