Prepare chrome to use the new Mojo EDK by default.

mojo/runner/context.cc

Index: mojo/runner/context.cc
diff --git a/mojo/runner/context.cc b/mojo/runner/context.cc
index 3e47f6cf746da1405b2a9d18ae84237087a0a55d..db00a7d7df5f1a596ceab5e8dbc8319bef5f065c 100644
--- a/mojo/runner/context.cc
+++ b/mojo/runner/context.cc
@@ -287,7 +287,9 @@ void Context::Shutdown() {
   TRACE_EVENT0("mojo_shell", "Context::Shutdown");
   DCHECK_EQ(base::MessageLoop::current()->task_runner(),
             task_runners_->shell_runner());
-  embedder::ShutdownIPCSupport();
+  // Post a task in case OnShutdownComplete is called synchronously.
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE, base::Bind(embedder::ShutdownIPCSupport));
   // We'll quit when we get OnShutdownComplete().
   base::MessageLoop::current()->Run();
 }