Re: [service-workers-tests] [service-workers] Avoid race condition in test (#4879)

# Firefox (nightly channel) #
Testing web-platform-tests at revision 92e35a213d0ad08662ba0a4eea5246f4aff170f5
Using browser at version BuildID 20170123125947; SourceStamp 36486fdc3813ef7943ae5b07b4128866d1938a6c
Starting 10 test iterations
All results were stable
## All results ##
<details>
<summary>1 test ran</summary>
<details>
<summary><a href="https://w3c-test.org/submissions/4879/service-workers/service-worker/request-end-to-end.https.html">/service-workers/service-worker/request-end-to-end.https.html</a></summary>


|        Subtest        | Results |
|-----------------------|---------|
|                       | OK      |
| `Request: end-to-end` | PASS    |

</details>
</details>

View on GitHub: https://github.com/w3c/web-platform-tests/pull/4879#issuecomment-280192075

Received on Thursday, 16 February 2017 00:45:46 UTC