Don't use GCD for main thread callbacks in converter, because on 10.8 the messages are not received.
Don't use GCD for main thread callbacks in converter, because on 10.8 the messages are not received.

JackieXie168/skim,JackieXie168/skim,JackieXie168/skim,JackieXie168/skim,JackieXie168/skim