--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/dom/ActiveDOMObject.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ *
+ */
+
+#ifndef ActiveDOMObject_h
+#define ActiveDOMObject_h
+
+#include <wtf/Assertions.h>
+
+namespace WebCore {
+
+    class ScriptExecutionContext;
+
+    class ActiveDOMObject {
+    public:
+        ActiveDOMObject(ScriptExecutionContext*, void* upcastPointer);
+
+        ScriptExecutionContext* scriptExecutionContext() const { return m_scriptExecutionContext; }
+        virtual bool hasPendingActivity() const;
+
+        virtual void contextDestroyed();
+
+        // canSuspend() is used by the caller if there is a choice between suspending and stopping.
+        // For example, a page won't be suspended and placed in the back/forward cache if it has
+        // the objects that can not be suspended.
+        // However, 'suspend' can be called even if canSuspend() would return 'false'. That
+        // happens in step-by-step JS debugging for example - in this case it would be incorrect
+        // to stop the object. Exact semantics of suspend is up to the object then.
+        virtual bool canSuspend() const;
+        virtual void suspend();
+        virtual void resume();
+        virtual void stop();
+
+        template<class T> void setPendingActivity(T* thisObject)
+        {
+            ASSERT(thisObject == this);
+            thisObject->ref();
+            m_pendingActivityCount++;
+        }
+
+        template<class T> void unsetPendingActivity(T* thisObject)
+        {
+            ASSERT(m_pendingActivityCount > 0);
+            --m_pendingActivityCount;
+            thisObject->deref();
+        }
+
+    protected:
+        virtual ~ActiveDOMObject();
+
+    private:
+        ScriptExecutionContext* m_scriptExecutionContext;
+        unsigned m_pendingActivityCount;
+    };
+
+} // namespace WebCore
+
+#endif // ActiveDOMObject_h