Element::recalcStyle() overly reattach()-es InsertionPoints.

Source/core/dom/NodeRenderingTraversal.cpp

Index: Source/core/dom/NodeRenderingTraversal.cpp
diff --git a/Source/core/dom/NodeRenderingTraversal.cpp b/Source/core/dom/NodeRenderingTraversal.cpp
index 1b23181f832898e94239b6e00a8f895c2815490b..97245cde99229c512e1335a216251350b64efabd 100644
--- a/Source/core/dom/NodeRenderingTraversal.cpp
+++ b/Source/core/dom/NodeRenderingTraversal.cpp
@@ -49,6 +49,9 @@ void ParentDetails::didTraverseShadowRoot(const ShadowRoot* root)
 
 ContainerNode* parentSlow(const Node* node, ParentDetails* details)
 {
+    if (ShadowRoot* root = node->containingShadowRoot())
+        ContentDistributor::ensureDistribution(root);
+
     ComposedShadowTreeWalker walker(node, ComposedShadowTreeWalker::CrossUpperBoundary, ComposedShadowTreeWalker::CanStartFromShadowBoundary);
     ContainerNode* found = toContainerNode(walker.traverseParent(walker.get(), details));
     return details->outOfComposition() ? 0 : found;