Quit the message loop by default in ShellConnectionLost when ApplicationRunner is used

mash/quick_launch/quick_launch_application.cc

Index: mash/quick_launch/quick_launch_application.cc
diff --git a/mash/quick_launch/quick_launch_application.cc b/mash/quick_launch/quick_launch_application.cc
index 0f505a894d187d920a1813e93f533992fe7b133b..2b2764b80d4680fec241c72a7188b96620c95bc1 100644
--- a/mash/quick_launch/quick_launch_application.cc
+++ b/mash/quick_launch/quick_launch_application.cc
@@ -106,9 +106,5 @@ bool QuickLaunchApplication::AcceptConnection(mojo::Connection* connection) {
   return true;
 }
 
-void QuickLaunchApplication::ShellConnectionLost() {
-  base::MessageLoop::current()->QuitWhenIdle();
-}
-
 }  // namespace quick_launch
 }  // namespace mash