Support an Event Path API

Source/core/dom/EventContext.h

 /*
  * Copyright (C) 2010 Google 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
@@ skipping 35 matching lines @@
     Node* node() const { return m_node.get(); }
     EventTarget* target() const { return m_target.get(); }
     bool currentTargetSameAsTarget() const { return m_currentTarget.get() == m_target.get(); }
     virtual void handleLocalEvents(Event*) const;
     virtual bool isMouseOrFocusEventContext() const;
     virtual bool isTouchEventContext() const;
 
 protected:
 #ifndef NDEBUG
     bool isUnreachableNode(EventTarget*);
-    bool isReachable(Node*) const;
 #endif
     RefPtr<Node> m_node;
     RefPtr<EventTarget> m_currentTarget;
     RefPtr<EventTarget> m_target;
 };
 
 typedef Vector<OwnPtr<EventContext>, 32> EventPath;
 
 class MouseOrFocusEventContext : public EventContext {
 public:
@@ skipping 33 matching lines @@
 inline TouchEventContext* toTouchEventContext(EventContext* eventContext)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!eventContext || eventContext->isTouchEventContext());
     return static_cast<TouchEventContext*>(eventContext);
 }
 
 #ifndef NDEBUG
 inline bool EventContext::isUnreachableNode(EventTarget* target)
 {
     // FIXME: Checks also for SVG elements.
-    return target && target->toNode() && !target->toNode()->isSVGElement() && !isReachable(target->toNode());
-}
-
-inline bool EventContext::isReachable(Node* target) const
-{
-    ASSERT(target);
-    TreeScope* targetScope = target->treeScope();
-    for (TreeScope* scope = m_node->treeScope(); scope; scope = scope->parentTreeScope()) {
-        if (scope == targetScope)
-            return true;
-    }
-    return false;
+    return target && target->toNode() && !target->toNode()->isSVGElement() && !target->toNode()->treeScope()->isInclusiveAncestorOf(m_node->treeScope());
 }
 #endif
 
 inline void MouseOrFocusEventContext::setRelatedTarget(PassRefPtr<EventTarget> relatedTarget)
 {
     ASSERT(!isUnreachableNode(relatedTarget.get()));
     m_relatedTarget = relatedTarget;
 }
 
 }
 
 #endif // EventContext_h