Make DisplayItemClient an interface

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.h

 /*
  * Copyright (C) 2009, 2010, 2011 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 50 matching lines @@
     GraphicsLayerUpdateSubtree,
 };
 
 // CompositedLayerMapping keeps track of how Layers of the layout tree correspond to
 // GraphicsLayers of the composited layer tree. Each instance of CompositedLayerMapping
 // manages a small cluster of GraphicsLayers and the references to which Layers
 // and paint phases contribute to each GraphicsLayer.
 //
 // Currently (Oct. 2013) there is one CompositedLayerMapping for each Layer,
 // but this is likely to evolve soon.
-class CORE_EXPORT CompositedLayerMapping final : public GraphicsLayerClient {
+class CORE_EXPORT CompositedLayerMapping final : public GraphicsLayerClient, public DisplayItemClient {

[pdr., 2015/12/05 21:39:19]

If the plan is to move invalidation bits and rects to DisplayItemClient, CLM
feels pretty weird having those. Should we be using the GraphicsLayer instead of
CLM as a client?

[Xianzhu, 2015/12/07 17:14:00]

Yes. Done.

Perhaps we can also have a CacheableDisplayItemClient for invalidation bits and
rects, so that non-cacheable display item clients don't need to care about these
methods. 

 
     WTF_MAKE_NONCOPYABLE(CompositedLayerMapping); USING_FAST_MALLOC(CompositedLayerMapping);
 public:
     explicit CompositedLayerMapping(PaintLayer&);
     ~CompositedLayerMapping() override;
 
     PaintLayer& owningLayer() const { return m_owningLayer; }
 
     bool updateGraphicsLayerConfiguration();
     void updateGraphicsLayerGeometry(const PaintLayer* compositingContainer, const PaintLayer* compositingStackingContext, Vector<PaintLayer*>& layersNeedingPaintInvalidation);
@@ skipping 38 matching lines @@
     GraphicsLayer* squashingLayer() const { return m_squashingLayer.get(); }
 
     void setSquashingContentsNeedDisplay();
     void setContentsNeedDisplay();
     // LayoutRect is in the coordinate space of the layer's layout object.
     void setContentsNeedDisplayInRect(const LayoutRect&, PaintInvalidationReason);
 
     // If |visualRect| is not nullptr, it contains all pixels that might be painted by the display item client,
     // in coordinate space of the layer's layout object.
     // |visualRect| can be nullptr if we know it's unchanged and PaintController has cached the previous value.
-    void invalidateDisplayItemClient(const DisplayItemClientWrapper&, PaintInvalidationReason, const LayoutRect* visualRect);
-    void invalidateDisplayItemClientOnScrollingContentsLayer(const DisplayItemClientWrapper&, PaintInvalidationReason, const LayoutRect* visualRect);
+    void invalidateDisplayItemClient(const DisplayItemClient&, PaintInvalidationReason, const LayoutRect* visualRect);
+    void invalidateDisplayItemClientOnScrollingContentsLayer(const DisplayItemClient&, PaintInvalidationReason, const LayoutRect* visualRect);
 
     // Notification from the layoutObject that its content changed.
     void contentChanged(ContentChangeType);
 
     LayoutRect compositedBounds() const { return m_compositedBounds; }
     IntRect pixelSnappedCompositedBounds() const;
 
     void positionOverflowControlsLayers();
 
     // Returns true if the assignment actually changed the assigned squashing layer.
@@ skipping 63 matching lines @@
     LayoutPoint squashingOffsetFromTransformedAncestor()
     {
         return m_squashingLayerOffsetFromTransformedAncestor;
     }
 
     // If there is a squashed layer painting into this CLM that is an ancestor of the given LayoutObject, return it. Otherwise return nullptr.
     const GraphicsLayerPaintInfo* containingSquashedLayer(const LayoutObject*, unsigned maxSquashedLayerIndex);
 
     void updateScrollingBlockSelection();
 
-    DisplayItemClient displayItemClient() const { return toDisplayItemClient(this); }
-    String debugName() const { return "CompositedLayerMapping for " + owningLayer().debugName(); }
+    String debugName() const override { return "CompositedLayerMapping for " + owningLayer().debugName(); }
 
 private:
     IntRect recomputeInterestRect(const GraphicsLayer*) const;
     static bool interestRectChangedEnoughToRepaint(const IntRect& previousInterestRect, const IntRect& newInterestRect, const IntSize& layerSize);
 
     static const GraphicsLayerPaintInfo* containingSquashedLayer(const LayoutObject*,  const Vector<GraphicsLayerPaintInfo>& layers, unsigned maxSquashedLayerIndex);
 
     // Helper methods to updateGraphicsLayerGeometry:
     void computeGraphicsLayerParentLocation(const PaintLayer* compositingContainer, const IntRect& ancestorCompositingBounds, IntPoint& graphicsLayerParentLocation);
     void updateSquashingLayerGeometry(const LayoutPoint& offsetFromCompositedAncestor, const IntPoint& graphicsLayerParentLocation, const PaintLayer& referenceLayer, Vector<GraphicsLayerPaintInfo>& layers, GraphicsLayer*, LayoutPoint* offsetFromTransformedAncestor, Vector<PaintLayer*>& layersNeedingPaintInvalidation);
@@ skipping 216 matching lines @@
 
     unsigned m_backgroundLayerPaintsFixedRootBackground : 1;
     unsigned m_scrollingContentsAreEmpty : 1;
 
     friend class CompositedLayerMappingTest;
 };
 
 } // namespace blink
 
 #endif // CompositedLayerMapping_h