Fix for listening to custom streams in DWDS. (#2011)

Author: Daniel Chevalier

dwds/lib/src/services/chrome_proxy_service.dart

@@ -707,7 +707,7 @@ ${globalLoadStrategy.loadModuleSnippet}("dart_sdk").developer.invokeExtension(
         default:
           throw RPCError(
             'streamListen',
-            RPCError.kMethodNotFound,
+            RPCError.kInvalidParams,
             'The stream `$streamId` is not supported on web devices',
           );
       }

dwds/test/chrome_proxy_service_test.dart

@@ -2019,6 +2019,13 @@ void main() {
                 e.kind == EventKind.kVMUpdate && e.vm!.name == 'test')));
         await service.setVMName('test');
       });
+
+      test('custom stream', () {
+        expect(
+            () => service.streamListen('aCustomStreamId'),
+            throwsA(predicate(
+                (e) => (e is RPCError) && e.code == RPCError.kInvalidParams)));
+      });
     });
 
     test('Logging', () async {