Reset Bluetooth EventHandler when it is invalid

chrome/browser/ui/bluetooth/bluetooth_chooser_controller.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 CHROME_BROWSER_UI_BLUETOOTH_BLUETOOTH_CHOOSER_CONTROLLER_H_
 #define CHROME_BROWSER_UI_BLUETOOTH_BLUETOOTH_CHOOSER_CONTROLLER_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 36 matching lines @@
   // discovery is happening.
   void OnDiscoveryStateChanged(content::BluetoothChooser::DiscoveryState state);
 
   // Shows a new device in the chooser.
   void AddDevice(const std::string& device_id,
                  const base::string16& device_name);
 
   // Tells the chooser that a device is no longer available.
   void RemoveDevice(const std::string& device_id);
 
+  // Called when |event_handler_| is no longer valid and should not be used
+  // any more.
+  void ResetEventHandler();
+
  private:
   // Clears |device_names_and_ids_| and |device_name_map_|. Called when
   // Bluetooth adapter is turned on or off, or when re-scan happens.
   void ClearAllDevices();
 
   // Each pair is a (device name, device id).
   std::vector<std::pair<base::string16, std::string>> device_names_and_ids_;
   content::BluetoothChooser::EventHandler event_handler_;
   // Maps from device name to number of devices.
   std::unordered_map<base::string16, int> device_name_map_;
   base::string16 no_devices_text_;
   base::string16 status_text_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothChooserController);
 };
 
 #endif  // CHROME_BROWSER_UI_BLUETOOTH_BLUETOOTH_CHOOSER_CONTROLLER_H_