[RootLayerScrolls] Annotate non-fast-scroll regions to correct layer

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 1641 matching lines @@
 
   LayoutRect intersect =
       localToAbsolute(box(), intersection(layerBounds, localExposeRect));
   if (intersect.isEmpty() && !layerBounds.isEmpty() &&
       !localExposeRect.isEmpty()) {
     return localToAbsolute(box(), localExposeRect);
   }
   return intersect;
 }
 
+ClientRectList* PaintLayerScrollableArea::nonFastScrollableRects() const {
+  return layer()->nonFastScrollableRects();
+}
+
 void PaintLayerScrollableArea::updateScrollableAreaSet(bool hasOverflow) {
   LocalFrame* frame = box().frame();
   if (!frame)
     return;
 
   FrameView* frameView = frame->view();
   if (!frameView)
     return;
 
   // FIXME: Does this need to be fixed later for OOPI?
@@ skipping 445 matching lines @@
 
 void PaintLayerScrollableArea::DelayScrollOffsetClampScope::
     clampScrollableAreas() {
   for (auto& scrollableArea : *s_needsClamp)
     scrollableArea->clampScrollOffsetAfterOverflowChange();
   delete s_needsClamp;
   s_needsClamp = nullptr;
 }
 
 }  // namespace blink