Reset all EventHandler data members in EventHandler::clear()

Source/core/page/EventHandler.h

 /*
  * Copyright (C) 2006, 2007, 2009, 2010, 2011 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
@@ skipping 304 matching lines @@
 
     bool handleScrollGestureOnResizer(Node*, const PlatformGestureEvent&);
 
     bool passScrollGestureEventToWidget(const PlatformGestureEvent&, RenderObject*);
     bool sendScrollEventToView(const PlatformGestureEvent&, const FloatSize&);
 
     AutoscrollController* autoscrollController() const;
     bool panScrollInProgress() const;
     void setLastKnownMousePosition(const PlatformMouseEvent&);
 
+    // NOTE: If adding a new field to this class please ensure that it is
+    // cleared in |EventHandler::clear()|.
+
     LocalFrame* const m_frame;
 
     bool m_mousePressed;
     bool m_capturesDragging;
     RefPtrWillBeMember<Node> m_mousePressNode;
 
     bool m_mouseDownMayStartSelect;
     bool m_mouseDownMayStartDrag;
     bool m_mouseDownWasSingleClickInSelection;
     enum SelectionInitiationState { HaveNotStartedSelection, PlacedCaret, ExtendedSelection };
@@ skipping 65 matching lines @@
     bool m_longTapShouldInvokeContextMenu;
 
     Timer<EventHandler> m_activeIntervalTimer;
     double m_lastShowPressTimestamp;
     RefPtrWillBeMember<Element> m_lastDeferredTapElement;
 };
 
 } // namespace blink
 
 #endif // EventHandler_h