Move BaseFetchContext::GetAddressSpace to FetchClientSettingsObject

"Client's address space" is defined as [1], so it's good to have the
property in FetchClientSettingsObject.

1: https://wicg.github.io/cors-rfc1918/#address-space

Bug: 914739
Change-Id: I81c0fd1c07af86a3a1c73624620d121a28475163
Reviewed-on: https://chromium-review.googlesource.com/c/1424685
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#627294}
16 files changed