Handle RESCAN events from the Bluetooth chooser by starting or extending a discovery session.

content/browser/bluetooth/bluetooth_dispatcher_host.h

Index: content/browser/bluetooth/bluetooth_dispatcher_host.h
diff --git a/content/browser/bluetooth/bluetooth_dispatcher_host.h b/content/browser/bluetooth/bluetooth_dispatcher_host.h
index 7e3e7af45cb7d59206db6e04237ee11c962828d7..cc6cd9d5cb21ad43b4cfe9e008f373a6053b5fd7 100644
--- a/content/browser/bluetooth/bluetooth_dispatcher_host.h
+++ b/content/browser/bluetooth/bluetooth_dispatcher_host.h
@@ -59,6 +59,10 @@ class CONTENT_EXPORT BluetoothDispatcherHost final
   // releasing references to previous |adapter_|.
   void set_adapter(scoped_refptr<device::BluetoothAdapter> adapter);
 
+  // Makes sure a BluetoothDiscoverySession is active for |session|, and resets
+  // its timeout.
+  void StartDeviceDiscovery(RequestDeviceSession* session, int chooser_id);
+
   // Stops all BluetoothDiscoverySessions being run for requestDevice()
   // choosers.
   void StopDeviceDiscovery();