Implement a trivial Mojo EchoService that can be connected to over DBus

mojo/shell/context.cc

Index: mojo/shell/context.cc
diff --git a/mojo/shell/context.cc b/mojo/shell/context.cc
index df86d14bfccdf3670fe5bbdfa2f717c5c7396db8..8f3a4c4b603d3b3a7113ac5615b5e6d5b15d81ad 100644
--- a/mojo/shell/context.cc
+++ b/mojo/shell/context.cc
@@ -10,6 +10,7 @@
 #include "mojo/service_manager/service_loader.h"
 #include "mojo/service_manager/service_manager.h"
 #include "mojo/services/native_viewport/native_viewport_service.h"
+#include "mojo/shell/dbus_service_loader.h"
 #include "mojo/shell/dynamic_service_loader.h"
 #include "mojo/shell/in_process_dynamic_service_runner.h"
 #include "mojo/shell/network_delegate.h"
@@ -66,6 +67,12 @@ Context::Context()
       scoped_ptr<ServiceLoader>(new NativeViewportServiceLoader(this)),
       GURL("mojo:mojo_native_viewport_service"));
 
+#if defined(OS_LINUX)
+  service_manager_.SetLoaderForScheme(
+      scoped_ptr<ServiceLoader>(new DBusServiceLoader(this)),
+      "dbus");
+#endif  // defined(OS_LINUX)
+
   if (cmdline->HasSwitch(switches::kSpy)) {
     spy_.reset(new mojo::Spy(&service_manager_,
                              cmdline->GetSwitchValueASCII(switches::kSpy)));