Remove viewportDefiningElement.

sky/engine/core/rendering/RenderLayerScrollableArea.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 422 matching lines @@
 static bool overflowRequiresScrollbar(EOverflow overflow)
 {
     return overflow == OSCROLL;
 }
 
 static bool overflowDefinesAutomaticScrollbar(EOverflow overflow)
 {
     return overflow == OAUTO || overflow == OOVERLAY;
 }
 
-// This function returns true if the given box requires overflow scrollbars (as
-// opposed to the 'viewport' scrollbars managed by the RenderLayerCompositor).
-// FIXME: we should use the same scrolling machinery for both the viewport and
-// overflow. Currently, we need to avoid producing scrollbars here if they'll be
-// handled externally in the RLC.
-static bool canHaveOverflowScrollbars(const RenderBox& box)
-{
-    return !box.isRenderView() && box.document().viewportDefiningElement() != box.node();
-}
-
 void RenderLayerScrollableArea::updateAfterStyleChange(const RenderStyle* oldStyle)
 {
-    if (!canHaveOverflowScrollbars(box()))
-        return;
-
     if (!m_scrollDimensionsDirty)
         updateScrollableAreaSet(hasScrollableHorizontalOverflow() || hasScrollableVerticalOverflow());
 
     EOverflow overflowX = box().style()->overflowX();
     EOverflow overflowY = box().style()->overflowY();
 
     // To avoid doing a relayout in updateScrollbarsAfterLayout, we try to keep any automatic scrollbar that was already present.
     bool needsHorizontalScrollbar = (hasHorizontalScrollbar() && overflowDefinesAutomaticScrollbar(overflowX)) || overflowRequiresScrollbar(overflowX);
     bool needsVerticalScrollbar = (hasVerticalScrollbar() && overflowDefinesAutomaticScrollbar(overflowY)) || overflowRequiresScrollbar(overflowY);
     setHasHorizontalScrollbar(needsHorizontalScrollbar);
@@ skipping 265 matching lines @@
 void RenderLayerScrollableArea::setTopmostScrollChild(RenderLayer* scrollChild)
 {
     // We only want to track the topmost scroll child for scrollable areas with
     // overlay scrollbars.
     if (!hasOverlayScrollbars())
         return;
     m_nextTopmostScrollChild = scrollChild;
 }
 
 } // namespace blink