[Sync] Add support for identifying tabbed activites
Tabbed activites are different from non-tabbed activities in that they get
preserved on cold start start if no other tabbed activities are present,
as it's assumed they just haven't been loaded. Other activities, like
custom tabs, are not restored by sync.
This patch adds the plumbing for detecting if the activity is tabbed, and
persists that information within the sync window type. Windows are now
either tabbed, popup, or custom tabs.
BUG=
639009
Committed:
https://crrev.com/fb4ce10866412b0ecddb9e6b207fe643314f491f
Cr-Commit-Position: refs/heads/master@{#431163}