Disallow requesting non-redirect keepalive request when detached

This is needed to be aligned with a DCHECK in
FrameFetchContext::CreateURLLoader.

Bug: 695939
Change-Id: I90c92c1b33fbe15d11ac5cf5907d841d853b5780
Reviewed-on: https://chromium-review.googlesource.com/605152
Reviewed-by: Takeshi Yoshino <tyoshino@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#494339}
2 files changed