Make testSetTextLong() wait for its work to finish.

Previously, rendering the long text run in the test could go on
during the setUp of the next test method, making the next test to
time out and fail.

Now, we just wait for the work to finish before we declare the test
done.

Bug: 18088201
Change-Id: I3dfd64ae1adc916bccd399e1cca67a9d388666c4
1 file changed