Convert PacFileDecider to new HostResolver API

Bug: 922699
Change-Id: I5ce40c35e3711f90979cd2ad38ad8764c7a86def
Reviewed-on: https://chromium-review.googlesource.com/c/1419137
Auto-Submit: Eric Orth <ericorth@chromium.org>
Commit-Queue: Asanka Herath <asanka@chromium.org>
Reviewed-by: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#623991}
2 files changed