Add listener for AdapterDiscoveringChanged on BT chooser-controller

content/browser/bluetooth/bluetooth_device_chooser_controller.h

Index: content/browser/bluetooth/bluetooth_device_chooser_controller.h
diff --git a/content/browser/bluetooth/bluetooth_device_chooser_controller.h b/content/browser/bluetooth/bluetooth_device_chooser_controller.h
index a054d6bf7058b521c3ecfde6c72256fd88122698..ee4c0793cc61735495cfda8256edd15e87b294c7 100644
--- a/content/browser/bluetooth/bluetooth_device_chooser_controller.h
+++ b/content/browser/bluetooth/bluetooth_device_chooser_controller.h
@@ -79,6 +79,10 @@ class CONTENT_EXPORT BluetoothDeviceChooserController final {
   // that the adapter changed states.
   void AdapterPoweredChanged(bool powered);
 
+  // Stops the discovery session and notifies the chooser
+  // when discovery stops accidentally.
+  void AdapterDiscoveringChanged(bool discovering);
+
   // Received Signal Strength Indicator (RSSI) is a measurement of the power
   // present in a received radio signal.
   static int CalculateSignalStrengthLevel(int8_t rssi);