Add account consistency flag for Desktop Identity Consistency.
This CL changes the account consistency flag to allow 2 options (Mirror
and Dice).
As Mirror is still an experimental feature that never launched on Desktop,
this CL simply removes the switch used to enable Mirror ("--enable-account-consistency")
and replaces it with ("--account-consistency") with 2 possible values ("mirror"
or "dice"). This avoid issues on startup when for users that have turned on Mirror
in chrome://flags.
TBR=pkasting,scottbyer,yhirano
BUG=728651
Review-Url: https://codereview.chromium.org/2916113002
Cr-Commit-Position: refs/heads/master@{#476673}
22 files changed
