Revert of Send GCM id to DMServer

Revert of Send GCM id to DMServer (patchset #10 id:180001 of https://codereview.chromium.org/1258313002/ )

Reason for revert:
protobuf change on server side.

Original issue's description:
> Send GCM id to DMServer
>
> This CL add a device management request to send GCM id after registration to
> the server, so that server can maintain a mapping between GCM id and DM token.
>
> BUG=517466
>
> Committed: https://crrev.com/92960c61ee75a5323fc954b9819acca5b684d2aa
> Cr-Commit-Position: refs/heads/master@{#342364}

TBR=jinzhang@chromium.org,atwilson@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=517466
Committed: https://crrev.com/e884c3ab04a7cb1901660f45dfba1c4223bbfa8d
Cr-Commit-Position: refs/heads/master@{#342434}

[binjin, 2015-08-07 20:44:00]

Created Revert of Send GCM id to DMServer

[commit-bot: I haz the power, 2015-08-07 20:44:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1276853003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1276853003/1

[commit-bot: I haz the power, 2015-08-07 20:45:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-07 20:46:02]

Patchset 1 (id:??) landed as
https://crrev.com/e884c3ab04a7cb1901660f45dfba1c4223bbfa8d
Cr-Commit-Position: refs/heads/master@{#342434}