The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/762993055a75a8f62232e5454f16b566a2de7e3c

commit 762993055a75a8f62232e5454f16b566a2de7e3c
Author: Nico Weber <thakis@chromium.org>
Date: Thu Feb 01 20:36:45 2018

Download ciopfs from a hook in win/cross builds.

Useful for people where the linux installation doesn't provide it by
default, and for bots.

I copied the system ciopfs binary on my ubuntu trusty box to build/ciopfs
and ran:

  upload_to_google_storage.py -b chromium-browser-clang/ciopfs build/ciopfs

Bug: 808098
Change-Id: Ia6dd7548a5a5761898506f6bbe50625c33151988
Reviewed-on: https://chromium-review.googlesource.com/897890
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533804}
[modify] https://crrev.com/762993055a75a8f62232e5454f16b566a2de7e3c/DEPS
[modify] https://crrev.com/762993055a75a8f62232e5454f16b566a2de7e3c/build/.gitignore
[add] https://crrev.com/762993055a75a8f62232e5454f16b566a2de7e3c/build/ciopfs.sha1
[modify] https://crrev.com/762993055a75a8f62232e5454f16b566a2de7e3c/build/vs_toolchain.py