Revert of Start moving ownership of SyncNotificationController to SyncController.

Revert of Start moving ownership of SyncNotificationController to SyncController. (patchset #3 id:40001 of https://codereview.chromium.org/889723002/)

Reason for revert:
Broke downstream builds

Original issue's description:
> Start moving ownership of SyncNotificationController to SyncController.
>
> GoogleServicesNotificationController is modified to work
> the way most other singleton classes work, so that it is
> not necessary to pass into the SyncNotificationController
> constructor (and thus, into SyncController in the future).
>
> SyncController gets a temporary setter method so that SNC
> can be constructed downstream and passed in until all its
> dependencies are upstream.
>
> BUG=428882
>
> Committed: https://crrev.com/deaa0fe6ca3e0428a85fc22b019819437d84120b
> Cr-Commit-Position: refs/heads/master@{#314515}

TBR=nyquist@chromium.org,maxbogue@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=428882
Committed: https://crrev.com/0d4fcfbcbc0fc0b06c454d4a8706262a007eabba
Cr-Commit-Position: refs/heads/master@{#314537}

[perezju, 2015-02-04 10:55:36]

Created Revert of Start moving ownership of SyncNotificationController to
SyncController.

[commit-bot: I haz the power, 2015-02-04 10:56:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/895373002/1

[commit-bot: I haz the power, 2015-02-04 10:57:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-04 10:59:13]

Patchset 1 (id:??) landed as
https://crrev.com/0d4fcfbcbc0fc0b06c454d4a8706262a007eabba
Cr-Commit-Position: refs/heads/master@{#314537}