diff --git a/packages/flutter_tools/doc/daemon.md b/packages/flutter_tools/doc/daemon.md
index b8383e1..65bbb6a 100644
--- a/packages/flutter_tools/doc/daemon.md
+++ b/packages/flutter_tools/doc/daemon.md
@@ -166,6 +166,22 @@
 
 This is sent once a web application is being served and available for the user to access. The `params` field will be a map with a string `url` field and a boolean `launched` indicating whether the application has already been launched in a browser (this will generally be true for a browser device unless `--no-web-browser-launch` was used, and false for the headless `web-server` device).
 
+### Daemon-to-Editor Requests
+
+These requests come _from_ the Flutter daemon and should be responded to by the client/editor.
+
+#### app.exposeUrl
+
+This request is enabled only if `flutter run` is run with the `--web-allow-expose-url` flag.
+
+This request is sent by the server when it has a local URL that needs to be exposed to the end user. This is to support running on a remote machine where a URL (for example `http://localhost:1234`) may not be directly accessible to the end user. With this URL clients can perform tunnelling and then provide the tunneled URL back to Flutter so that it can be used in code that will be executed on the end users machine (for example wehen a web application needs to be able to connect back to a service like the DWDS debugging service).
+
+This request will only be sent if a web application was run in a mode that requires mapped URLs (such as using `--no-web-browser-launch` for browser devices or the headless `web-server` device when debugging).
+
+The request will contain an `id` field and a `params` field that is a map containing a string `url` field.
+
+The response should be sent using the same `id` as the request with a `result` map containing the mapped `url` (or the same URL in the case where the client does not need to perform any mapping).
+
 ### device domain
 
 #### device.getDevices
diff --git a/packages/flutter_tools/lib/src/base/net.dart b/packages/flutter_tools/lib/src/base/net.dart
index 5df2558..c52ffbd 100644
--- a/packages/flutter_tools/lib/src/base/net.dart
+++ b/packages/flutter_tools/lib/src/base/net.dart
@@ -16,6 +16,8 @@
 
 typedef HttpClientFactory = HttpClient Function();
 
+typedef UrlTunneller = Future<String> Function(String url);
+
 /// Download a file from the given URL.
 ///
 /// If a destination file is not provided, returns the bytes.
diff --git a/packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart b/packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart
index b13f632..5be3196 100644
--- a/packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart
+++ b/packages/flutter_tools/lib/src/build_runner/resident_web_runner.dart
@@ -17,6 +17,7 @@
 import '../base/file_system.dart';
 import '../base/io.dart';
 import '../base/logger.dart';
+import '../base/net.dart';
 import '../base/os.dart';
 import '../base/terminal.dart';
 import '../base/utils.dart';
@@ -47,6 +48,7 @@
     @required bool ipv6,
     @required DebuggingOptions debuggingOptions,
     @required List<String> dartDefines,
+    @required UrlTunneller urlTunneller,
   }) {
     if (featureFlags.isWebIncrementalCompilerEnabled && debuggingOptions.buildInfo.isDebug) {
       return _ExperimentalResidentWebRunner(
@@ -57,6 +59,7 @@
         ipv6: ipv6,
         stayResident: stayResident,
         dartDefines: dartDefines,
+        // TODO(dantup): If this becomes default it may need to urlTunneller.
       );
     }
     return _DwdsResidentWebRunner(
@@ -67,6 +70,7 @@
       ipv6: ipv6,
       stayResident: stayResident,
       dartDefines: dartDefines,
+      urlTunneller: urlTunneller,
     );
   }
 }
@@ -550,6 +554,7 @@
     @required FlutterProject flutterProject,
     @required bool ipv6,
     @required DebuggingOptions debuggingOptions,
+    @required this.urlTunneller,
     bool stayResident = true,
     @required List<String> dartDefines,
   }) : super(
@@ -562,6 +567,8 @@
           dartDefines: dartDefines,
         );
 
