Introduce empty IBusDaemonController class.

chromeos/ime/ibus_daemon_controller.h

+// 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 CHROMEOS_IME_IBUS_DAEMON_CONTROLLER_H_
+#define CHROMEOS_IME_IBUS_DAEMON_CONTROLLER_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/sequenced_task_runner.h"
+#include "chromeos/chromeos_export.h"
+
+namespace chromeos {
+
+// IBusDaemonController is used to start/stop ibus-daemon process. This class is
+// also watching ibus-daemon process and if it is crashed, re-launch it
+// automatically. This class is managed as Singleton.
+class CHROMEOS_EXPORT IBusDaemonController {
+ public:
+  class Observer {
+   public:
+    // Called when the connection with ibus-daemon is established.
+    virtual void OnConnected() = 0;
+
+    // Called when the connection with ibus-daemon is lost.
+    virtual void OnDisconnected() = 0;
+  };
+
+  virtual ~IBusDaemonController();
+
+  // Initializes IBusDaemonController. ibus-daemon related file handling is
+  // posted to |file_task_runner|.
+  virtual void Initialize(
+      const scoped_refptr<base::SequencedTaskRunner>& ui_task_runner,
+      const scoped_refptr<base::SequencedTaskRunner>& file_task_runner) = 0;
+
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
+
+  // Starts ibus-daemon.
+  virtual bool Start() = 0;
+
+  // Stops ibus-daemon.
+  virtual bool Stop() = 0;
+
+  // Returns actual implementation of IBusDaemonController. If the browser is
+  // not running on the Chrome OS device, this function returns stub
+  // implementation.
+  static CHROMEOS_EXPORT IBusDaemonController* GetInstance();
+
+ protected:
+  // IBusDaemonController is managed as singleton. USe GetInstance instead.
+  IBusDaemonController();
+
+  DISALLOW_COPY_AND_ASSIGN(IBusDaemonController);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_IME_IBUS_DAEMON_CONTROLLER_H_