Support registering and dispatching passive event listeners.

third_party/WebKit/Source/core/events/Event.h

 /*
  * Copyright (C) 2001 Peter Kelly (pmk@post.com)
  * Copyright (C) 2001 Tobias Anton (anton@stud.fbi.fh-darmstadt.de)
  * Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 151 matching lines @@
     // These events lack a DOM interface.
     virtual bool isClipboardEvent() const;
     virtual bool isBeforeTextInsertedEvent() const;
 
     virtual bool isBeforeUnloadEvent() const;
 
     bool propagationStopped() const { return m_propagationStopped || m_immediatePropagationStopped; }
     bool immediatePropagationStopped() const { return m_immediatePropagationStopped; }
 
     bool defaultPrevented() const { return m_defaultPrevented; }
-    virtual void preventDefault()
-    {
-        if (m_cancelable)
-            m_defaultPrevented = true;
-    }
+    virtual void preventDefault();
     void setDefaultPrevented(bool defaultPrevented) { m_defaultPrevented = defaultPrevented; }
 
     bool defaultHandled() const { return m_defaultHandled; }
     void setDefaultHandled() { m_defaultHandled = true; }
 
     bool cancelBubble() const { return m_cancelBubble; }
     void setCancelBubble(bool cancel) { m_cancelBubble = cancel; }
 
     Event* underlyingEvent() const { return m_underlyingEvent.get(); }
     void setUnderlyingEvent(PassRefPtrWillBeRawPtr<Event>);
 
     EventPath& eventPath() { ASSERT(m_eventPath); return *m_eventPath; }
     void initEventPath(Node&);
 
     WillBeHeapVector<RefPtrWillBeMember<EventTarget>> path(ScriptState*) const;
 
     bool isBeingDispatched() const { return eventPhase(); }
 
     // Events that must not leak across isolated world, similar to how
     // ErrorEvent behaves, can override this method.
     virtual bool canBeDispatchedInWorld(const DOMWrapperWorld&) const { return true; }
 
     virtual PassRefPtrWillBeRawPtr<EventDispatchMediator> createMediator();
 
     bool isTrusted() const { return m_isTrusted; }
     void setTrusted(bool value) { m_isTrusted = value; }
 
+    void setHandlingPassive(bool value) { m_handlingPassive = value; }
+
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     Event();
     Event(const AtomicString& type, bool canBubble, bool cancelable);
     Event(const AtomicString& type, bool canBubble, bool cancelable, double platformTimeStamp);
     Event(const AtomicString& type, const EventInit&);
 
     virtual void receivedTarget();
     bool dispatched() const { return m_target; }
 
     void setCanBubble(bool bubble) { m_canBubble = bubble; }
 
 private:
     AtomicString m_type;
     unsigned m_canBubble:1;
     unsigned m_cancelable:1;
 
     unsigned m_propagationStopped:1;
     unsigned m_immediatePropagationStopped:1;
     unsigned m_defaultPrevented:1;
     unsigned m_defaultHandled:1;
     unsigned m_cancelBubble:1;
     unsigned m_isTrusted : 1;
+    unsigned m_handlingPassive : 1;
 
     unsigned short m_eventPhase;
     RefPtrWillBeMember<EventTarget> m_currentTarget;
     RefPtrWillBeMember<EventTarget> m_target;
     DOMTimeStamp m_createTime;
     RefPtrWillBeMember<Event> m_underlyingEvent;
     OwnPtrWillBeMember<EventPath> m_eventPath;
     // The monotonic platform time in seconds, for input events it is the
     // event timestamp provided by the host OS and reported in the original
     // WebInputEvent instance.
     double m_platformTimeStamp;
 };
 
 #define DEFINE_EVENT_TYPE_CASTS(typeName) \
     DEFINE_TYPE_CASTS(typeName, Event, event, event->is##typeName(), event.is##typeName())
 
 } // namespace blink
 
 #endif // Event_h