Add status service for remoting host.

remoting/host/host_status_service.h

Index: remoting/host/host_status_service.h
diff --git a/remoting/host/host_status_service.h b/remoting/host/host_status_service.h
new file mode 100644
index 0000000000000000000000000000000000000000..f2d9a233e0f33cf9652a00485e512f450325489a
--- /dev/null
+++ b/remoting/host/host_status_service.h
@@ -0,0 +1,63 @@
+// Copyright (c) 2012 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_STATUS_SERVICE_H_
+#define REMOTING_HOST_HOST_STATUS_SERVICE_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "remoting/host/websocket_listener.h"
+
+namespace base {
+class DictionaryValue;
+}  // namespace remoting
+
+namespace remoting {
+
+// HostStatusService implements WebSocket server that communicates with the
+// remoting web app and lets it get current status of the host.

[Wez, 2012/11/20 05:55:53]

nit: "HostStatusService implements a WebSocket server for the remoting web app
to use to query the current status of the host"

[Sergey Ulanov, 2012/11/22 00:29:35]

Done.

+class HostStatusService {
+ public:
+  HostStatusService();
+  ~HostStatusService();
+
+  // Must be called whenever state of the host changes.
+  void SetHostIsUp(const std::string& host_id);
+  void SetHostIsDown();
+
+ private:
+  class Connection;
+  friend class Connection;
+
+  // A helper to validate origin of an incoming connection.
+  static bool IsAllowedOrigin(const std::string& origin);
+
+  // Callback from WebsocketListener.
+  void OnNewConnection(scoped_ptr<WebsocketConnection> connection);
+
+  // Called from Connection instances when |connection| is closed and the
+  // Connection object should be destroyed.
+  void OnConnectionClosed(Connection* connection);
+
+  // Creates a status message that should be sent as a response to an incoming
+  // getHostState message.
+  scoped_ptr<base::DictionaryValue> GetStatusMessage();
+
+  WebsocketListener websocket_listener_;
+  std::set<Connection*> connections_;
+
+  // Host name we expect in incoming connections, e.g. "localhost:12810".
+  std::string service_host_name_;
+
+  // Current state of the host to provide to clients.
+  bool started_;
+  std::string host_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(HostStatusService);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_HOST_STATUS_SERVICE_H_