Don't wait until distant future to shut down video app.

BUG=
R=pbos@webrtc.org

Review URL: https://codereview.webrtc.org/1415033005 .

Cr-Commit-Position: refs/heads/master@{#10387}

webrtc/test/mac/run_test.mm

@@ -65,7 +65,7 @@ void RunTest(void(*test)()) {
   NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
   while ([testRunner running] &&
          [runLoop runMode:NSDefaultRunLoopMode
-               beforeDate:[NSDate distantFuture]]);
+               beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.1]]);
 
   [testRunner release];
   [pool release];