[mojo-edk] Simplify multiprocess pipe bootstrap

mash/shell/shell_application_delegate.cc

Index: mash/shell/shell_application_delegate.cc
diff --git a/mash/shell/shell_application_delegate.cc b/mash/shell/shell_application_delegate.cc
index 68c01fd6807ab5092cfd18a893e91dae2e32e801..4c2196e6e99068d286b42c9d180f07508e56aa1f 100644
--- a/mash/shell/shell_application_delegate.cc
+++ b/mash/shell/shell_application_delegate.cc
@@ -117,8 +117,12 @@ void ShellApplicationDelegate::StartRestartableService(
   // TODO(beng): This would be the place to insert logic that counted restarts
   //             to avoid infinite crash-restart loops.
   scoped_ptr<mojo::Connection> connection = shell_->Connect(url);
-  connection->SetRemoteServiceProviderConnectionErrorHandler(restart_callback);
-  connections_[url] = std::move(connection);
+  // Note: |connection| may be null if we've lost our connection to the shell.
+  if (connection) {
+    connection->SetRemoteServiceProviderConnectionErrorHandler(
+        restart_callback);
+    connections_[url] = std::move(connection);
+  }
 }
 
 }  // namespace shell