Auto merge of #18462 - mrobinson:cleanup-building-state, r=emilio

Do some minor cleanups in display list building

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components/layout/table.rs

@@ -12,6 +12,7 @@ use block::{ISizeConstraintInput, ISizeConstraintSolution};
 use context::LayoutContext;
 use display_list_builder::{BlockFlowDisplayListBuilding, BorderPaintingMode};
 use display_list_builder::{DisplayListBuildState, EstablishContainingBlock};
+use display_list_builder::StackingContextCollectionState;
 use euclid::Point2D;
 use flow;
 use flow::{BaseFlow, EarlyAbsolutePositionInfo, Flow, FlowClass, ImmutableFlowUtils, OpaqueFlow};
@@ -503,7 +504,7 @@ impl Flow for TableFlow {
         self.block_flow.build_display_list_for_block(state, border_painting_mode);
     }
 
-    fn collect_stacking_contexts(&mut self, state: &mut DisplayListBuildState) {
+    fn collect_stacking_contexts(&mut self, state: &mut StackingContextCollectionState) {
         self.block_flow.collect_stacking_contexts_for_block(state, EstablishContainingBlock::Yes);
     }