Test for http://src.chromium.org/viewvc/blink?view=revision&revision=158550

This was promised as a followup to the crash fix.

BUG=301840

Review URL: https://codereview.chromium.org/25612002

git-svn-id: svn://svn.chromium.org/blink/trunk@158673 bbb929c8-8fbe-4397-9dbb-9b2b20218538