Currently gerrit-trigger happens when the code is submitted for review. This automatically triggers a build. There are use cases where it may not be desirable to trigger the build until after at least one person has +1 or set a custom label to a +1 value (i.e. Initial Security Review Completed: +1). This would then allow a person to take a quick look at something, and then let the workflow build the change after a cursory glance at the code.

The rest of the gerrit-trigger process could then flow through (i.e. set verified, or set the custom label.).