+  UrlTunneller urlTunneller;
+
   @override
   Future<int> run({
     Completer<DebugConnectionInfo> connectionInfoCompleter,
@@ -606,6 +613,7 @@
           initializePlatform: debuggingOptions.initializePlatform,
           hostname: debuggingOptions.hostname,
           port: debuggingOptions.port,
+          urlTunneller: urlTunneller,
           skipDwds: !_enableDwds,
           dartDefines: dartDefines,
         );
diff --git a/packages/flutter_tools/lib/src/build_runner/web_fs.dart b/packages/flutter_tools/lib/src/build_runner/web_fs.dart
index c8c0d7a..b996a67 100644
--- a/packages/flutter_tools/lib/src/build_runner/web_fs.dart
+++ b/packages/flutter_tools/lib/src/build_runner/web_fs.dart
@@ -26,6 +26,7 @@
 import '../base/context.dart';
 import '../base/file_system.dart';
 import '../base/io.dart';
+import '../base/net.dart';
 import '../base/os.dart';
 import '../base/platform.dart';
 import '../build_info.dart';
@@ -69,6 +70,7 @@
   LogWriter logWriter,
   bool verbose,
   bool enableDebugExtension,
+  UrlEncoder urlEncoder,
 });
 
 /// A function with the same signature as [WebFs.start].
@@ -80,6 +82,7 @@
   @required bool initializePlatform,
   @required String hostname,
   @required String port,
+  @required UrlTunneller urlTunneller,
   @required List<String> dartDefines,
 });
 
@@ -175,6 +178,7 @@
     @required bool initializePlatform,
     @required String hostname,
     @required String port,
+    @required UrlTunneller urlTunneller,
     @required List<String> dartDefines,
   }) async {
     // workaround for https://github.com/flutter/flutter/issues/38290
@@ -298,6 +302,7 @@
           serveDevTools: false,
           verbose: false,
           enableDebugExtension: true,
+          urlEncoder: urlTunneller,
           logWriter: (dynamic level, String message) => printTrace(message),
         );
         handler = pipeline.addHandler(dwds.handler);
diff --git a/packages/flutter_tools/lib/src/commands/daemon.dart b/packages/flutter_tools/lib/src/commands/daemon.dart
index a53b373..d4dd562 100644
--- a/packages/flutter_tools/lib/src/commands/daemon.dart
+++ b/packages/flutter_tools/lib/src/commands/daemon.dart
@@ -119,6 +119,8 @@
   DeviceDomain deviceDomain;
   EmulatorDomain emulatorDomain;
   StreamSubscription<Map<String, dynamic>> _commandSubscription;
+  int _outgoingRequestId = 1;
+  final Map<String, Completer<dynamic>> _outgoingRequestCompleters = <String, Completer<dynamic>>{};
 
   final DispatchCommand sendCommand;
   final NotifyingLogger notifyingLogger;
@@ -147,17 +149,32 @@
 
     try {
       final String method = request['method'] as String;
-      if (!method.contains('.')) {
-        throw 'method not understood: $method';
-      }
+      if (method != null) {
+        if (!method.contains('.')) {
+          throw 'method not understood: $method';
+        }
 
-      final String prefix = method.substring(0, method.indexOf('.'));
-      final String name = method.substring(method.indexOf('.') + 1);
-      if (_domainMap[prefix] == null) {
-        throw 'no domain for method: $method';
-      }
+        final String prefix = method.substring(0, method.indexOf('.'));
+        final String name = method.substring(method.indexOf('.') + 1);
+        if (_domainMap[prefix] == null) {
+          throw 'no domain for method: $method';
+        }
 
