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

mash/quick_launch/quick_launch_application.cc

Index: mash/quick_launch/quick_launch_application.cc
diff --git a/mash/quick_launch/quick_launch_application.cc b/mash/quick_launch/quick_launch_application.cc
index d00baf3ee7b59f900849a030d1c9562977e0d5bf..c4887a4946d1155625859eec23e2ef4ba6763932 100644
--- a/mash/quick_launch/quick_launch_application.cc
+++ b/mash/quick_launch/quick_launch_application.cc
@@ -89,10 +89,9 @@ QuickLaunchApplication::QuickLaunchApplication() {}
 QuickLaunchApplication::~QuickLaunchApplication() {}
 
 void QuickLaunchApplication::Initialize(mojo::Connector* connector,
-                                        const std::string& url,
-                                        const std::string& user_id,
+                                        const mojo::Identity& identity,
                                         uint32_t id) {
-  tracing_.Initialize(connector, url);
+  tracing_.Initialize(connector, identity.name());
 
   aura_init_.reset(new views::AuraInit(connector, "views_mus_resources.pak"));
   views::WindowManagerConnection::Create(connector);