First pass at removing position:fixed.

sky/engine/core/rendering/RenderLayerClipper.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 34 matching lines @@
 #include "core/rendering/RenderLayerClipper.h"
 
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderView.h"
 
 namespace blink {
 
 static void adjustClipRectsForChildren(const RenderObject& renderer, ClipRects& clipRects)
 {
     EPosition position = renderer.style()->position();
-    // A fixed object is essentially the root of its containing block hierarchy, so when
-    // we encounter such an object, we reset our clip rects to the fixedClipRect.
-    if (position == FixedPosition) {
-        clipRects.setPosClipRect(clipRects.fixedClipRect());
-        clipRects.setOverflowClipRect(clipRects.fixedClipRect());
-        clipRects.setFixed(true);
-    } else if (position == RelativePosition) {
+    if (position == RelativePosition) {
         clipRects.setPosClipRect(clipRects.overflowClipRect());
     } else if (position == AbsolutePosition) {
         clipRects.setOverflowClipRect(clipRects.posClipRect());
     }
 }
 
 static void applyClipRects(const ClipRectsContext& context, RenderObject& renderer, LayoutPoint offset, ClipRects& clipRects)
 {
     ASSERT(renderer.hasOverflowClip() || renderer.hasClip());
 
     if (renderer.hasOverflowClip()) {
         ClipRect newOverflowClip = toRenderBox(renderer).overflowClipRect(offset, context.scrollbarRelevancy);
         newOverflowClip.setHasRadius(renderer.style()->hasBorderRadius());
         clipRects.setOverflowClipRect(intersection(newOverflowClip, clipRects.overflowClipRect()));
         if (renderer.isPositioned())
             clipRects.setPosClipRect(intersection(newOverflowClip, clipRects.posClipRect()));
     }
 
     if (renderer.hasClip()) {
         LayoutRect newClip = toRenderBox(renderer).clipRect(offset);
         clipRects.setPosClipRect(intersection(newClip, clipRects.posClipRect()));
         clipRects.setOverflowClipRect(intersection(newClip, clipRects.overflowClipRect()));
-        clipRects.setFixedClipRect(intersection(newClip, clipRects.fixedClipRect()));
     }
 }
 
 RenderLayerClipper::RenderLayerClipper(RenderLayerModelObject& renderer)
     : m_renderer(renderer)
 {
 }
 
 ClipRects* RenderLayerClipper::clipRectsIfCached(const ClipRectsContext& context) const
 {
@@ skipping 202 matching lines @@
     if ((m_renderer.hasOverflowClip() && (context.respectOverflowClip == RespectOverflowClip || !isClippingRoot)) || m_renderer.hasClip()) {
         // This offset cannot use convertToLayerCoords, because sometimes our rootLayer may be across
         // some transformed layer boundary, for example, in the RenderLayerCompositor overlapMap, where
         // clipRects are needed in view space.
         applyClipRects(context, m_renderer, roundedLayoutPoint(m_renderer.localToContainerPoint(FloatPoint(), context.rootLayer->renderer())), clipRects);
     }
 }
 
 static ClipRect backgroundClipRectForPosition(const ClipRects& parentRects, EPosition position)
 {
-    if (position == FixedPosition)
-        return parentRects.fixedClipRect();
-
     if (position == AbsolutePosition)
         return parentRects.posClipRect();
-
     return parentRects.overflowClipRect();
 }
 
 ClipRect RenderLayerClipper::backgroundClipRect(const ClipRectsContext& context) const
 {
     ASSERT(m_renderer.layer()->parent());
     ASSERT(m_renderer.view());
 
     ClipRects parentClipRects;
     if (m_renderer.layer() == context.rootLayer)
@@ skipping 30 matching lines @@
         ASSERT(current);
         if (current->transform() || current->isPaintInvalidationContainer())
             return const_cast<RenderLayer*>(current);
     }
 
     ASSERT_NOT_REACHED();
     return 0;
 }
 
 } // namespace blink