Refactor LocalBorderBoxProperties to use PropertyTreeState

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

Index: third_party/WebKit/Source/core/paint/ObjectPaintProperties.h
diff --git a/third_party/WebKit/Source/core/paint/ObjectPaintProperties.h b/third_party/WebKit/Source/core/paint/ObjectPaintProperties.h
index 0e47c7782c4516f1107ac74f67890ad6a2fd1bec..e11e21431d2b44fe33c0bd0bcda6b98fdc95b4c9 100644
--- a/third_party/WebKit/Source/core/paint/ObjectPaintProperties.h
+++ b/third_party/WebKit/Source/core/paint/ObjectPaintProperties.h
@@ -38,8 +38,9 @@ struct PropertyTreeState {
 // 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);
@@ -87,24 +88,23 @@ public:
     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; }