Add support for abandoning a dead change

Add the ability to abandon a change.  When the abandon button is
clicked, a dialog will pop up for the user to enter an abandon
message.  This message will be added as a comment to the change
and an email will be sent to all reviewers of the change.

Bug: GERRIT-41
Signed-off-by: Brad Larson <>
Signed-off-by: Shawn O. Pearce <>
11 files changed