Deduplicating compositing scrollingCoordinator helper

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

 /*
  * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 252 matching lines @@
     TRACE_LAYER_INVALIDATION(
         layer,
         InspectorLayerInvalidationTrackingEvent::RemovedFromSquashingLayer);
     layersNeedingPaintInvalidation.push_back(layer);
     m_layersChanged = true;
 
     layer->setLostGroupedMapping(false);
   }
 }
 
-static ScrollingCoordinator* scrollingCoordinatorFromLayer(PaintLayer& layer) {
-  Page* page = layer.layoutObject().frame()->page();
-  return (!page) ? nullptr : page->scrollingCoordinator();
-}
-
 void CompositingLayerAssigner::assignLayersToBackingsInternal(
     PaintLayer* layer,
     SquashingState& squashingState,
     Vector<PaintLayer*>& layersNeedingPaintInvalidation) {
   if (requiresSquashing(layer->getCompositingReasons())) {
     SquashingDisallowedReasons reasonsPreventingSquashing =
         getReasonsPreventingSquashing(layer, squashingState);
     if (reasonsPreventingSquashing) {
       layer->setCompositingReasons(layer->getCompositingReasons() |
                                    CompositingReasonSquashingDisallowed);
       layer->setSquashingDisallowedReasons(reasonsPreventingSquashing);
     }
   }
 
   CompositingStateTransitionType compositedLayerUpdate =
       computeCompositedLayerUpdate(layer);
 
   if (m_compositor->allocateOrClearCompositedLayerMapping(
           layer, compositedLayerUpdate)) {
     TRACE_LAYER_INVALIDATION(
         layer, InspectorLayerInvalidationTrackingEvent::NewCompositedLayer);
     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());
       }
     }
   }
 
   // Add this layer to a squashing backing if needed.
   updateSquashingAssignment(layer, squashingState, compositedLayerUpdate,
                             layersNeedingPaintInvalidation);
@@ skipping 37 matching lines @@
   while (PaintLayerStackingNode* curNode = iterator.next())
     assignLayersToBackingsInternal(curNode->layer(), squashingState,
                                    layersNeedingPaintInvalidation);
 
   if (squashingState.hasMostRecentMapping &&
       &squashingState.mostRecentMapping->owningLayer() == layer)
     squashingState.haveAssignedBackingsToEntireSquashingLayerSubtree = true;
 }
 
 }  // namespace blink