-      _domainMap[prefix].handleCommand(name, id, castStringKeyedMap(request['params']) ?? const <String, dynamic>{});
+        _domainMap[prefix].handleCommand(name, id, castStringKeyedMap(request['params']) ?? const <String, dynamic>{});
+      } else {
+        // If there was no 'method' field then it's a response to a daemon-to-editor request.
+        final Completer<dynamic> completer = _outgoingRequestCompleters[id.toString()];
+        if (completer == null) {
+          throw 'unexpected response with id: $id';
+        }
+        _outgoingRequestCompleters.remove(id.toString());
+
+        if (request['error'] != null) {
+          completer.completeError(request['error']);
+        } else {
+          completer.complete(request['result']);
+        }
+      }
     } catch (error, trace) {
       _send(<String, dynamic>{
         'id': id,
@@ -167,6 +184,22 @@
     }
   }
 
+  Future<dynamic> sendRequest(String method, [ dynamic args ]) {
+    final Map<String, dynamic> map = <String, dynamic>{'method': method};
+    if (args != null) {
+      map['params'] = _toJsonable(args);
+    }
+
+    final int id = _outgoingRequestId++;
+    final Completer<dynamic> completer = Completer<dynamic>();
+
+    map['id'] = id.toString();
+    _outgoingRequestCompleters[id.toString()] = completer;
+
+    _send(map);
+    return completer.future;
+  }
+
   void _send(Map<String, dynamic> map) => sendCommand(map);
 
   void shutdown({ dynamic error }) {
@@ -187,6 +220,7 @@
 abstract class Domain {
   Domain(this.daemon, this.name);
 
+
   final Daemon daemon;
   final String name;
   final Map<String, CommandHandler> _handlers = <String, CommandHandler>{};
@@ -317,6 +351,21 @@
     return Future<String>.value(protocolVersion);
   }
 
+  /// Sends a request back to the client asking it to expose/tunnel a URL.
+  ///
+  /// This method should only be called if the client opted-in with the
+  /// --web-allow-expose-url switch. The client may return the same URL back if
+  /// tunnelling is not required for a given URL.
+  Future<String> exposeUrl(String url) async {
+    final dynamic res = await daemon.sendRequest('app.exposeUrl', <String, String>{'url': url});
+    if (res is Map<String, dynamic> && res['url'] is String) {
+      return res['url'] as String;
+    } else {
+      printError('Invalid response to exposeUrl - params should include a String url field');
+      return url;
+    }
+  }
+
   Future<void> shutdown(Map<String, dynamic> args) {
     Timer.run(daemon.shutdown);
     return Future<void>.value();
@@ -448,6 +497,7 @@
         ipv6: ipv6,
         stayResident: true,
         dartDefines: daemon.dartDefines,
+        urlTunneller: options.webEnableExposeUrl ? daemon.daemonDomain.exposeUrl : null,
       );
     } else if (enableHotReload) {
       runner = HotRunner(
diff --git a/packages/flutter_tools/lib/src/commands/run.dart b/packages/flutter_tools/lib/src/commands/run.dart
index 222f207..f854a92 100644
--- a/packages/flutter_tools/lib/src/commands/run.dart
+++ b/packages/flutter_tools/lib/src/commands/run.dart
@@ -314,6 +314,7 @@
         initializePlatform: boolArg('web-initialize-platform'),
         hostname: featureFlags.isWebEnabled ? stringArg('web-hostname') : '',
         port: featureFlags.isWebEnabled ? stringArg('web-port') : '',
+        webEnableExposeUrl: featureFlags.isWebEnabled && boolArg('web-allow-expose-url'),
       );
     } else {
       return DebuggingOptions.enabled(
@@ -334,6 +335,7 @@
         initializePlatform: boolArg('web-initialize-platform'),
         hostname: featureFlags.isWebEnabled ? stringArg('web-hostname') : '',
         port: featureFlags.isWebEnabled ? stringArg('web-port') : '',
+        webEnableExposeUrl: featureFlags.isWebEnabled && boolArg('web-allow-expose-url'),
         vmserviceOutFile: stringArg('vmservice-out-file'),
         // Allow forcing fast-start to off to prevent doing more work on devices that
         // don't support it.
@@ -489,6 +491,7 @@
         debuggingOptions: _createDebuggingOptions(),
         stayResident: stayResident,
         dartDefines: dartDefines,
+        urlTunneller: null,
       );
     } else {
       runner = ColdRunner(
diff --git a/packages/flutter_tools/lib/src/device.dart b/packages/flutter_tools/lib/src/device.dart
index b335d3e..452d471 100644
--- a/packages/flutter_tools/lib/src/device.dart
+++ b/packages/flutter_tools/lib/src/device.dart
@@ -536,12 +536,18 @@
     this.initializePlatform = true,
     this.hostname,
     this.port,
+    this.webEnableExposeUrl,
     this.vmserviceOutFile,
     this.fastStart = false,
    }) : debuggingEnabled = true;
 
