Sync when locked object is indirect via method call

[andrecostea]

src/test/java/alarmclock/AlarmClock.java:191: warning: Thread Safety Violation 2
Read/Write race. Non-private method Monitor.wakeme(...) indirectly reads without synchronization from this.waitList.list.[_]. Potentially races with write in method Monitor.tick().
Reporting because this access may occur on a background thread.
189. */
190. try {
191. > synchronized (waitList.getLock(waketime)) {
192. try {
193. waitList.getLock(waketime).wait();