Move variable to util (components/autofill/)

When building using jumbo, files get merged and
variables with the same name may
end up in the same namespace and conflict.

This happens for the constant kLocalGuidSize in autofill/core/browser.
The variable is moved to a util file in
common.

Bug: 869381
Change-Id: I038ef40acd5617f9d9d1e18c81a2fcce55cab8eb
Reviewed-on: https://chromium-review.googlesource.com/1158544
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Commit-Queue: Oscar Johansson <oscarj@opera.com>
Cr-Commit-Position: refs/heads/master@{#580142}
3 files changed