Ensure that we consistently check contains: paint for fixed position containment.

third_party/WebKit/Source/core/paint/PaintLayer.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 828 matching lines @@
 {
     if (!layoutObject()->hasTransformRelatedProperty())
         return FloatPoint();
 
     const LayoutRect borderBox = toLayoutBox(layoutObject())->borderBoxRect();
     const ComputedStyle& style = layoutObject()->styleRef();
 
     return FloatPoint(floatValueForLength(style.perspectiveOriginX(), borderBox.width().toFloat()), floatValueForLength(style.perspectiveOriginY(), borderBox.height().toFloat()));
 }
 
-static inline bool isContainerForFixedPositioned(PaintLayer* layer)
-{
-    return layer->isRootLayer() || layer->hasTransformRelatedProperty();
-}
-
-static inline bool isContainerForPositioned(PaintLayer* layer)
-{
-    // FIXME: This is not in sync with containingBlock.
-    // LayoutObject::canContainFixedPositionObjects() should probably be used
-    // instead.
-    LayoutBoxModelObject* layerlayoutObject = layer->layoutObject();
-    return layer->isRootLayer() || layerlayoutObject->isPositioned() || layer->hasTransformRelatedProperty() || layerlayoutObject->style()->containsPaint();
-}
-
 PaintLayer* PaintLayer::containingLayerForOutOfFlowPositioned(const PaintLayer* ancestor, bool* skippedAncestor) const
 {
     ASSERT(!ancestor || skippedAncestor); // If we have specified an ancestor, surely the caller needs to know whether we skipped it.
     if (skippedAncestor)
         *skippedAncestor = false;
     if (layoutObject()->style()->position() == FixedPosition) {
         PaintLayer* curr = parent();
-        while (curr && !isContainerForFixedPositioned(curr)) {
+        while (curr && !curr->layoutObject()->canContainFixedPositionObjects()) {
             if (skippedAncestor && curr == ancestor)
                 *skippedAncestor = true;
             curr = curr->parent();
         }
 
         return curr;
     }
 
     PaintLayer* curr = parent();
-    while (curr && !isContainerForPositioned(curr)) {
+    while (curr && !curr->layoutObject()->canContainAbsolutePositionObjects()) {
         if (skippedAncestor && curr == ancestor)
             *skippedAncestor = true;
         curr = curr->parent();
     }
 
     return curr;
 }
 
 PaintLayer* PaintLayer::enclosingTransformedAncestor() const
 {
@@ skipping 2057 matching lines @@
 
 void showLayerTree(const blink::LayoutObject* layoutObject)
 {
     if (!layoutObject) {
         fprintf(stderr, "Cannot showLayerTree. Root is (nil)\n");
         return;
     }
     showLayerTree(layoutObject->enclosingLayer());
 }
 #endif