bluetooth: mac: add connected LE devices to chooser

device/bluetooth/bluetooth_low_energy_discovery_manager_mac.mm

 // 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.
 
 #include "device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h"
 
 #include <memory>
 
 #include "base/mac/mac_util.h"
 #include "base/mac/sdk_forward_declarations.h"
@@ skipping 55 matching lines @@
   VLOG(1) << "TryStartDiscovery scanForPeripheralsWithServices";
   // Start a scan with the Allow Duplicates option so that we get notified
   // of each new Advertisement Packet. This allows us to provide up to date
   // values for RSSI, Advertised Services, Advertised Data, etc.
   [central_manager_
       scanForPeripheralsWithServices:services
                              options:@{
                                CBCentralManagerScanOptionAllowDuplicatesKey :
                                    @YES
                              }];
+  NSArray* connectedServices;
+  if (services) {
+    connectedServices = services;
+  } else {
+    CBUUID* defaultService = [CBUUID UUIDWithString:@"1800"];

[François Beaufort, 2016/09/15 07:38:16]

You may want to add a comment there to explain why we've picked "Generic Access"
service UUID:
https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.blu...

In the future, we should consider adding previously connected devices as well. 

[jlebel, 2016/09/21 13:49:28]

Done.

+    connectedServices = @[ defaultService ];
+  }
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wpartial-availability"

[François Beaufort, 2016/09/15 07:38:16]

According to
https://developer.apple.com/reference/corebluetooth/cbcentralmanager/1518924-...,
retrieveConnectedPeripheralsWithServices has been introduced in macOS 10.9.
Shouldn't we update src/base/mac/sdk_forward_declarations.h?

[jlebel, 2016/09/21 13:49:28]

I think it is a terrible idea to create a fake declaration to avoid a compiler
warning. I prefer to be explicit: ask the compiler to not generate the warning.

+  NSArray* peripherals = [central_manager_
+      retrieveConnectedPeripheralsWithServices:connectedServices];
+#pragma clang diagnostic pop
+  for (CBPeripheral* peripheral in peripherals) {
+    observer_->LowEnergyDeviceUpdated(peripheral, nil, 0);

[François Beaufort, 2016/09/15 07:38:16]

Nit:  observer_->LowEnergyDeviceUpdated(peripheral, nil /* advertisementData */,
0 /* rssi */);

[jlebel, 2016/09/21 13:49:28]

Done.

+  }
   pending_ = false;
 }
 
 void BluetoothLowEnergyDiscoveryManagerMac::StopDiscovery() {
   VLOG(1) << "StopDiscovery";
   if (discovering_ && !pending_) {
     [central_manager_ stopScan];
   }
   discovering_ = false;
 }
@@ skipping 17 matching lines @@
 }
 
 BluetoothLowEnergyDiscoveryManagerMac::BluetoothLowEnergyDiscoveryManagerMac(
     Observer* observer)
     : observer_(observer) {
   DCHECK(BluetoothAdapterMac::IsLowEnergyAvailable());
   discovering_ = false;
 }
 
 }  // namespace device