suppress uninit error at net::ProxyScriptDecider::DoLoop
TBR=ellyjones@chromium.org
BUG=329339
TEST=waterfall

Review URL: https://codereview.chromium.org/100643005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241416 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241416