Slimming Paint phase 2 compositing algorithm plumbing & skeleton display list API.

Source/platform/graphics/GraphicsLayer.h

Index: Source/platform/graphics/GraphicsLayer.h
diff --git a/Source/platform/graphics/GraphicsLayer.h b/Source/platform/graphics/GraphicsLayer.h
index a04c02f2a17aeea742e716c640936f6442596ca2..03548f59139b4dd159006cfe666e8b2242c16b42 100644
--- a/Source/platform/graphics/GraphicsLayer.h
+++ b/Source/platform/graphics/GraphicsLayer.h
@@ -39,6 +39,9 @@
 #include "platform/graphics/PaintInvalidationReason.h"
 #include "platform/graphics/filters/FilterOperations.h"
 #include "platform/graphics/paint/DisplayItemClient.h"
+#include "platform/graphics/paint/DisplayItemList.h"
+#include "platform/graphics/paint/DisplayItemTransformTree.h"
+#include "platform/graphics/paint/DisplayList.h"
 #include "platform/transforms/TransformationMatrix.h"
 #include "public/platform/WebCompositorAnimationDelegate.h"
 #include "public/platform/WebContentLayer.h"
@@ -148,6 +151,12 @@ public:
     const FloatPoint3D& transformOrigin() const { return m_transformOrigin; }
     void setTransformOrigin(const FloatPoint3D&);
 
+    void setTransformTree(PassOwnPtr<const DisplayItemTransformTree>);
+    const DisplayItemTransformTree* transformTree() const override;
+
+    const DisplayList* displayList() const override;
+    void setDisplayList(PassOwnPtr<DisplayList>);
+
     // The size of the layer.
     const FloatSize& size() const { return m_size; }
     void setSize(const FloatSize&);
@@ -249,6 +258,7 @@ public:
 
     // GraphicsContextPainter implementation.
     void paint(GraphicsContext&, const IntRect& clip) override;
+    void paint(GraphicsContext&);
 
     // WebCompositorAnimationDelegate implementation.
     void notifyAnimationStarted(double monotonicTime, int group) override;
@@ -368,6 +378,8 @@ private:
     int m_3dRenderingContext;
 
     OwnPtr<DisplayItemList> m_displayItemList;
+    OwnPtr<const DisplayItemTransformTree> m_transformTree;
+    OwnPtr<const DisplayList> m_displayList;
 };
 
 } // namespace blink