Rebuild layout tree in flat tree order.

third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp

Index: third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp
diff --git a/third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp b/third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp
index 394bb2a334a381594ffe03ffe4559e235e8a900d..788db882618804cf93a6645389e8fd7fdeeafa24 100644
--- a/third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp
+++ b/third_party/WebKit/Source/core/dom/shadow/InsertionPoint.cpp
@@ -121,6 +121,14 @@ void InsertionPoint::DetachLayoutTree(const AttachContext& context) {
   HTMLElement::DetachLayoutTree(context);
 }
 
+void InsertionPoint::RebuildDistributedChildrenLayoutTrees() {
+  Text* next_text_sibling = nullptr;
+  // This loop traverses the nodes from right to left for the same reason as the
+  // one described in ContainerNode::RebuildChildrenLayoutTrees().
+  for (size_t i = distributed_nodes_.size(); i > 0; --i)
+    RebuildLayoutTreeForChild(distributed_nodes_.at(i - 1), next_text_sibling);
+}
+
 void InsertionPoint::WillRecalcStyle(StyleRecalcChange change) {
   StyleChangeType style_change_type = kNoStyleChange;