[Sync] Plumb initial type set from engine to DTM.

[Sync] Plumb initial type set from engine to DTM.

This change is in preparation for moving the synchronous configure logic
out of SyncBackendRegistrar and into DataTypeManagerImpl.

BUG=663125
Committed: https://crrev.com/27ff5590e848a211fc06eb383b3ac954fc5e9901
Cr-Commit-Position: refs/heads/master@{#437119}

[maxbogue, 2016-12-06 20:28:10]

The CQ bit was checked by maxbogue@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-06 20:28:52]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[maxbogue, 2016-12-06 20:30:05]

maxbogue@chromium.org changed reviewers:
+ pavely@chromium.org

[maxbogue, 2016-12-06 20:30:06]

Pavel, PTAL. I think the changes in PSS are the only interesting ones; they're
kinda ugly but I'm not sure whether it's a step in the right direction or the
wrong one. I think it makes sense for the DTM to be created in
OnBackendInitialized() but figuring out the configure reason gets weirder.

[commit-bot: I haz the power, 2016-12-06 21:20:12]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-12-06 21:20:12]

Dry run: This issue passed the CQ dry run.

[pavely, 2016-12-08 00:06:34]

lgtm

[maxbogue, 2016-12-08 00:24:25]

The CQ bit was checked by maxbogue@chromium.org

[commit-bot: I haz the power, 2016-12-08 00:25:11]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-08 01:38:18]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1481156665771040,
"parent_rev": "304eec151b1cc3383117f4976471441874e67ea8", "commit_rev":
"35ac193d9f9f359ecc2e12d185133fbd0f09d13b"}

[commit-bot: I haz the power, 2016-12-08 01:39:10]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-12-08 01:44:20]

Description was changed from

==========
[Sync] Plumb initial type set from engine to DTM.

This change is in preparation for moving the synchronous configure logic
out of SyncBackendRegistrar and into DataTypeManagerImpl.

BUG=663125
==========

to

==========
[Sync] Plumb initial type set from engine to DTM.

This change is in preparation for moving the synchronous configure logic
out of SyncBackendRegistrar and into DataTypeManagerImpl.

BUG=663125

Committed: https://crrev.com/27ff5590e848a211fc06eb383b3ac954fc5e9901
Cr-Commit-Position: refs/heads/master@{#437119}
==========

[commit-bot: I haz the power, 2016-12-08 01:44:21]

Patchset 2 (id:??) landed as
https://crrev.com/27ff5590e848a211fc06eb383b3ac954fc5e9901
Cr-Commit-Position: refs/heads/master@{#437119}