Accept inbound connections on unix domain socket

mojo/shell/switches.cc

Index: mojo/shell/switches.cc
diff --git a/mojo/shell/switches.cc b/mojo/shell/switches.cc
index cf3697f645a76e11413b9c6bd21643d785dff18a..b3f2ac3c2ea08929bbb37a4801c166af4abad31b 100644
--- a/mojo/shell/switches.cc
+++ b/mojo/shell/switches.cc
@@ -18,6 +18,11 @@ const char kContentHandlers[] = "content-handlers";
 // instructions.
 const char kDisableCache[] = "disable-cache";
 
+// Allow externally-running applications to discover, connect to, and register
+// themselves with the shell.
+// TODO(cmasone): Work in progress. Once we're sure this works, remove.
+const char kEnableExternalApplications[] = "enable-external-applications";
+
 // Load apps in separate processes.
 // TODO(vtl): Work in progress; doesn't work. Flip this to "disable" (or maybe
 // change it to "single-process") when it works.