Refactor LocalBorderBoxProperties to use PropertyTreeState

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ObjectPaintProperties_h
 #define ObjectPaintProperties_h
 
 #include "core/CoreExport.h"
 #include "platform/geometry/LayoutPoint.h"
 #include "platform/graphics/paint/ClipPaintPropertyNode.h"
@@ skipping 20 matching lines @@
     }
     const TransformPaintPropertyNode* transform;
     const ClipPaintPropertyNode* clip;
     const EffectPaintPropertyNode* effect;
     const ScrollPaintPropertyNode* scroll;
 };
 
 // This class stores property tree related information associated with a LayoutObject.
 // Currently there are two groups of information:
 // 1. The set of property nodes created locally by this LayoutObject.
-// 2. [Optional] A suite of property nodes (PaintChunkProperties) and paint offset
-//    that can be used to paint the border box of this LayoutObject.
+// 2. [Optional] A suite of property nodes (PropertyTreeState) and paint offset

[chrishtr, 2016/09/26 17:09:51]

Remove the parenthetical, not accurate at this point.

+//    that can be used to paint the border box of this LayoutObject. These nodes
+//    may be created locally by the LayoutObject, or may be in inherited.
 class CORE_EXPORT ObjectPaintProperties {
     WTF_MAKE_NONCOPYABLE(ObjectPaintProperties);
     USING_FAST_MALLOC(ObjectPaintProperties);
 public:
     struct LocalBorderBoxProperties;
 
     static std::unique_ptr<ObjectPaintProperties> create()
     {
         return wrapUnique(new ObjectPaintProperties());
     }
@@ skipping 27 matching lines @@
 
     // The hierarchy of the clip subtree created by a LayoutObject is as follows:
     // [ css clip ]
     // [ css clip fixed position]
     // |
     // +--- [ overflow clip ]
     const ClipPaintPropertyNode* cssClip() const { return m_cssClip.get(); }
     const ClipPaintPropertyNode* cssClipFixedPosition() const { return m_cssClipFixedPosition.get(); }
     const ClipPaintPropertyNode* overflowClip() const { return m_overflowClip.get(); }
 
-    // This is a complete set of property nodes that should be used as a starting point to paint
-    // this layout object. It is needed becauase some property inherits from the containing block,
-    // not painting parent, thus can't be derived in O(1) during paint walk.
-    // Note: If this layout object has transform or stacking-context effects, those are already
-    // baked into in the context here. However for properties that affects only children,
-    // for example, perspective and overflow clip, those should be applied by the painter
-    // at the right painting step.
-    // TODO(pdr): Refactor this to use PropertyTreeState.
+    // This is a complete state that should be used as a starting point to paint this object. It is
+    // needed because some properties inherit from the containing block, not painting parent, and
+    // can't be derived in O(1) during paint walk.
+    // If this layout object has transform or stacking-context effects, those are already baked into
+    // in the context here. Properties that affect only children, for example perspective and
+    // overflow clip, should be applied by the painter at the right painting step.
     struct LocalBorderBoxProperties {
+        LocalBorderBoxProperties(LayoutPoint offset, PropertyTreeState treeState)
+            : paintOffset(offset), propertyTreeState(treeState) { }
         LayoutPoint paintOffset;
-        GeometryPropertyTreeState geometryPropertyTreeState;
-        const ScrollPaintPropertyNode* scroll;
+        PropertyTreeState propertyTreeState;
     };
     const LocalBorderBoxProperties* localBorderBoxProperties() const { return m_localBorderBoxProperties.get(); }
-    // ContentsProperties is the GeometryPropertyTreeState that is the same as in
-    // localBorderBoxProperties, except that it is inside any clips and scrolls caused by this
-    // object. This GeometryPropertyTreeState is suitable as the destination for paint invalidation.
-    void getContentsProperties(GeometryPropertyTreeState&) const;
+    // ContentsProperties returns the same property tree state in localBorderBoxProperties
+    // but modified to be inside any clips and scrolls caused by this object. This
+    // GeometryPropertyTreeState is suitable as the destination for paint invalidation.
+    GeometryPropertyTreeState getContentsProperties() const;

[szager1, 2016/09/24 01:30:17]

Why do we need both PropertyTreeState and GeometryPropertyTreeState?

 
     void clearPaintOffsetTranslation() { m_paintOffsetTranslation = nullptr; }
     void clearTransform() { m_transform = nullptr; }
     void clearEffect() { m_effect = nullptr; }
     void clearCssClip() { m_cssClip = nullptr; }
     void clearCssClipFixedPosition() { m_cssClipFixedPosition = nullptr; }
     void clearOverflowClip() { m_overflowClip = nullptr; }
     void clearPerspective() { m_perspective = nullptr; }
     void clearSvgLocalToBorderBoxTransform() { m_svgLocalToBorderBoxTransform = nullptr; }
     void clearScrollTranslation() { m_scrollTranslation = nullptr; }
@@ skipping 47 matching lines @@
     RefPtr<TransformPaintPropertyNode> m_scrollTranslation;
     RefPtr<TransformPaintPropertyNode> m_scrollbarPaintOffset;
     RefPtr<ScrollPaintPropertyNode> m_scroll;
 
     std::unique_ptr<LocalBorderBoxProperties> m_localBorderBoxProperties;
 };
 
 } // namespace blink
 
 #endif // ObjectPaintProperties_h