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

third_party/WebKit/Source/core/page/Page.cpp

Index: third_party/WebKit/Source/core/page/Page.cpp
diff --git a/third_party/WebKit/Source/core/page/Page.cpp b/third_party/WebKit/Source/core/page/Page.cpp
index 4e1bc08123dadd996f1aee4197958f70142b10b8..ecfd49d77745f84dfeb70b3cf949868ddecda93d 100644
--- a/third_party/WebKit/Source/core/page/Page.cpp
+++ b/third_party/WebKit/Source/core/page/Page.cpp
@@ -173,21 +173,19 @@ ScrollingCoordinator* Page::scrollingCoordinator() {
 }
 
 ClientRectList* Page::nonFastScrollableRects(const LocalFrame* frame) {
+  DisableCompositingQueryAsserts disabler;
   if (ScrollingCoordinator* scrollingCoordinator =
           this->scrollingCoordinator()) {
     // Hits in compositing/iframes/iframe-composited-scrolling.html
-    DisableCompositingQueryAsserts disabler;
     scrollingCoordinator->updateAfterCompositingChangeIfNeeded();
   }
 
-  if (!frame->view()->layerForScrolling())
+  GraphicsLayer* layer =
+      frame->view()->layoutViewportScrollableArea()->layerForScrolling();
+  if (!layer)
     return ClientRectList::create();
-
-  // Now retain non-fast scrollable regions
-  return ClientRectList::create(frame->view()
-                                    ->layerForScrolling()
-                                    ->platformLayer()
-                                    ->nonFastScrollableRegion());
+  return ClientRectList::create(
+      layer->platformLayer()->nonFastScrollableRegion());
 }
 
 void Page::setMainFrame(Frame* mainFrame) {