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

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 13 matching lines @@
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/frame/FrameView.h"
 
 #include "core/HTMLNames.h"
 #include "core/MediaTypeNames.h"
 #include "core/animation/DocumentAnimations.h"
 #include "core/css/FontFaceSet.h"
 #include "core/dom/AXObjectCache.h"
+#include "core/dom/ClientRectList.h"
 #include "core/dom/DOMNodeIds.h"
 #include "core/dom/ElementVisibilityObserver.h"
 #include "core/dom/Fullscreen.h"
 #include "core/dom/IntersectionObserverCallback.h"
 #include "core/dom/IntersectionObserverController.h"
 #include "core/dom/IntersectionObserverInit.h"
 #include "core/dom/ResizeObserverController.h"
 #include "core/dom/StyleChangeReason.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/editing/EditingUtilities.h"
@@ skipping 4329 matching lines @@
     setScrollOffset(
         ScrollOffset(exposeRect.x().toFloat(), exposeRect.y().toFloat()),
         scrollType);
   }
 
   // Scrolling the FrameView cannot change the input rect's location relative to
   // the document.
   return rectInContent;
 }
 
+ClientRectList* FrameView::nonFastScrollableRects() const {
+  if (!layerForScrolling())
+    return ClientRectList::create();
+  return ClientRectList::create(
+      layerForScrolling()->platformLayer()->nonFastScrollableRegion());
+}
+
 IntRect FrameView::scrollCornerRect() const {
   IntRect cornerRect;
 
   if (hasOverlayScrollbars())
     return cornerRect;
 
   if (horizontalScrollbar() && width() - horizontalScrollbar()->width() > 0) {
     cornerRect.unite(IntRect(shouldPlaceVerticalScrollbarOnLeft()
                                  ? 0
                                  : horizontalScrollbar()->width(),
@@ skipping 669 matching lines @@
     std::unique_ptr<CompositorAnimationTimeline> timeline) {
   m_animationTimeline = std::move(timeline);
 }
 
 void FrameView::setAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   m_animationHost = std::move(host);
 }
 
 }  // namespace blink