Add mach ports support to the Mojo shell.

mojo/shell/runner/host/child_process.cc

Index: mojo/shell/runner/host/child_process.cc
diff --git a/mojo/shell/runner/host/child_process.cc b/mojo/shell/runner/host/child_process.cc
index 51915d77790754f50a6f0159f59b10c5e618bc49..260dc66edc70f0fc7f6073d41e8c16aa32de948a 100644
--- a/mojo/shell/runner/host/child_process.cc
+++ b/mojo/shell/runner/host/child_process.cc
@@ -44,6 +44,10 @@
 #include "mojo/shell/runner/host/linux_sandbox.h"
 #endif
 
+#if defined(OS_MACOSX)
+#include "mojo/shell/runner/host/mach_broker.h"
+#endif
+
 namespace mojo {
 namespace shell {
 
@@ -103,6 +107,11 @@ int ChildProcessMain() {
   if (app_library)
     CallLibraryEarlyInitialization(app_library);
 
+#if defined(OS_MACOSX)
+  // Send our task port to the parent.
+  MachBroker::SendTaskPortToParent();
+#endif
+
 #if !defined(OFFICIAL_BUILD)
   // Initialize stack dumping just before initializing sandbox to make
   // sure symbol names in all loaded libraries will be cached.