Revert 227100 "Track active references in ShillClientHelper (Tak..."

> Track active references in ShillClientHelper (Take 2)
> To prevent Shill Service DBus ObjectProxy instances from accumulating,
> remove them when the service becomes inactive.
> 
> Original CL: https://codereview.chromium.org/23658053/
> 
> BUG=223483
> TBR=hashimoto@chromium.org
> 
> Review URL: https://codereview.chromium.org/24558004

Failure:
http://build.chromium.org/p/chromium.memory/builders/Chromium%20OS%20%28amd64%29%20ASAN/builds/6931

TBR=stevenjb@chromium.org

Review URL: https://codereview.chromium.org/26075002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227139 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 227139