service worker: WPT: Add test for XHR responseURL.

Bug: 915126
Change-Id: I2a81213e15a31c7d59ab9138a662b9f8d0a28ffe
Reviewed-on: https://chromium-review.googlesource.com/c/1414556
Reviewed-by: Ben Kelly <wanderview@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623418}
3 files changed