-  DebuggingOptions.disabled(this.buildInfo, { this.initializePlatform = true, this.port, this.hostname, this.cacheSkSL = false, })
-    : debuggingEnabled = false,
+  DebuggingOptions.disabled(this.buildInfo, {
+      this.initializePlatform = true,
+      this.port,
+      this.hostname,
+      this.webEnableExposeUrl,
+      this.cacheSkSL = false,
+    }) : debuggingEnabled = false,
       useTestFonts = false,
       startPaused = false,
       dartFlags = '',
@@ -577,6 +583,7 @@
   final int deviceVmServicePort;
   final String port;
   final String hostname;
+  final bool webEnableExposeUrl;
   /// A file where the vmservice URL should be written after the application is started.
   final String vmserviceOutFile;
   final bool fastStart;
diff --git a/packages/flutter_tools/lib/src/runner/flutter_command.dart b/packages/flutter_tools/lib/src/runner/flutter_command.dart
index 42905da..b9a6d91 100644
--- a/packages/flutter_tools/lib/src/runner/flutter_command.dart
+++ b/packages/flutter_tools/lib/src/runner/flutter_command.dart
@@ -150,6 +150,12 @@
         'will select a random open port on the host.',
       hide: hide,
     );
+    argParser.addFlag('web-allow-expose-url',
+      defaultsTo: false,
+      help: 'Enables daemon-to-editor requests (app.exposeUrl) for exposing URLs '
+        'when running on remote machines.',
+      hide: hide,
+    );
   }
 
   void usesTargetOption() {
diff --git a/packages/flutter_tools/lib/src/web/web_runner.dart b/packages/flutter_tools/lib/src/web/web_runner.dart
index f46258e..94f2480 100644
--- a/packages/flutter_tools/lib/src/web/web_runner.dart
+++ b/packages/flutter_tools/lib/src/web/web_runner.dart
@@ -5,6 +5,7 @@
 import 'package:meta/meta.dart';
 
 import '../base/context.dart';
+import '../base/net.dart';
 import '../device.dart';
 import '../project.dart';
 import '../resident_runner.dart';
@@ -24,5 +25,6 @@
     @required bool ipv6,
     @required DebuggingOptions debuggingOptions,
     @required List<String> dartDefines,
+    @required UrlTunneller urlTunneller,
   });
 }
diff --git a/packages/flutter_tools/test/commands.shard/hermetic/build_web_test.dart b/packages/flutter_tools/test/commands.shard/hermetic/build_web_test.dart
index 4540b20..00b693d 100644
--- a/packages/flutter_tools/test/commands.shard/hermetic/build_web_test.dart
+++ b/packages/flutter_tools/test/commands.shard/hermetic/build_web_test.dart
@@ -71,6 +71,7 @@
       debuggingOptions: DebuggingOptions.enabled(BuildInfo.debug),
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
     expect(await runner.run(), 1);
   }));
diff --git a/packages/flutter_tools/test/commands.shard/hermetic/daemon_test.dart b/packages/flutter_tools/test/commands.shard/hermetic/daemon_test.dart
index 88863bd..04478fa 100644
--- a/packages/flutter_tools/test/commands.shard/hermetic/daemon_test.dart
+++ b/packages/flutter_tools/test/commands.shard/hermetic/daemon_test.dart
@@ -12,6 +12,7 @@
 import 'package:flutter_tools/src/globals.dart';
 import 'package:flutter_tools/src/ios/ios_workflow.dart';
 import 'package:flutter_tools/src/resident_runner.dart';
+import 'package:pedantic/pedantic.dart';
 
