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

content/common/mojo/mojo_shell_connection_impl.cc

Index: content/common/mojo/mojo_shell_connection_impl.cc
diff --git a/content/common/mojo/mojo_shell_connection_impl.cc b/content/common/mojo/mojo_shell_connection_impl.cc
index eb11c9695feeef71d1dbf93448e4b188f2071b2e..839e206abcf42ab7aac256c581a94c2fcdfed34d 100644
--- a/content/common/mojo/mojo_shell_connection_impl.cc
+++ b/content/common/mojo/mojo_shell_connection_impl.cc
@@ -95,8 +95,7 @@ void MojoShellConnectionImpl::WaitForShell(
 }
 
 void MojoShellConnectionImpl::Initialize(mojo::Connector* connector,
-                                         const std::string& url,
-                                         const std::string& user_id,
+                                         const mojo::Identity& identity,
                                          uint32_t id) {
   initialized_ = true;
 }