Merge "Transitions can also be aborted after start." into tm-qpr-dev

    void abort() {

        // This calls back into itself via controller.abort, so just early return here.

        if (mState == STATE_ABORT) return;

        if (mState != STATE_COLLECTING) {

            throw new IllegalStateException("Too late to abort.");

        if (mState != STATE_COLLECTING && mState != STATE_STARTED) {

            throw new IllegalStateException("Too late to abort. state=" + mState);

        }

        ProtoLog.v(ProtoLogGroup.WM_DEBUG_WINDOW_TRANSITIONS, "Aborting Transition: %d", mSyncId);

        mState = STATE_ABORT;