NetS13nServiceWorker: Disable irrelevant test for MimeSniffingResourceHandler.

The test was written to test an internal quirk of
MimeSniffingResourceHandler, which isn't used with Network Service, and
service worker won't support MIME sniffing for now.

Also the quirk, OnStartLoadingResponseBody() called before OnReceiveResponse(),
seems to violate the contract in url_loader.mojom anyway.

Bug: 715640, 771118
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_mojo
Change-Id: If9671b3ad0756157064b577693fbea9a520460f6
Reviewed-on: https://chromium-review.googlesource.com/1095061
Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566270}
2 files changed