Do not promote position sticky or fixed elements unless they move with scroll.

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.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@gmail.com>
@@ skipping 1543 matching lines @@
     d->m_stickyConstraintsMap.clear();
   }
 }
 
 void PaintLayerScrollableArea::invalidateStickyConstraintsFor(
     PaintLayer* layer,
     bool needsCompositingUpdate) {
   if (PaintLayerScrollableAreaRareData* d = rareData()) {
     d->m_stickyConstraintsMap.remove(layer);
     if (needsCompositingUpdate &&
-        layer->layoutObject().style()->position() == EPosition::kSticky)
+        layer->layoutObject().style()->hasStickyConstrainedPosition())
       layer->setNeedsCompositingInputsUpdate();
   }
 }
 
 IntSize PaintLayerScrollableArea::offsetFromResizeCorner(
     const IntPoint& absolutePoint) const {
   // Currently the resize corner is either the bottom right corner or the bottom
   // left corner.
   // FIXME: This assumes the location is 0, 0. Is this guaranteed to always be
   // the case?
@@ skipping 574 matching lines @@
 
 void PaintLayerScrollableArea::DelayScrollOffsetClampScope::
     clampScrollableAreas() {
   for (auto& scrollableArea : *s_needsClamp)
     scrollableArea->clampScrollOffsetAfterOverflowChange();
   delete s_needsClamp;
   s_needsClamp = nullptr;
 }
 
 }  // namespace blink