Implement closed shadow adjustment for Element.offsetParent

third_party/WebKit/Source/core/dom/Node.cpp

Index: third_party/WebKit/Source/core/dom/Node.cpp
diff --git a/third_party/WebKit/Source/core/dom/Node.cpp b/third_party/WebKit/Source/core/dom/Node.cpp
index c0853351774bffbdfa5051e2dc6152fc5c16f15d..a68c03f8055a27d7c726ac51f6517caa08c9396c 100644
--- a/third_party/WebKit/Source/core/dom/Node.cpp
+++ b/third_party/WebKit/Source/core/dom/Node.cpp
@@ -636,6 +636,25 @@ Node& Node::shadowIncludingRoot() const
     return *root;
 }
 
+bool Node::isUnclosedNodeOf(const Node& other) const
+{
+    if (!isInShadowTree() || treeScope() == other.treeScope())
+        return true;
+
+    const TreeScope* scope = &treeScope();
+    for (; scope->parentTreeScope(); scope = scope->parentTreeScope()) {
+        const ContainerNode& root = scope->rootNode();
+        if (root.isShadowRoot() && !toShadowRoot(root).isOpenOrV0())
+            break;
+    }
+
+    for (TreeScope* otherScope = &other.treeScope(); otherScope; otherScope = otherScope->parentTreeScope()) {
+        if (otherScope == scope)
+            return true;
+    }
+    return false;
+}
+
 bool Node::needsDistributionRecalc() const
 {
     return shadowIncludingRoot().childNeedsDistributionRecalc();