Move computation of RenderLayer::isUnclippedDescendant into CompositingPropertyUpdater

Source/core/rendering/compositing/RenderLayerCompositor.h

 /*
  * Copyright (C) 2009 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 83 matching lines @@
 
     bool rootShouldAlwaysComposite() const;
 
     // Copy the accelerated compositing related flags from Settings
     void updateAcceleratedCompositingSettings();
 
     // Called when the layer hierarchy needs to be updated (compositing layers have been
     // created, destroyed or re-parented).
     void setCompositingLayersNeedRebuild();
 
-    // Updating properties required for determining if compositing is necessary.
-    void updateCompositingRequirementsState();

[Ian Vollick, 2014/06/01 19:25:36]

Awesome!

-    void setNeedsUpdateCompositingRequirementsState() { m_needsUpdateCompositingRequirementsState = true; }
-
     // Used to indicate that a compositing update will be needed for the next frame that gets drawn.
     void setNeedsCompositingUpdate(CompositingUpdateType);
 
     enum UpdateLayerCompositingStateOptions {
         Normal,
         UseChickenEggHacks, // Use this to trigger temporary chicken-egg hacks. See crbug.com/339892.
     };
 
     // Update the compositing dirty bits, based on the compositing-impacting properties of the layer.
     void updateLayerCompositingState(RenderLayer*, UpdateLayerCompositingStateOptions = Normal);
@@ skipping 55 matching lines @@
     void rootFixedBackgroundsChanged();
 
     bool scrollingLayerDidChange(RenderLayer*);
 
     String layerTreeAsText(LayerTreeFlags);
 
     GraphicsLayer* layerForHorizontalScrollbar() const { return m_layerForHorizontalScrollbar.get(); }
     GraphicsLayer* layerForVerticalScrollbar() const { return m_layerForVerticalScrollbar.get(); }
     GraphicsLayer* layerForScrollCorner() const { return m_layerForScrollCorner.get(); }
 
-    void addOutOfFlowPositionedLayer(RenderLayer*);
-    void removeOutOfFlowPositionedLayer(RenderLayer*);
-
     void resetTrackedRepaintRects();
     void setTracksRepaints(bool);
 
     void setNeedsToRecomputeCompositingRequirements() { m_needsToRecomputeCompositingRequirements = true; }
 
     virtual String debugName(const GraphicsLayer*) OVERRIDE;
 
     void updateStyleDeterminedCompositingReasons(RenderLayer*);
 
     // Whether the layer could ever be composited.
@@ skipping 77 matching lines @@
     bool m_compositingLayersNeedRebuild;
 
     // The root layer doesn't composite if it's a non-scrollable frame.
     // So, after a layout we set this dirty bit to know that we need
     // to recompute whether the root layer should composite even if
     // none of its descendants composite.
     // FIXME: Get rid of all the callers of setCompositingModeEnabled
     // except the one in updateIfNeeded, then rename this to
     // m_compositingDirty.
     bool m_rootShouldAlwaysCompositeDirty;
-    bool m_needsUpdateCompositingRequirementsState;
     bool m_needsUpdateFixedBackground;
     bool m_isTrackingRepaints; // Used for testing.
 
     RootLayerAttachment m_rootLayerAttachment;
 
     // Enclosing container layer, which clips for iframe content
     OwnPtr<GraphicsLayer> m_containerLayer;
     OwnPtr<GraphicsLayer> m_scrollLayer;
 
-    // This is used in updateCompositingRequirementsState to avoid full tree
-    // walks while determining if layers have unclipped descendants.
-    HashSet<RenderLayer*> m_outOfFlowPositionedLayers;
-
     // Enclosing layer for overflow controls and the clipping layer
     OwnPtr<GraphicsLayer> m_overflowControlsHostLayer;
 
     // Layers for overflow controls
     OwnPtr<GraphicsLayer> m_layerForHorizontalScrollbar;
     OwnPtr<GraphicsLayer> m_layerForVerticalScrollbar;
     OwnPtr<GraphicsLayer> m_layerForScrollCorner;
 #if USE(RUBBER_BANDING)
     OwnPtr<GraphicsLayer> m_layerForOverhangShadow;
 #endif
 };
 
 } // namespace WebCore
 
 #endif // RenderLayerCompositor_h