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 255 matching lines @@
     TRACE_LAYER_INVALIDATION(
         layer,
         InspectorLayerInvalidationTrackingEvent::kRemovedFromSquashingLayer);
     layers_needing_paint_invalidation.push_back(layer);
     layers_changed_ = true;
 
     layer->SetLostGroupedMapping(false);
   }
 }
 
-static ScrollingCoordinator* ScrollingCoordinatorFromLayer(PaintLayer& layer) {
-  Page* page = layer.GetLayoutObject().GetFrame()->GetPage();
-  return (!page) ? nullptr : page->GetScrollingCoordinator();
-}
-
 void CompositingLayerAssigner::AssignLayersToBackingsInternal(
     PaintLayer* layer,
     SquashingState& squashing_state,
     Vector<PaintLayer*>& layers_needing_paint_invalidation) {
   if (RequiresSquashing(layer->GetCompositingReasons())) {
     SquashingDisallowedReasons reasons_preventing_squashing =
         GetReasonsPreventingSquashing(layer, squashing_state);
     if (reasons_preventing_squashing) {
       layer->SetCompositingReasons(layer->GetCompositingReasons() |
                                    kCompositingReasonSquashingDisallowed);
       layer->SetSquashingDisallowedReasons(reasons_preventing_squashing);
     }
   }
 
   CompositingStateTransitionType composited_layer_update =
       ComputeCompositedLayerUpdate(layer);
 
   if (compositor_->AllocateOrClearCompositedLayerMapping(
           layer, composited_layer_update)) {
     TRACE_LAYER_INVALIDATION(
         layer, InspectorLayerInvalidationTrackingEvent::kNewCompositedLayer);
     layers_needing_paint_invalidation.push_back(layer);
     layers_changed_ = true;
     if (ScrollingCoordinator* scrolling_coordinator =
-            ScrollingCoordinatorFromLayer(*layer)) {
+            layer->GetScrollingCoordinator()) {
       if (layer->GetLayoutObject().Style()->HasViewportConstrainedPosition()) {
         scrolling_coordinator->FrameViewFixedObjectsDidChange(
             layer->GetLayoutObject().View()->GetFrameView());
       }
     }
   }
 
   // Add this layer to a squashing backing if needed.
   UpdateSquashingAssignment(layer, squashing_state, composited_layer_update,
                             layers_needing_paint_invalidation);
@@ skipping 38 matching lines @@
     AssignLayersToBackingsInternal(cur_node->Layer(), squashing_state,
                                    layers_needing_paint_invalidation);
 
   if (squashing_state.has_most_recent_mapping &&
       &squashing_state.most_recent_mapping->OwningLayer() == layer)
     squashing_state.have_assigned_backings_to_entire_squashing_layer_subtree =
         true;
 }
 
 }  // namespace blink