Add listener for AdapterDiscoveringChanged on BT chooser-controller

content/browser/bluetooth/web_bluetooth_service_impl.h

 // Copyright 2016 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 CONTENT_BROWSER_BLUETOOTH_WEB_BLUETOOTH_SERVICE_IMPL_H_
 #define CONTENT_BROWSER_BLUETOOTH_WEB_BLUETOOTH_SERVICE_IMPL_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 60 matching lines @@
       PrimaryServicesRequestCallback;
 
   // WebContentsObserver:
   // These functions should always check that the affected RenderFrameHost
   // is this->render_frame_host_ and not some other frame in the same tab.
   void DidFinishNavigation(NavigationHandle* navigation_handle) override;
 
   // BluetoothAdapter::Observer:
   void AdapterPoweredChanged(device::BluetoothAdapter* adapter,
                              bool powered) override;
+  void AdapterDiscoveringChanged(device::BluetoothAdapter* adapter,
+                                 bool discovering) override;
   void DeviceAdded(device::BluetoothAdapter* adapter,
                    device::BluetoothDevice* device) override;
   void DeviceChanged(device::BluetoothAdapter* adapter,
                      device::BluetoothDevice* device) override;
   void GattServicesDiscovered(device::BluetoothAdapter* adapter,
                               device::BluetoothDevice* device) override;
   void GattCharacteristicValueChanged(
       device::BluetoothAdapter* adapter,
       device::BluetoothRemoteGattCharacteristic* characteristic,
       const std::vector<uint8_t>& value) override;
@@ skipping 187 matching lines @@
   mojo::Binding<blink::mojom::WebBluetoothService> binding_;
 
   base::WeakPtrFactory<WebBluetoothServiceImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WebBluetoothServiceImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_BLUETOOTH_WEB_BLUETOOTH_SERVICE_IMPL_H_