bluetooth: mac: Improve classic device discovery and update

device/bluetooth/bluetooth_discovery_manager_mac.mm

 // 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.
 
 #include "device/bluetooth/bluetooth_discovery_manager_mac.h"
 
 #import <IOBluetooth/objc/IOBluetoothDevice.h>
 #import <IOBluetooth/objc/IOBluetoothDeviceInquiry.h>
 
 #include "base/logging.h"
@@ skipping 13 matching lines @@
  @private
   device::BluetoothDiscoveryManagerMacClassic* manager_;  // weak
 }
 
 - (id)initWithManager:(device::BluetoothDiscoveryManagerMacClassic*)manager;
 
 @end
 
 namespace device {
 
-// ementation of BluetoothDiscoveryManagerMac for Bluetooth classic device
+// Implementation of BluetoothDiscoveryManagerMac for Bluetooth classic device
 // discovery, using the IOBluetooth framework.
 class BluetoothDiscoveryManagerMacClassic
     : public BluetoothDiscoveryManagerMac {
  public:
   explicit BluetoothDiscoveryManagerMacClassic(Observer* observer)
       : BluetoothDiscoveryManagerMac(observer),
         should_do_discovery_(false),
         inquiry_running_(false),
         inquiry_delegate_(
             [[BluetoothDeviceInquiryDelegate alloc] initWithManager:this]),
         inquiry_([[IOBluetoothDeviceInquiry alloc]
             initWithDelegate:inquiry_delegate_]) {}
 
   ~BluetoothDiscoveryManagerMacClassic() override {}
 
   // BluetoothDiscoveryManagerMac override.
   bool IsDiscovering() const override { return should_do_discovery_; }
 
   // BluetoothDiscoveryManagerMac override.
   bool StartDiscovery() override {
     DVLOG(1) << "Bluetooth Classic: StartDiscovery";
     DCHECK(!should_do_discovery_);
 
     DVLOG(1) << "Discovery requested";
     should_do_discovery_ = true;
 
+    // Clean the cache so that new discovery sessions find previously
+    // discovered devices as well.
+    [inquiry_ clearFoundDevices];
+
     if (inquiry_running_) {
       DVLOG(1) << "Device inquiry already running";
       return true;
     }
 
     DVLOG(1) << "Requesting to start device inquiry";
     if ([inquiry_ start] != kIOReturnSuccess) {
       DVLOG(1) << "Failed to start device inquiry";
 
       // Set |should_do_discovery_| to false here. Since we're reporting an
@@ skipping 143 matching lines @@
   manager_->DeviceFound(sender, device);
 }
 
 - (void)deviceInquiryComplete:(IOBluetoothDeviceInquiry*)sender
                         error:(IOReturn)error
                       aborted:(BOOL)aborted {
   manager_->DeviceInquiryComplete(sender, error, aborted);
 }
 
 @end