Preliminary paint property walk implementation for SPv2

third_party/WebKit/Source/core/layout/LayoutObject.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 42 matching lines @@
 #include "platform/transforms/TransformationMatrix.h"
 
 namespace blink {
 
 class AffineTransform;
 class Cursor;
 class Document;
 class HitTestLocation;
 class HitTestResult;
 class InlineBox;
-class PseudoStyleRequest;
 class LayoutBoxModelObject;
 class LayoutBlock;
 class LayoutFlowThread;
 class LayoutGeometryMap;
-class PaintLayer;
 class LayoutMultiColumnSpannerPlaceholder;
 class LayoutView;
+class ObjectPaintProperties;
+class PaintLayer;
+class PseudoStyleRequest;
 class TransformState;
 
 struct PaintInfo;
 
 enum CursorDirective {
     SetCursorBasedOnStyle,
     SetCursor,
     DoNotSetCursor
 };
 
@@ skipping 265 matching lines @@
     // TODO(jchaffraix): |newChild| cannot be nullptr and should be a reference.
     virtual void addChild(LayoutObject* newChild, LayoutObject* beforeChild = nullptr);
     virtual void addChildIgnoringContinuation(LayoutObject* newChild, LayoutObject* beforeChild = nullptr) { return addChild(newChild, beforeChild); }
     virtual void removeChild(LayoutObject*);
     virtual bool createsAnonymousWrapper() const { return false; }
     //////////////////////////////////////////
 
     // Sets the parent of this object but doesn't add it as a child of the parent.
     void setDangerousOneWayParent(LayoutObject*);
 
+    // For SPv2 only. These are implemented as a global hash map temporarily,

[pdr., 2015/10/20 22:02:30]

This is useful but more of an implementation detail. Can you move this comment
to LayoutObject.cpp above the ObjectPaintPropertiesMap typedef?

For readers that hit this, lets use something like the following comment here:
// 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.

[trchen, 2015/10/21 06:16:19]

Done.

+    // to avoid memory regression during the transition towards SPv2.
+    ObjectPaintProperties* objectPaintProperties() const;
+    ObjectPaintProperties& ensureObjectPaintProperties();
+    void clearObjectPaintProperties();
+
 private:
     //////////////////////////////////////////
     // Helper functions. Dangerous to use!
     void setPreviousSibling(LayoutObject* previous) { m_previous = previous; }
     void setNextSibling(LayoutObject* next) { m_next = next; }
     void setParent(LayoutObject* parent)
     {
         m_parent = parent;
 
         // Only update if our flow thread state is different from our new parent and if we're not a LayoutFlowThread.
@@ skipping 1635 matching lines @@
 void showTree(const blink::LayoutObject*);
 void showLineTree(const blink::LayoutObject*);
 void showLayoutTree(const blink::LayoutObject* object1);
 // We don't make object2 an optional parameter so that showLayoutTree
 // can be called from gdb easily.
 void showLayoutTree(const blink::LayoutObject* object1, const blink::LayoutObject* object2);
 
 #endif
 
 #endif // LayoutObject_h