Update ProcessCallAfterXms to better match the performance of our faster bots. Previously I had made sure these tests didn't flake out on our slow trybots, but apparently I need to do the same for the fast bots :)

TBR=bjornv@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/40659004

Cr-Commit-Position: refs/heads/master@{#8262}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8262 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/utility/source/process_thread_impl_unittest.cc

@@ -139,7 +139,8 @@ void ProcessCallAfterAFewMs(int64_t milliseconds) {
   EXPECT_CALL(module, Process())
       .WillOnce(DoAll(SetTimestamp(&called_time),
                       SetEvent(event.get()),
-                      Return(0)));
+                      Return(0)))
+      .WillRepeatedly(Return(0));
 
   EXPECT_EQ(0, thread.RegisterModule(&module));