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

components/profile_service/profile_app.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/profile_service/profile_app.h"
 
 #include "base/lazy_instance.h"
 #include "components/leveldb/leveldb_service_impl.h"
 #include "components/profile_service/profile_service_impl.h"
 #include "mojo/shell/public/cpp/connection.h"
@@ skipping 18 matching lines @@
 ProfileApp::~ProfileApp() {}
 
 // static
 void ProfileApp::AssociateMojoUserIDWithProfileDir(
     const std::string& user_id,
     const base::FilePath& profile_data_dir) {
   g_user_id_to_data_dir.Get()[user_id] = profile_data_dir;
 }
 
 void ProfileApp::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());
   leveldb_service_.reset(new leveldb::LevelDBServiceImpl);
 
-  auto it = g_user_id_to_data_dir.Get().find(user_id);
+  auto it = g_user_id_to_data_dir.Get().find(identity.user_id());
   DCHECK(it != g_user_id_to_data_dir.Get().end());
   profile_data_dir_ = it->second;
 }
 
 bool ProfileApp::AcceptConnection(mojo::Connection* connection) {
   connection->AddInterface<leveldb::LevelDBService>(this);
   connection->AddInterface<ProfileService>(this);
   return true;
 }
 
 void ProfileApp::Create(mojo::Connection* connection,
                         ProfileServiceRequest request) {
   // No, we need one of these per connection.
   new ProfileServiceImpl(connection,
                          std::move(request),
                          profile_data_dir_,
                          lock_table_.get());
 }
 
 void ProfileApp::Create(mojo::Connection* connection,
                         leveldb::LevelDBServiceRequest request) {
   leveldb_bindings_.AddBinding(leveldb_service_.get(), std::move(request));
 }
 
 }  // namespace profile