Added bluetooth LE support on Mac platform

device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h

+// Copyright 2015 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_LOW_ENERGY_DISCOVER_MANAGER_MAC_H_

[armansito, 2015/01/24 17:59:37]

The header is named *_discovery_manager_* but everything else is named "discover
manager" (without the 'y'). Please name this class *DiscoveryManager* and update
the header guards.

[dvh, 2015/01/27 00:14:55]

Done.

+#define DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_DISCOVER_MANAGER_MAC_H_
+
+#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
+#import <CoreBluetooth/CoreBluetooth.h>
+#else
+#import <IOBluetooth/IOBluetooth.h>
+#endif
+
+#include "base/mac/scoped_nsobject.h"
+
+#include "device/bluetooth/bluetooth_device.h"
+
+@class BluetoothLowEnergyDiscoverManagerMacBridge;
+
+namespace device {
+
+class BluetoothLowEnergyDeviceMac;
+class BluetoothLowEnergyDiscoverManagerMacDelegate;
+
+// This class will scan for bluetooth LE device on Mac.
+class BluetoothLowEnergyDiscoverManagerMac {

[armansito, 2015/01/24 17:59:37]

This class should inherit from BluetoothDiscoveryManagerMac. The idea is that
you would then call BluetoothDiscoveryManagerMac::CreateLowEnergy() (which you
would add), which would then return a BluetoothLowEnergyDiscoveryManagerMac.

[dvh, 2015/01/27 00:14:55]

Does it make sense to inherit from BluetoothDiscoveryManagerMac if
CreateLowEnergy() returns an explicit instance of
BluetoothLowEnergyDiscoveryManagerMac?

The alternative is for CreateLowEnergy() to return a
BluetoothDiscoveryManagerMac. Though, this option doesn't work great since
BluetoothDiscoveryManagerMac::observer works with IOBluetooth objects whereas
low energy alternative works with BluetoothLowEnergyDeviceMac.

Let me know if you have some specific suggestions.

[armansito, 2015/01/29 04:37:18]

No, I like keeping the LE stuff separate from BluetoothDiscoveryManagerMac, we
get this nice isolation from it. The inheritance is mostly organizational. We
don't make use of any polymorphism here but I think its nice to say that these
two DiscoveryManager classes conform to the same interface.

+ public:
+  // Interface for being notified of events during a device discovery session.
+  class Observer {
+   public:
+    // Called when |this| manager has found a device.
+    virtual void DeviceFound(BluetoothLowEnergyDeviceMac* device) = 0;
+
+    // Called when |this| manager has updated on a device.
+    virtual void DeviceUpdated(BluetoothLowEnergyDeviceMac* device) = 0;
+  };
+
+  virtual ~BluetoothLowEnergyDiscoverManagerMac();
+
+  // Returns true, if discovery is currently being performed.
+  virtual bool IsDiscovering() const;
+
+  // Initiates a discovery session.
+  // BluetoothLowEnergyDeviceMac objects discovered within a previous
+  // discovery session will be invalid.
+  virtual void StartDiscovery(BluetoothDevice::UUIDList services_uuids);
+
+  // Stops a discovery session.
+  virtual void StopDiscovery();
+
+  // Returns a new BluetoothLowEnergyDiscoverManagerMac.
+  static BluetoothLowEnergyDiscoverManagerMac* Create(Observer* observer);
+
+ protected:
+  // Called when a discovery or an update of a BLE device occurred.
+  virtual void DiscoveredPeripheral(CBPeripheral* peripheral,
+                                    NSDictionary* advertisementData, int rssi);

[armansito, 2015/01/24 17:59:38]

nit: new line after this method

[dvh, 2015/01/27 00:14:55]

Done.

+  // The device discovery can really be started when bluetooth is powered on.
+  // The method TryStartDiscovery() is called when it's a good time to try to
+  // start the BLE device discovery. It will check if the discovery session has
+  // been started and if the bluetooth is powered and then really start the
+  // CoreBluetooth BLE device discovery.
+  virtual void TryStartDiscovery();
+
+ private:
+  explicit BluetoothLowEnergyDiscoverManagerMac(Observer* observer);
+  void ClearDevices();
+
+  friend class BluetoothLowEnergyDiscoverManagerMacDelegate;
+
+  // Observer interested in notifications from us.

[armansito, 2015/01/24 17:59:37]

nit: Please add a new line after member declarations if the following member
declaration is preceded by a comment.

[dvh, 2015/01/27 00:14:55]

Done.

+  Observer* observer_;
+  // Underlaying CoreBluetooth central manager.
+  base::scoped_nsobject<CBCentralManager> manager_;
+  // Discovery has been initiated by calling the API StartDiscovery().
+  bool discovering_;
+  // A discovery has been initiated but has not started yet because it's
+  // waiting for bluetooth to turn on.
+  bool pending_;
+  // Delegate of the central manager.
+  base::scoped_nsobject<BluetoothLowEnergyDiscoverManagerMacBridge> bridge_;
+  // Map of the device identifiers to the discovered device.
+  std::map<const std::string, BluetoothLowEnergyDeviceMac*> devices_;
+  // List of service UUIDs to scan.
+  BluetoothDevice::UUIDList services_uuids_;
+
+  DISALLOW_COPY_AND_ASSIGN(BluetoothLowEnergyDiscoverManagerMac);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_DEVICE_MAC_H_