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

mojo/shell/tests/shell/shell_unittest.cc

Index: mojo/shell/tests/shell/shell_unittest.cc
diff --git a/mojo/shell/tests/shell/shell_unittest.cc b/mojo/shell/tests/shell/shell_unittest.cc
index db752bba1e5908bc509ff2bef59dc677a80b2fc3..4a0debf5442c557d16610146c1e00435b1dbfedc 100644
--- a/mojo/shell/tests/shell/shell_unittest.cc
+++ b/mojo/shell/tests/shell/shell_unittest.cc
@@ -127,11 +127,11 @@ class ShellTest : public mojo::test::ShellTest,
   void SetExistingInstances(Array<mojom::InstanceInfoPtr> instances) override {
     for (size_t i = 0; i < instances.size(); ++i) {
       initial_instances_.push_back(InstanceInfo(instances[i]->id,
-                                                instances[i]->name));
+                                                instances[i]->identity->name));
     }
   }
   void InstanceCreated(mojom::InstanceInfoPtr instance) override {
-    instances_.push_back(InstanceInfo(instance->id, instance->name));
+    instances_.push_back(InstanceInfo(instance->id, instance->identity->name));
   }
   void InstanceDestroyed(uint32_t id) override {
     for (auto it = instances_.begin(); it != instances_.end(); ++it) {