Merge "Fix race in removeSyncBarrier that would cause a missing wakeup" into main

        boolean removed;

        final MatchBarrierToken matchBarrierToken = new MatchBarrierToken(token);

        // Retain the first element to see if we are currently stuck on a barrier.

        final Message m = first(mPriorityQueue);

        removed = findOrRemoveMessages(null, 0, null, null, 0, matchBarrierToken, true);

        if (removed && m != null) {

            if (m.target == null && m.arg1 == token) {

                /* Wake up next() in case it was sleeping on this barrier. */

        if (removed) {

            // Wake up next() in case it was sleeping on this barrier.

            // TODO(b/427541521): optimize wakeup logic to only wake up if we are blocked.

            concurrentWake();

            }

        } else if (!removed) {

        } else {

            throw new IllegalStateException("The specified message queue synchronization "

                    + " barrier token has not been posted or has already been removed.");

        }