[Sync] Remove the last datatype-specific deps from sync_driver.

The ref-counted dependencies being injected by SyncClient are now
injected directly into the DTC's via the components factory.

BUG=543199
TBR=sdefresne

Review URL: https://codereview.chromium.org/1460723004

Cr-Commit-Position: refs/heads/master@{#364465}
24 files changed