Isolation of subtrees of stacking contexts and out-of-flow positioned objects

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

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
index a1d60a1e2f09a74a8cf6b9e4d306470424921efe..8bc1a2dc59279dbfca125f83391f480fbdeff05c 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
@@ -68,49 +68,61 @@ public:
     void buildTreeNodes(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
 private:
+    // Result of computeXXX() functions to indicate which type of paint property node is needed for the object.
+    enum PaintPropertyNodeType {
+        NoNode,
+        NormalNode,
+        // See isPaintPropertyIsolationBoundary() in PaintPropertyTreeBuilder.cpp.
+        IsolationNode,
+    };
+
     // Common logic to update a paint property. It tries to reuse the existing paint property node of
     // the object if the value is not changed. Returns the existing or newly created paint property node,
     // or nullptr if no paint property node is needed.
     // It requires a ComputeProperty function which computes the paint property node value if needed and
-    // returns true, or returns false if no paint property node value is needed.
+    // returns PaintPropertyNodeType.
     template <
         typename PropertyNode,
         PropertyNode* (ObjectPaintProperties::*Getter)() const,
         void (ObjectPaintProperties::*Setter)(PassRefPtr<PropertyNode>),
-        bool (*ComputeProperty)(const LayoutObject&, PaintPropertyTreeBuilderContext&, typename PropertyNode::Value&)>
+        PaintPropertyNodeType (*ComputeProperty)(const LayoutObject&, PaintPropertyTreeBuilderContext&, typename PropertyNode::Value&)>
     static PropertyNode* updateObjectPaintProperty(const LayoutObject&, PaintPropertyTreeBuilderContext&, PropertyNode*& contextProperty);
 
-    static bool computePaintOffsetTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computePaintOffsetTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
     static void updatePaintOffsetTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computeTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
     static void updateTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computeEffect(const LayoutObject&, PaintPropertyTreeBuilderContext&, EffectPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeEffect(const LayoutObject&, PaintPropertyTreeBuilderContext&, EffectPaintPropertyNode::Value&);
     static void updateEffect(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computeCssClip(const LayoutObject&, PaintPropertyTreeBuilderContext&, ClipPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeCssClip(const LayoutObject&, PaintPropertyTreeBuilderContext&, ClipPaintPropertyNode::Value&);
     static void updateCssClip(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
     static void updateLocalBorderBoxContext(const LayoutObject&, const PaintPropertyTreeBuilderContext&);
 
-    static bool computeScrollbarPaintOffset(const LayoutObject&, const PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeScrollbarPaintOffset(const LayoutObject&, const PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
     static void updateScrollbarPaintOffset(const LayoutObject&, const PaintPropertyTreeBuilderContext&);
 
-    static bool computeOverflowClip(const LayoutObject&, PaintPropertyTreeBuilderContext&, ClipPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeOverflowClip(const LayoutObject&, PaintPropertyTreeBuilderContext&, ClipPaintPropertyNode::Value&);
     static void updateOverflowClip(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computePerspective(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computePerspective(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
     static void updatePerspective(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computeSvgLocalToBorderBoxTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeSvgLocalToBorderBoxTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
     static void updateSvgLocalToBorderBoxTransform(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computeScrollTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeScrollTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&, TransformPaintPropertyNode::Value&);
     static void updateScrollTranslation(const LayoutObject&, PaintPropertyTreeBuilderContext&);
 
-    static bool computeOutOfFlowContext(const LayoutObject&, PaintPropertyTreeBuilderContext&, ClipPaintPropertyNode::Value&);
+    static PaintPropertyNodeType computeOutOfFlowContext(const LayoutObject&, PaintPropertyTreeBuilderContext&, ClipPaintPropertyNode::Value&);
     static void updateOutOfFlowContext(const LayoutObject&, PaintPropertyTreeBuilderContext&);
+
+#if DCHECK_IS_ON()
+    static void checkPropertyIsolationBoundaryForStackingContext(const LayoutObject&);
+#endif
 };
 
 } // namespace blink