Stop passing WebURLRequest to error page callbacks

There will be no WebURLRequest to pass once we stop (ab)using
WebURLLoader for navigations. See bug for details.

We only use a handfull of request's properties which we
currently pass directly.

Bug: 855189
TBR: content API change
Change-Id: I77ee2986df935753854dcebc1a4c7070c3c8a83d
Reviewed-on: https://chromium-review.googlesource.com/c/1385344
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618063}
11 files changed