Revert 245447 "[GCM] Introduce GCMClientFactory to create GCMCli..."
This CL caused massive UAF/invalid free reports on the Valgrind bot

BUG=336360

> [GCM] Introduce GCMClientFactory to create GCMClient for GCMProfileService
> 
> We used to call GCMClient::Get() to get the single instance. This did not
> work when we need to pass some initialization data from browser to it.
> GCMClientFactory is introduced such that GCMClient instance can be
> created, initialized and used in GCMProfileService::IOWorker.
> 
> BUG=284553
> TEST=existing tests
> 
> Review URL: https://codereview.chromium.org/135903005

TBR=jianli@chromium.org

Review URL: https://codereview.chromium.org/134083006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246013 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246013