Start app shim when app launched.

apps/app_shim/app_shim_handler_mac.h

Index: apps/app_shim/app_shim_handler_mac.h
diff --git a/apps/app_shim/app_shim_handler_mac.h b/apps/app_shim/app_shim_handler_mac.h
index 507fe5f8410b055ea8f5cd26d3a3fcbb0ca6566d..28e0fae60510c1759480eed69bc437f6800d8a19 100644
--- a/apps/app_shim/app_shim_handler_mac.h
+++ b/apps/app_shim/app_shim_handler_mac.h
@@ -46,8 +46,9 @@ class AppShimHandler {
 
   // Invoked by the shim host when the shim process is launched. The handler
   // must return true if successful, or false to indicate back to the shim
-  // process that it should close.
-  virtual bool OnShimLaunch(Host* host) = 0;
+  // process that it should close. |launch_now| indicates whether to launch the
+  // associated app.
+  virtual bool OnShimLaunch(Host* host, bool launch_now) = 0;
 
   // Invoked by the shim host when the connection to the shim process is closed.
   virtual void OnShimClose(Host* host) = 0;