[ObjC ARC] Converts ios/web:web to ARC.

Automatically generated ARCMigrate commit
Notable issues:None
BUG=624363
TEST=None

Change-Id: Ia41029159b54a20c08af66b313fa53a3138184e7
Reviewed-on: https://chromium-review.googlesource.com/570438
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Reviewed-by: Stepan Khapugin <stkhapugin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#495924}
11 files changed