Remove ios/chrome from callback exceptions.

All the code under this directory has been converted to using modern callbacks.

Bug: 1007792
Change-Id: Ide911f55b785201c3327658a0b2c191392b6e649
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2521970


Auto-Submit: Renjie Tang <renjietang@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824810}