[oilpan] Move EventHandler to the heap

Source/WebKit/chromium/src/ViewportAnchor.h

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 37 matching lines @@
 // ViewportAnchor provides a way to anchor a viewport origin to a DOM node.
 // In particular, the user supplies the current viewport (in CSS coordinates)
 // and an anchor point (in view coordinates, e.g., (0, 0) == viewport origin,
 // (0.5, 0) == viewport top center). The anchor point tracks the underlying DOM
 // node; as the node moves or the view is resized, the viewport anchor maintains
 // its orientation relative to the node, and the viewport origin maintains its
 // orientation relative to the anchor.
 class ViewportAnchor {
     WTF_MAKE_NONCOPYABLE(ViewportAnchor);
 public:
-    explicit ViewportAnchor(WebCore::EventHandler* eventHandler);
+    explicit ViewportAnchor(HANDLE_FORMAL(WebCore::EventHandler) eventHandler);
 
     void setAnchor(const WebCore::IntRect& viewRect, const WebCore::FloatSize& anchorInViewCoords);
 
     WebCore::IntPoint computeOrigin(const WebCore::IntSize& currentViewSize) const;
 
 private:
+    // FIXME(oilpan): This should be a strong pointer.
     WebCore::EventHandler* m_eventHandler;
 
     WebCore::IntRect m_viewRect;
 
     ANNOTATED_FIELD(WebCore::Persistent<WebCore::Node>, m_anchorNode);
     WebCore::LayoutRect m_anchorNodeBounds;
 
     WebCore::FloatSize m_anchorInViewCoords;
     WebCore::FloatSize m_anchorInNodeCoords;
 };
 
 } // namespace WebKit
 
  #endif