Move shell service to toplevel shell namespace

mash/example/window_type_launcher/window_type_launcher.h

Index: mash/example/window_type_launcher/window_type_launcher.h
diff --git a/mash/example/window_type_launcher/window_type_launcher.h b/mash/example/window_type_launcher/window_type_launcher.h
index 9ea908bf83d868de7e9a68ae91bc4f6caea3dceb..67d32abf2062264c6302bc9a6e17bef7f1dd6106 100644
--- a/mash/example/window_type_launcher/window_type_launcher.h
+++ b/mash/example/window_type_launcher/window_type_launcher.h
@@ -14,14 +14,15 @@ namespace views {
 class AuraInit;
 }
 
-class WindowTypeLauncher : public mojo::ShellClient {
+class WindowTypeLauncher : public shell::ShellClient {
  public:
   WindowTypeLauncher();
   ~WindowTypeLauncher() override;
 
  private:
-  // mojo::ShellClient:
-  void Initialize(mojo::Connector* connector, const mojo::Identity& identity,
+  // shell::ShellClient:
+  void Initialize(shell::Connector* connector,
+                  const shell::Identity& identity,
                   uint32_t id) override;
   bool ShellConnectionLost() override;