 import '../../src/common.dart';
 import '../../src/context.dart';
@@ -279,6 +280,35 @@
       await responses.close();
       await commands.close();
     });
+
+    testUsingContext('daemon can send exposeUrl requests to the client', () async {
+      const String originalUrl = 'http://localhost:1234/';
+      const String mappedUrl = 'https://publichost:4321/';
+      final StreamController<Map<String, dynamic>> input = StreamController<Map<String, dynamic>>();
+      final StreamController<Map<String, dynamic>> output = StreamController<Map<String, dynamic>>();
+
+      daemon = Daemon(
+        input.stream,
+        output.add,
+        notifyingLogger: notifyingLogger,
+        dartDefines: const <String>[],
+      );
+
+      // Respond to any requests from the daemon to expose a URL.
+      unawaited(output.stream
+        .firstWhere((Map<String, dynamic> request) => request['method'] == 'app.exposeUrl')
+        .then((Map<String, dynamic> request) {
+          expect(request['params']['url'], equals(originalUrl));
+          input.add(<String, dynamic>{'id': request['id'], 'result': <String, dynamic>{'url': mappedUrl}});
+        })
+      );
+
+      final String exposedUrl = await daemon.daemonDomain.exposeUrl(originalUrl);
+      expect(exposedUrl, equals(mappedUrl));
+
+      await output.close();
+      await input.close();
+    });
   });
 
   group('daemon serialization', () {
diff --git a/packages/flutter_tools/test/commands.shard/hermetic/run_test.dart b/packages/flutter_tools/test/commands.shard/hermetic/run_test.dart
index fad57ed..83d98db 100644
--- a/packages/flutter_tools/test/commands.shard/hermetic/run_test.dart
+++ b/packages/flutter_tools/test/commands.shard/hermetic/run_test.dart
@@ -14,6 +14,7 @@
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/user_messages.dart';
+import 'package:flutter_tools/src/base/net.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/run.dart';
@@ -629,6 +630,7 @@
     bool ipv6,
     DebuggingOptions debuggingOptions,
     List<String> dartDefines,
+    UrlTunneller urlTunneller,
   }) {
     _dartDefines = dartDefines;
     return MockWebRunner();
diff --git a/packages/flutter_tools/test/general.shard/resident_web_runner_cold_test.dart b/packages/flutter_tools/test/general.shard/resident_web_runner_cold_test.dart
index 9ea8e51..ebf2127 100644
--- a/packages/flutter_tools/test/general.shard/resident_web_runner_cold_test.dart
+++ b/packages/flutter_tools/test/general.shard/resident_web_runner_cold_test.dart
@@ -8,6 +8,7 @@
 import 'package:flutter_tools/src/base/common.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/base/net.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/globals.dart';
@@ -35,13 +36,14 @@
     when(mockFlutterDevice.device).thenReturn(mockWebDevice);
     testbed = Testbed(
       setup: () {
-        residentWebRunner =  residentWebRunner = DwdsWebRunnerFactory().createWebRunner(
+        residentWebRunner = residentWebRunner = DwdsWebRunnerFactory().createWebRunner(
           mockFlutterDevice,
           flutterProject: FlutterProject.current(),
           debuggingOptions: DebuggingOptions.disabled(BuildInfo.release),
           ipv6: true,
           stayResident: true,
           dartDefines: const <String>[],
+          urlTunneller: null,
         ) as ResidentWebRunner;
       },
       overrides: <Type, Generator>{
@@ -53,6 +55,7 @@
           @required bool initializePlatform,
           @required String hostname,
           @required String port,
+          @required UrlTunneller urlTunneller,
           @required List<String> dartDefines,
         }) async {
           return mockWebFs;
diff --git a/packages/flutter_tools/test/general.shard/resident_web_runner_test.dart b/packages/flutter_tools/test/general.shard/resident_web_runner_test.dart
index 6cac16d..3977fdf 100644
--- a/packages/flutter_tools/test/general.shard/resident_web_runner_test.dart
+++ b/packages/flutter_tools/test/general.shard/resident_web_runner_test.dart
@@ -11,6 +11,7 @@
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/base/net.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_runner/resident_web_runner.dart';
 import 'package:flutter_tools/src/build_runner/web_fs.dart';
@@ -78,6 +79,7 @@
           ipv6: true,
           stayResident: true,
           dartDefines: const <String>[],
+          urlTunneller: null,
         ) as ResidentWebRunner;
       },
       overrides: <Type, Generator>{
@@ -90,6 +92,7 @@
           @required String hostname,
           @required String port,
           @required List<String> dartDefines,
+          @required UrlTunneller urlTunneller,
         }) async {
           didSkipDwds = skipDwds;
           return mockWebFs;
@@ -142,6 +145,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
 
