Instead of checking if changes found from a Depends-On line are merged,
check if they are open. This ignores abandoned changes when building the
list of dependent changes.
In the event that change I0000 depends-on change-id I1234 and change-id
I1234 matches multiple changes, one of which is abandoned, then change
I0000 will never enter the gate as it waits indefinitely for the abandoned
I1234 to become eligible for the gate.
Change-Id: Ia6ae7b1da13fa2bcf6fc08fac49563e7ac960a84
773651ad7b