Navigation: Move response_headers_for_testing to NavigationRequest.

This includes moving the checks in GetResponseHeaders from
NavigationHandleImpl to NavigationRequest.

Bug: 916537
Change-Id: I3e2c1bae2887d0b024ac3df6817b4bde40cfcb86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1729254
Reviewed-by: Lowell Manners <lowell@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Commit-Queue: Mohamed Abdelhalim <zetamoo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#683529}
8 files changed