Deduplicating compositing scrollingCoordinator helper

third_party/WebKit/Source/core/layout/compositing/CompositingLayerAssigner.cpp

Index: third_party/WebKit/Source/core/layout/compositing/CompositingLayerAssigner.cpp
diff --git a/third_party/WebKit/Source/core/layout/compositing/CompositingLayerAssigner.cpp b/third_party/WebKit/Source/core/layout/compositing/CompositingLayerAssigner.cpp
index c146c8bbb7cbf6abdb39ed4929975891d8bbe732..6d2527a217e500036793e8898ff3ea746130b291 100644
--- a/third_party/WebKit/Source/core/layout/compositing/CompositingLayerAssigner.cpp
+++ b/third_party/WebKit/Source/core/layout/compositing/CompositingLayerAssigner.cpp
@@ -270,11 +270,6 @@ void CompositingLayerAssigner::updateSquashingAssignment(
   }
 }
 
-static ScrollingCoordinator* scrollingCoordinatorFromLayer(PaintLayer& layer) {
-  Page* page = layer.layoutObject().frame()->page();
-  return (!page) ? nullptr : page->scrollingCoordinator();
-}
-
 void CompositingLayerAssigner::assignLayersToBackingsInternal(
     PaintLayer* layer,
     SquashingState& squashingState,
@@ -299,7 +294,7 @@ void CompositingLayerAssigner::assignLayersToBackingsInternal(
     layersNeedingPaintInvalidation.push_back(layer);
     m_layersChanged = true;
     if (ScrollingCoordinator* scrollingCoordinator =
-            scrollingCoordinatorFromLayer(*layer)) {
+            CompositedLayerMapping::scrollingCoordinatorFromLayer(*layer)) {
       if (layer->layoutObject().style()->hasViewportConstrainedPosition()) {
         scrollingCoordinator->frameViewFixedObjectsDidChange(
             layer->layoutObject().view()->frameView());