[Chromoting] GetHostAttributes with tests

remoting/host/host_attributes.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 REMOTING_HOST_HOST_ATTRIBUTES_H_
+#define REMOTING_HOST_HOST_ATTRIBUTES_H_
+
+#include <map>
+#include <set>
+#include <string>
+
+#include "base/callback.h"
+
+namespace remoting {
+
+class HostAttributes final {
+ public:
+  HostAttributes();
+  HostAttributes(HostAttributes&& other);
+  HostAttributes(const HostAttributes& other);
+  ~HostAttributes();
+
+  HostAttributes& operator=(HostAttributes&& other);
+  HostAttributes& operator=(const HostAttributes& other);
+
+  // Converts the HostAttributes into its text representation, which is a comma-
+  // separated string, each field indicates one attribute.
+  std::string ToString() const;
+
+  // Registers a static value, which will be appended to ToString() result.
+  void Register(const std::string& key);
+
+  // Registers a dynamic value, which will be evaluated each time ToString() is
+  // called.
+  void Register(const std::string& key, const base::Callback<bool()>& value);
+
+  // Whether the |output| contains the specified attribute as |key|. This
+  // function is usually for testing purpose.
+  static bool ContainsAttribute(const std::string& output,
+                                const std::string& key);
+
+ private:
+  std::set<std::string> static_values_;
+  std::map<std::string, base::Callback<bool()>> dynamic_values_;

[Sergey Ulanov, 2016/11/03 22:15:34]

I still think we don't need set/map here instead of vector<>. It's possible to
verify presence of duplicate entries using std::find()

[Hzj_jie, 2016/11/05 05:29:28]

I have moved this logic into the test case.

+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_HOST_ATTRIBUTES_H_