Merge 253787 "[GCM] Make sure GCM checkout logic is invoked when..."

Merge 253787 "[GCM] Make sure GCM checkout logic is invoked when..."

> [GCM] Make sure GCM checkout logic is invoked when the profile is signed out
> 
> We now always create GCMProfileService that listens to profile
> notifications such that GCM checkout logic could be invoked when the
> profile is signed out.
> 
> We now move the GCM check-in logic from GCMClient::Initialize to GCMClient::CheckIn.
> 
> BUG=344031
> TEST=new tests added and existing tests updated
> 
> Review URL: https://codereview.chromium.org/165993005

TBR=jianli@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=255193

[jianli, 2014-03-06 01:11:18]

Committed patchset #2 manually as r255193.