Gerrit git cl land: abort if not uploaded.
Gerrit git cl land: abort if not uploaded.

R=agable@chromium.org
BUG=642759,609225

Review-Url: https://codereview.chromium.org/2317253003

CoherentLabs/depot_tools,primiano/depot_tools,CoherentLabs/depot_tools,primiano/depot_tools,primiano/depot_tools