Revert of [ObjC ARC] Reland of Converts ios/chrome/browser/ui/autofill:autofill to ARC. (patchset #3 id:40001 of https://codereview.chromium.org/2555673003/ )

Reason for revert:
Non-ARC files that include autofill_client_ios.h "cannot create __weak reference in file using manual reference counting".

Original issue's description:
> [ObjC ARC] Reland of Converts ios/chrome/browser/ui/autofill:autofill to ARC.
>
> Automatically generated ARCMigrate commit
> Notable issues:None
> BUG=624363
> TEST=None
> Originally landed as http://crrev.com/2513003002#ps1
>
> Committed: https://crrev.com/302d816fa77d64bd662c13e64e5a71352b728cfc
> Cr-Commit-Position: refs/heads/master@{#436645}

TBR=sdefresne@chromium.org,stkhapugin@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=624363

Review-Url: https://codereview.chromium.org/2560453003
Cr-Commit-Position: refs/heads/master@{#436690}
4 files changed