GitLab

Adds a OTRProfileID::CreateUnique to create a unique OffTheRecrord
profile id with the given prefix.

Bug: 1033903
Change-Id: Iaa6408a17d72521b8c22feec82843ad4081abece
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2145875Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758766}