Implement the framework for a paint property hierarchy

third_party/WebKit/Source/core/paint/PaintLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 48 matching lines @@
 #include "wtf/Allocator.h"
 #include "wtf/OwnPtr.h"
 
 namespace blink {
 
 class FilterEffectBuilder;
 class FilterOperations;
 class HitTestRequest;
 class HitTestResult;
 class HitTestingTransformState;
+class ObjectPaintProperties;
 class PaintLayerCompositor;
 class CompositedLayerMapping;
 class ComputedStyle;
 class TransformationMatrix;
 
 enum IncludeSelfOrNot { IncludeSelf, ExcludeSelf };
 
 enum CompositingQueryMode {
     CompositingQueriesAreAllowed,
     CompositingQueriesAreOnlyAllowedInCertainDocumentLifecyclePhases
@@ skipping 482 matching lines @@
     bool needsRepaint() const { return m_needsRepaint; }
     void setNeedsRepaint();
     void clearNeedsRepaint() { m_needsRepaint = false; }
 
     IntSize previousScrollOffsetAccumulationForPainting() const { return m_previousScrollOffsetAccumulationForPainting; }
     void setPreviousScrollOffsetAccumulationForPainting(const IntSize& s) { m_previousScrollOffsetAccumulationForPainting = s; }
 
     // For subsequence display items.
     DisplayItemClient displayItemClient() const { return toDisplayItemClient(this); }
 
+    // Paint properties encode the hierarchical transform, clip, scroll, and
+    // effect information used for painting. Properties should only be changed
+    // during UpdatePaintProperties, and should only be used during Paint.
+    ObjectPaintProperties& mutablePaintProperties();
+    const ObjectPaintProperties* paintProperties() const;
+
 private:
     // Bounding box in the coordinates of this layer.
     LayoutRect logicalBoundingBox() const;
 
     bool hasOverflowControls() const;
 
     void dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
 
     // Returns true if the position changed.
     bool updateLayerPosition();
@@ skipping 164 matching lines @@
 
     OwnPtr<CompositedLayerMapping> m_compositedLayerMapping;
     OwnPtrWillBePersistent<PaintLayerScrollableArea> m_scrollableArea;
 
     CompositedLayerMapping* m_groupedMapping;
 
     PaintLayerClipper m_clipper; // FIXME: Lazily allocate?
     OwnPtr<PaintLayerStackingNode> m_stackingNode;
     OwnPtr<PaintLayerReflectionInfo> m_reflectionInfo;
 
+    // Lazily-allocated paint properties for m_layoutObject, stored here to
+    // reduce memory usage as PaintLayers are created for all paint property
+    // layout objects.
+    OwnPtr<ObjectPaintProperties> m_paintProperties;
+
     LayoutSize m_subpixelAccumulation; // The accumulated subpixel offset of a composited layer's composited bounds compared to absolute coordinates.
 
     IntSize m_previousScrollOffsetAccumulationForPainting;
 };
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLayerTree(const blink::PaintLayer*);
 void showLayerTree(const blink::LayoutObject*);
 #endif
 
 #endif // Layer_h