Revert of [GCM] Adding periodic checkin controlled by G-services settings

Revert of [GCM] Adding periodic checkin controlled by G-services settings (https://codereview.chromium.org/215363007/)

Reason for revert:
http://build.chromium.org/p/chromium.mac/builders/Mac10.7%20Tests%20%282%29/builds/25118

These tests fail: 

gcm_unit_tests:
GServicesSettingsDifferentDigest
GServicesSettingsSameDigest
PeriodicCheckin

They should be in the cq, I believe scottmg has filed a bug to put them in the CQ list.

Original issue's description:
> Adding periodic checkin controlled by G-services settings
> 
> * extracting CheckinRequest::RequestInfo to better manage checkin parameters
> * adding G-services settings digest to RequestInfo of the checkin (will be sent with checkin request)
> * extracting G-services settings from checkin response
> * storing and loading of the G-services settings in GCM Store
> 
> BUG=359254
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=261912

TBR=zea@chromium.org,jianli@chromium.org,fgorski@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=359254
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=261916

[tommycli, 2014-04-04 23:47:25]

Created Revert of [GCM] Adding periodic checkin controlled by G-services
settings

[commit-bot: I haz the power, 2014-04-04 23:48:01]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/tommycli@chromium.org/226893002/1

[commit-bot: I haz the power, 2014-04-04 23:49:39]

Change committed as 261916