     expect(profileResidentWebRunner.debuggingEnabled, false);
@@ -172,6 +176,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: <String>[],
+      urlTunneller: null,
     );
 
     expect(profileResidentWebRunner.debuggingEnabled, true);
@@ -187,6 +192,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
 
     final Completer<DebugConnectionInfo> connectionInfoCompleter = Completer<DebugConnectionInfo>();
@@ -210,6 +216,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     );
 
     expect(profileResidentWebRunner.supportsServiceProtocol, false);
@@ -263,6 +270,7 @@
       ipv6: true,
       stayResident: false,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
 
     expect(await residentWebRunner.run(), 0);
@@ -299,6 +307,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
     _setupMocks();
     final Completer<DebugConnectionInfo> connectionInfoCompleter = Completer<DebugConnectionInfo>();
@@ -513,6 +522,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
 
     expect(residentWebRunner.runtimeType.toString(), '_DwdsResidentWebRunner');
@@ -830,6 +840,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
 
     final Completer<DebugConnectionInfo> connectionInfoCompleter = Completer<DebugConnectionInfo>();
@@ -865,6 +876,7 @@
       ipv6: true,
       stayResident: true,
       dartDefines: const <String>[],
+      urlTunneller: null,
     ) as ResidentWebRunner;
 
     final Completer<DebugConnectionInfo> connectionInfoCompleter = Completer<DebugConnectionInfo>();
diff --git a/packages/flutter_tools/test/general.shard/web/web_fs_test.dart b/packages/flutter_tools/test/general.shard/web/web_fs_test.dart
index 98ce59a..dd372e3 100644
--- a/packages/flutter_tools/test/general.shard/web/web_fs_test.dart
+++ b/packages/flutter_tools/test/general.shard/web/web_fs_test.dart
@@ -109,6 +109,7 @@
           LogWriter logWriter,
           bool verbose,
           bool enableDebugExtension,
+          UrlEncoder urlEncoder,
         }) async {
           return mockDwds;
         },
@@ -126,6 +127,7 @@
       initializePlatform: true,
       hostname: null,
       port: null,
+      urlTunneller: null,
       dartDefines: const <String>[],
     );
     // Since the .packages file is missing in the memory filesystem, this should
@@ -156,6 +158,7 @@
       initializePlatform: false,
       hostname: null,
       port: null,
+      urlTunneller: null,
       dartDefines: const <String>[],
     );
 
@@ -177,6 +180,7 @@
       initializePlatform: false,
       hostname: 'foo',
       port: '1234',
+      urlTunneller: null,
       dartDefines: const <String>[],
     );
 
@@ -210,6 +214,7 @@
       initializePlatform: false,
       hostname: 'foo',
       port: '1234',
+      urlTunneller: null,
       dartDefines: const <String>[],
     ), throwsA(isInstanceOf<Exception>()));
   }));