Implement git cl upload --dry-run or --use-commit-queue for Gerrit.
Implement git cl upload --dry-run or --use-commit-queue for Gerrit.

Previously, it only worked for Rietveld.

BUG=622828
R=emso@chromium.org,machenbach@chromium.org

Review-Url: https://codereview.chromium.org/2117183004

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