Implemented BluetoothTaskManagerWin class.

device/bluetooth/bluetooth_task_manager_win.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 DEVICE_BLUETOOTH_BLUETOOTH_TASK_MANAGER_WIN_H_
+#define DEVICE_BLUETOOTH_BLUETOOTH_TASK_MANAGER_WIN_H_
+
+#include <string>
+#include "base/memory/ref_counted.h"
+#include "base/observer_list.h"
+#include "device/bluetooth/bluetooth_polling_thread_win.h"
+
+class MessageLoop;
+
+namespace device {
+
+// Manages the blocking Bluetooth tasks with a dedicated thread. It owns and
+// runs a thread to perform blocking Bluetooth tasks and informs its observers
+// of bluetooth adapter state changes and any other bluetooth device inquiry
+// result.
+// All the code in this class runs in the UI thread.

[bryeung, 2012/12/10 19:51:28]

This deserves a more thorough comment about why we have two classes for this,
and the ownership/thread conventions that were necessary.

[youngki, 2012/12/17 17:17:23]

I put some more comments to explain the message passing between this class and
the thread, and why this is reference-counted.

+class BluetoothTaskManagerWin
+    : public base::RefCountedThreadSafe<BluetoothTaskManagerWin> {
+ public:
+  struct AdapterState {
+    std::string name;
+    std::string address;
+    bool powered;
+  };
+
+  class Observer {
+   public:
+     virtual ~Observer() {}
+
+     virtual void AdapterStateChanged(const AdapterState& state) {}
+  };
+
+  BluetoothTaskManagerWin();
+
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  void StartThread();
+  void StopThread();
+
+  MessageLoop* message_loop() const { return ui_message_loop_; }
+
+ private:
+  friend class base::RefCountedThreadSafe<BluetoothTaskManagerWin>;
+  friend class BluetoothPollingThreadWin;

[bryeung, 2012/12/10 19:51:28]

why is this necessary?

[youngki, 2012/12/17 17:17:23]

This is necessary so that BluetoothPollingThreadWin can call
OnAdapterStateChanged() below.

+
+  virtual ~BluetoothTaskManagerWin();
+
+  // Notify all Observers of updated AdapterState. Should only be called on the
+  // UI thread.
+  void OnAdapterStateChanged(const AdapterState* state);
+
+  // Main message loop reference.
+  MessageLoop* const ui_message_loop_;
+
+  BluetoothPollingThreadWin thread_;
+
+  // List of observers interested in event notifications.
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(BluetoothTaskManagerWin);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_BLUETOOTH_BLUETOOTH_TASK_MANAGER_WIN_H_