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

mash/task_viewer/task_viewer.h

Index: mash/task_viewer/task_viewer.h
diff --git a/mash/task_viewer/task_viewer.h b/mash/task_viewer/task_viewer.h
index 0a696cdb07ef92d56c3a7c72fade1124a134cd0c..e5eeae09119b352d91ff35f1f64a5f3ec80d4c7f 100644
--- a/mash/task_viewer/task_viewer.h
+++ b/mash/task_viewer/task_viewer.h
@@ -27,8 +27,9 @@ class TaskViewer : public mojo::ShellClient {
 
  private:
   // mojo::ShellClient:
-  void Initialize(mojo::Connector* connector, const std::string& url,
-                  const std::string& user_id, uint32_t id) override;
+  void Initialize(mojo::Connector* connector,
+                  const mojo::Identity& identity,
+                  uint32_t id) override;
 
   mojo::TracingImpl tracing_;
   scoped_ptr<views::AuraInit> aura_init_;