[extensions][signin] Extensions use any accounts when Dice is enabled

Extensions were restricted to the primary (Sync) account. When Dice is
enabled, this restriction can be lifted, because Chrome can create
oauth tokens even when Sync is not enabled.

Bug: 852147
Change-Id: I0594500bcd950aaf74019817ea5a5e4b5bf7fa26
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1454896
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653133}
2 files changed