bluetooth: Implement hardware filtering on macOS

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_DISCOVERY_MANAGER_MAC_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_DISCOVERY_MANAGER_MAC_H_
 
 #if defined(OS_IOS)
 #import <CoreBluetooth/CoreBluetooth.h>
 #else
@@ skipping 24 matching lines @@
   };
 
   virtual ~BluetoothLowEnergyDiscoveryManagerMac();
 
   // 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);
+  virtual void StartDiscovery(std::set<BluetoothUUID> services_uuids);
+
+  // Updates the scan request to stop scanning for |uuids_to_remove| if
+  // no other filter is scanning for those uuids.

[Jeffrey Yasskin, 2016/08/23 21:37:04]

We don't have the concept of a filter in this class's interface, so you should
describe the condition some other way. Maybe say that StartDiscovery() adds the
UUIDs to a multiset of active UUIDs,and RemoveDiscoveryUUIDs() removes them, and
discovery will be active for any UUID in that multiset?

+  virtual void RemoveDiscoveryUUIDs(std::set<BluetoothUUID> uuids_to_remove);
 
   // Stops a discovery session.
   virtual void StopDiscovery();
 
   // Returns a new BluetoothLowEnergyDiscoveryManagerMac.
   static BluetoothLowEnergyDiscoveryManagerMac* Create(Observer* observer);
 
   virtual void SetCentralManager(CBCentralManager* central_manager);
 
  protected:
@@ skipping 21 matching lines @@
   // Underlying CoreBluetooth central manager, owned by |observer_|.
   CBCentralManager* central_manager_ = nil;
 
   // 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_;
 
-  // List of service UUIDs to scan.
-  BluetoothDevice::UUIDList services_uuids_;
+  // List of service UUIDs to scan for to the number of filters that have that

[Jeffrey Yasskin, 2016/08/23 21:37:04]

s/list/map/?

+  // UUID.
+  std::unordered_map<device::BluetoothUUID, size_t, device::BluetoothUUIDHash>
+      scan_uuids_to_filter_count_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothLowEnergyDiscoveryManagerMac);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_LOW_ENERGY_DISCOVERY_MANAGER_MAC_H_