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

mojo/shell/identity.h

-// Copyright 2015 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 MOJO_SHELL_IDENTITY_H_
-#define MOJO_SHELL_IDENTITY_H_
-
-#include <stdint.h>
-
-#include <map>
-#include <set>
-#include <string>
-
-namespace mojo {
-namespace shell {
-
-// A set of names of interfaces that may be exposed to an application.
-using AllowedInterfaces = std::set<std::string>;
-// A map of allowed applications to allowed interface sets. See shell.mojom for
-// more details.
-using CapabilityFilter = std::map<std::string, AllowedInterfaces>;
-
-// Represents the identity of an application.
-// |name| is the structured name of the application.
-// |qualifier| is a string that allows to tie a specific instance of an
-// application to another. A typical use case of qualifier is to control process
-// grouping for a given application name. For example, the core services are
-// grouped into "Core"/"Files"/"Network"/etc. using qualifier; content handler's
-// qualifier is derived from the origin of the content.
-class Identity {
- public:
-  Identity();
-  // Assumes user = mojom::kRootUserID.
-  // Used in tests or for shell-initiated connections.
-  explicit Identity(const std::string& in_name);
-  Identity(const std::string& in_name,
-           const std::string& in_qualifier,
-           const std::string& user_id);
-  Identity(const Identity& other);
-  ~Identity();
-
-  bool operator<(const Identity& other) const;
-  bool is_null() const { return name_.empty(); }
-  bool operator==(const Identity& other) const;
-
-  const std::string& name() const { return name_; }
-  const std::string& user_id() const { return user_id_; }
-  void set_user_id(const std::string& user_id) { user_id_ = user_id; }
-  const std::string& qualifier() const { return qualifier_; }
-  void set_filter(const CapabilityFilter& filter) { filter_ = filter; }
-  const CapabilityFilter& filter() const { return filter_; }
-
- private:
-  std::string name_;
-  std::string qualifier_;
-
-  std::string user_id_;
-
-  // TODO(beng): CapabilityFilter is not currently included in equivalence
-  //             checks for Identity since we're not currently clear on the
-  //             policy for instance disambiguation. Need to figure this out.
-  //             This field is supplied because it is logically part of the
-  //             instance identity of an application.
-  CapabilityFilter filter_;
-};
-
-// Creates an identity for the Shell, used when the Shell connects to
-// applications.
-Identity CreateShellIdentity();
-
-// Returns a capability filter that allows an application to connect to any
-// other application and any service exposed by other applications.
-CapabilityFilter GetPermissiveCapabilityFilter();
-
-// Returns the set of interfaces that an application instance with |filter| is
-// allowed to see from an instance with |identity|.
-AllowedInterfaces GetAllowedInterfaces(const CapabilityFilter& filter,
-                                       const Identity& identity);
-
-}  // namespace shell
-}  // namespace mojo
-
-#endif  // MOJO_SHELL_IDENTITY_H_