Add a instance groups to Connect(), and introduce an Identity struct.

components/profile_service/profile_app.h

Index: components/profile_service/profile_app.h
diff --git a/components/profile_service/profile_app.h b/components/profile_service/profile_app.h
index 12f0d4ef9c99a115c0fc0bfb08da0cf77d1c9f60..8da3f56e5c1046634c664989ebaed41297d15731 100644
--- a/components/profile_service/profile_app.h
+++ b/components/profile_service/profile_app.h
@@ -56,8 +56,7 @@ class ProfileApp : public mojo::ShellClient,
  private:
   // |ShellClient| override:
   void Initialize(mojo::Connector* connector,
-                  const std::string& url,
-                  const std::string& user_id,
+                  const mojo::Identity& identity,
                   uint32_t id) override;
   bool AcceptConnection(mojo::Connection* connection) override;