Scroll sticky elements into view.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 655 matching lines @@
                         UseTransforms | TraverseDocumentBoundaries)
                     .boundingBox());
           } else {
             parentBox = nullptr;
           }
         }
       }
     }
   }
 
-  // If we are fixed-position, it is useless to scroll the parent.
-  if (hasLayer() && layer()->scrollsWithViewport())
+  // If we are fixed-position and scroll with the viewport, it is useless to
+  // scroll the parent.
+  if (style()->position() == FixedPosition && hasLayer() &&
+      layer()->scrollsWithViewport()) {
     return;
+  }
 
   if (frame()->page()->autoscrollController().autoscrollInProgress())
     parentBox = enclosingScrollableBox();
 
   if (parentBox)
     parentBox->scrollRectToVisible(newRect, alignX, alignY, scrollType,
                                    makeVisibleInVisualViewport);
 }
 
 void LayoutBox::absoluteRects(Vector<IntRect>& rects,
@@ skipping 4955 matching lines @@
   LayoutRect rect = frameRect();
 
   LayoutBlock* block = containingBlock();
   if (block)
     block->adjustChildDebugRect(rect);
 
   return rect;
 }
 
 }  // namespace blink