device/bluetooth: Clean up classic discovery in BluetoothAdapterMac.

device/bluetooth/bluetooth_mac_discovery_manager.h

+// Copyright 2014 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_MAC_DISCOVERY_MANAGER_H_
+#define DEVICE_BLUETOOTH_BLUETOOTH_MAC_DISCOVERY_MANAGER_H_
+
+#include "base/observer_list.h"
+
+@class IOBluetoothDevice;
+
+namespace device {
+
+// Class used by BluetoothAdapterMac to manage classic and LE device discovery.
+// For Bluetooth Classic, this class is responsible for keeping device inquiry
+// running if device discovery is initiated.
+class BluetoothMacDiscoveryManager {
+ public:
+  // Interface for being notified of events during a device discovery session.
+  class Observer {
+   public:
+    // Called when |manager| has found a device through classic device inquiry
+    // in the form of a IOBluetoothDevice.
+    virtual void DeviceFound(BluetoothMacDiscoveryManager* manager,
+                             IOBluetoothDevice* device) {}
+
+    // Called when device discovery is no longer running, due to either a call
+    // too BluetoothMacDiscoveryManager::StopDiscovery or an unexpected reason,

[Ilya Sherman, 2014/06/10 01:10:59]

nit: "too" -> "to"

[armansito, 2014/06/10 21:56:50]

Done.

+    // such as when a user disables the controller, in which case the value of
+    // |unexpected| will be true.
+    virtual void DiscoveryStopped(BluetoothMacDiscoveryManager* manager,
+                                  bool unexpected) {}
+  };
+
+  virtual ~BluetoothMacDiscoveryManager();
+
+  // Returns true, if discovery is currently being performed.
+  virtual bool IsDiscovering() const = 0;
+
+  // Initiates a discovery session. Returns true on success, or if discovery
+  // is already running.

[Ilya Sherman, 2014/06/10 01:10:59]

nit: It visually looks like this comment applies to both methods below it; but
it really only describes one of the two.

[armansito, 2014/06/10 21:56:50]

Done.

+  virtual bool StartDiscovery() = 0;
+  virtual bool StopDiscovery() = 0;
+
+  // Add and remove observers.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // Creates a discovery manager for Bluetooth Classic device discovery.
+  static BluetoothMacDiscoveryManager* CreateClassic();
+
+ protected:
+  BluetoothMacDiscoveryManager();
+
+  // List of observers interested in notifications from us.
+  ObserverList<Observer> observers_;

[Ilya Sherman, 2014/06/10 01:10:59]

Do we really need a list of observers, or can we just have a single observer
that's set during construction?

[armansito, 2014/06/10 21:56:50]

We can have a single observer, certainly. This just seemed a bit more generic
and cleaner to me but I don't have a preference, so I'll change it if you
insist.

[Ilya Sherman, 2014/06/10 23:23:01]

I won't insist, but IMO it's better to avoid being generic when it's not
necessary.

[armansito, 2014/06/13 02:14:53]

Done.

+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BluetoothMacDiscoveryManager);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_BLUETOOTH_BLUETOOTH_MAC_DISCOVERY_MANAGER_H_