selectors/pseudo-class-defined.html correctly tests it by assuming that for createElement, createElementNS should behave the same for documents with or without browsing contexts.

Patch up at https://codereview.chromium.org/2313853002

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/2bcdfdc0925a30a682bc42d89d2f044de99a35a3

commit 2bcdfdc0925a30a682bc42d89d2f044de99a35a3
Author: davaajav <davaajav@google.com>
Date: Tue Sep 06 06:00:22 2016

CustomElements: tests in a document without browsing context

Custom elements in a document without a browsing context
should behave as follows:
1. element in a document without browsing context should not
   be upgraded
2. a "defined" custom element should not be created in a
  document without browsing context
3. an already defined element should remain defined after being
   inserted into a document without browsing context

BUG= 643053 

Review-Url: https://codereview.chromium.org/2313853002
Cr-Commit-Position: refs/heads/master@{#416591}

[add] https://crrev.com/2bcdfdc0925a30a682bc42d89d2f044de99a35a3/third_party/WebKit/LayoutTests/custom-elements/spec/doc-without-browsing-context.html

Previously, creating a custom element inside a document without browsing context would have left it "uncustomized", since previously in the step 7.3 element`s state is changed to "undefined" only when the document had a browsing context 

What's the status of this?

I think we can mark it as closed.