Add data usage tracking for sync service

Add data usage tracking for sync service

BUG=655749
Committed: https://crrev.com/261e942a33a7be65253c33398c1b91db36f396c4
Cr-Commit-Position: refs/heads/master@{#435708}

[Raj, 2016-12-01 00:55:48]

rajendrant@chromium.org changed reviewers:
+ zea@chromium.org

[Raj, 2016-12-01 00:55:49]

ptal

[Nicolas Zea, 2016-12-01 19:04:18]

lgtm

[Raj, 2016-12-01 19:25:33]

The CQ bit was checked by rajendrant@chromium.org

[commit-bot: I haz the power, 2016-12-01 19:26:07]

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, 2016-12-01 21:00:01]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480620333442830, "parent_rev":
"4211f7e330320920520798f6d2631af6e705f29f", "commit_rev":
"70b1079e7c20f796668a5bdff083db40741a47c2"}

[commit-bot: I haz the power, 2016-12-01 21:00:25]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-12-01 21:03:58]

Description was changed from

==========
Add data usage tracking for sync service

BUG=655749
==========

to

==========
Add data usage tracking for sync service

BUG=655749

Committed: https://crrev.com/261e942a33a7be65253c33398c1b91db36f396c4
Cr-Commit-Position: refs/heads/master@{#435708}
==========

[commit-bot: I haz the power, 2016-12-01 21:03:59]

Patchset 1 (id:??) landed as
https://crrev.com/261e942a33a7be65253c33398c1b91db36f396c4
Cr-Commit-Position: refs/heads/master@{#435708}