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

components/leveldb/leveldb_app.h

 // 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.
 
 #ifndef COMPONENTS_LEVELDB_LEVELDB_APP_H_
 #define COMPONENTS_LEVELDB_LEVELDB_APP_H_
 
 #include "components/leveldb/public/interfaces/leveldb.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "mojo/services/tracing/public/cpp/tracing_impl.h"
 #include "mojo/shell/public/cpp/interface_factory.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 
 namespace leveldb {
 
 class LevelDBApp : public mojo::ShellClient,
                    public mojo::InterfaceFactory<LevelDBService> {
  public:
   LevelDBApp();
   ~LevelDBApp() override;
 
  private:
   // |ShellClient| override:
   void Initialize(mojo::Connector* connector,
-                  const std::string& url,
-                  const std::string& user_id,
+                  const mojo::Identity& identity,
                   uint32_t id) override;
   bool AcceptConnection(mojo::Connection* connection) override;
 
   // TODO(erg): What do we have to do on shell error?
   // bool OnShellConnectionError() override;
 
   // |InterfaceFactory<LevelDBService>| implementation:
   void Create(mojo::Connection* connection,
               mojo::InterfaceRequest<LevelDBService> request) override;
 
   mojo::TracingImpl tracing_;
   scoped_ptr<LevelDBService> service_;
   mojo::BindingSet<LevelDBService> bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(LevelDBApp);
 };
 
 }  // namespace leveldb
 
 #endif  // COMPONENTS_LEVELDB_LEVELDB_APP_H_