Add missing MappedHostResolver overrides

Save for remapping hosts according to the rules, MappedHostResolver
should be a transparent wrapper around the "real" resolver.  Thus, it
must forward all HostResolver methods to the real resolver.

Change-Id: I34deed523b3cb690d450599c89bfd7f2184e843d
Reviewed-on: https://chromium-review.googlesource.com/1209402
Commit-Queue: Wojciech Dzierżanowski <wdzierzanowski@opera.com>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589150}
2 files changed