depot_tools: add .gitcookies support to gerrit_util
depot_tools: add .gitcookies support to gerrit_util

BUG=551403

Review URL: https://codereview.chromium.org/1419173011

git-svn-id: fd409f4bdeea2bb50a5d34bb4d4bfc2046a5a3dd@297450 0039d316-1c4b-4281-b951-d872f2087c98

disigma/depot_tools,duongbaoduy/gtools,duongbaoduy/gtools,aleonliao/depot_tools,CoherentLabs/depot_tools,CoherentLabs/depot_tools,aleonliao/depot_tools,disigma/depot_tools,primiano/depot_tools,primiano/depot_tools,azureplus/chromium_depot_tools,duanwujie/depot_tools,azureplus/chromium_depot_tools,primiano/depot_tools,duanwujie/depot_tools,hsharsha/depot_tools,disigma/depot_tools,azureplus/chromium_depot_tools,duanwujie/depot_tools,aleonliao/depot_tools,hsharsha/depot_tools,duongbaoduy/gtools,hsharsha/depot_tools