Add WPT to verify that 1XX responses are used to provide responseStart timing

Verifies that the UA sets responseStart to the time that an
initial 1XX response was received by returning {100, delay, 200} and
testing that the delay is not included in responseStart.

Bug: 568024
Change-Id: I7295e6478a95abe1b6154ddf1feab764f596a5ec
Reviewed-on: https://chromium-review.googlesource.com/c/1372359
Reviewed-by: Yoav Weiss <yoavweiss@chromium.org>
Commit-Queue: Yoav Weiss <yoavweiss@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615853}
2 files changed