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

third_party/WebKit/Source/core/layout/LayoutView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 344 matching lines @@
         }
     }
 
     // If a container was specified, and was not 0 or the LayoutView, then we
     // should have found it by now unless we're traversing to a parent document.
     DCHECK(!ancestorToStopAt || ancestorToStopAt == this || container);
 
     if ((!ancestorToStopAt || container) && shouldUseTransformFromContainer(container)) {
         TransformationMatrix t;
         getTransformFromContainer(container, LayoutSize(), t);
-        geometryMap.push(this, t, HasTransform, offsetForFixedPosition);
+        geometryMap.push(this, t, ContainsFixedPosition, offsetForFixedPosition);
     } else {
         geometryMap.push(this, offset, 0, offsetForFixedPosition);
     }
 
     return container;
 }
 
 void LayoutView::mapAncestorToLocal(const LayoutBoxModelObject* ancestor, TransformState& transformState, MapCoordinatesFlags mode) const
 {
     if (this == ancestor)
@@ skipping 624 matching lines @@
     // of this override. All frame scrolling should be handled by
     // ViewportScrollCallback.
 
     if (!frameView())
         return ScrollResult(false, false, delta.width(), delta.height());
 
     return frameView()->getScrollableArea()->userScroll(granularity, delta);
 }
 
 } // namespace blink