Remove unused IsConnectedToDocument().

Change-Id: I07952c200bc86cfb262353ac1ad06adb631e53a6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1731941Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683550}

third_party/blink/renderer/core/css/style_traversal_root.cc

@@ -56,16 +56,4 @@ void StyleTraversalRoot::ChildrenRemoved(ContainerNode& parent) {
   Clear();
 }
 
-#if DCHECK_IS_ON()
-bool StyleTraversalRoot::IsConnectedToDocument(Node& node) const {
-  if (node.IsDocumentNode())
-    return true;
-  for (Node& parent : NodeTraversal::AncestorsOf(node)) {
-    if (parent.IsDocumentNode())
-      return true;
-  }
-  return false;
-}
-#endif  // DCHECK_IS_ON()
-
 }  // namespace blink

third_party/blink/renderer/core/css/style_traversal_root.h

@@ -71,10 +71,6 @@ class CORE_EXPORT StyleTraversalRoot {
  private:
   friend class StyleTraversalRootTestImpl;
 
-#if DCHECK_IS_ON()
-  bool IsConnectedToDocument(Node&) const;
-#endif  // DCHECK_IS_ON()
-
   // The current root for dirty nodes.
   Member<Node> root_node_;