Make some utility methods private (#1747)

These methods are not used outside of the library they are defined in.
diff --git a/pkgs/test/lib/src/runner/browser/dom.dart b/pkgs/test/lib/src/runner/browser/dom.dart
index af003c9..be27d04 100644
--- a/pkgs/test/lib/src/runner/browser/dom.dart
+++ b/pkgs/test/lib/src/runner/browser/dom.dart
@@ -203,7 +203,7 @@
 }
 
 WebSocket createWebSocket(String url) =>
-    callConstructorString('WebSocket', <Object>[url])! as WebSocket;
+    _callConstructor('WebSocket', <Object>[url])! as WebSocket;
 
 @JS()
 @staticInterop
@@ -215,13 +215,13 @@
 }
 
 MessageChannel createMessageChannel() =>
-    callConstructorString('MessageChannel', <Object>[])! as MessageChannel;
+    _callConstructor('MessageChannel', <Object>[])! as MessageChannel;
 
-Object? getConstructor(String constructorName) =>
+Object? _findConstructor(String constructorName) =>
     js_util.getProperty(window, constructorName);
 
-Object? callConstructorString(String constructorName, List<Object?> args) {
-  final Object? constructor = getConstructor(constructorName);
+Object? _callConstructor(String constructorName, List<Object?> args) {
+  final Object? constructor = _findConstructor(constructorName);
   if (constructor == null) {
     return null;
   }
diff --git a/pkgs/test/lib/src/runner/browser/static/host.dart.js b/pkgs/test/lib/src/runner/browser/static/host.dart.js
index 223bef2..2966489 100644
--- a/pkgs/test/lib/src/runner/browser/static/host.dart.js
+++ b/pkgs/test/lib/src/runner/browser/static/host.dart.js
@@ -1,4 +1,4 @@
-// Generated by dart2js (NullSafetyMode.sound, csp), the Dart to JavaScript compiler version: 2.18.0-edge.bd660d98472f01c57ece4dcf2a7a8810ea4e402d.
+// Generated by dart2js (NullSafetyMode.sound, csp, deferred-serialization), the Dart to JavaScript compiler version: 2.19.0-36.0.dev.
 // The code supports the following hooks:
 // dartPrint(message):
 //    if this function is defined it is called instead of the Dart [print]
@@ -5794,7 +5794,7 @@
         }
     },
     _createTables() {
-      var _i, t1, t2, t3, t4, t5,
+      var _i, t1, t2, t3, t4, b,
         _s77_ = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-._~!$&'()*+,;=",
         _s1_ = ".", _s1_0 = ":", _s1_1 = "/", _s1_2 = "?", _s1_3 = "#",
         tables = A._setArrayType(new Array(22), type$.JSArray_Uint8List);
@@ -5803,127 +5803,126 @@
       t1 = new A._createTables_build(tables);
       t2 = new A._createTables_setChars();
       t3 = new A._createTables_setRange();
-      t4 = type$.Uint8List;
-      t5 = t4._as(t1.call$2(0, 225));
-      t2.call$3(t5, _s77_, 1);
-      t2.call$3(t5, _s1_, 14);
-      t2.call$3(t5, _s1_0, 34);
-      t2.call$3(t5, _s1_1, 3);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(14, 225));
-      t2.call$3(t5, _s77_, 1);
-      t2.call$3(t5, _s1_, 15);
-      t2.call$3(t5, _s1_0, 34);
-      t2.call$3(t5, _s1_1, 234);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(15, 225));
-      t2.call$3(t5, _s77_, 1);
-      t2.call$3(t5, "%", 225);
-      t2.call$3(t5, _s1_0, 34);
-      t2.call$3(t5, _s1_1, 9);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(1, 225));
-      t2.call$3(t5, _s77_, 1);
-      t2.call$3(t5, _s1_0, 34);
-      t2.call$3(t5, _s1_1, 10);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(2, 235));
-      t2.call$3(t5, _s77_, 139);
-      t2.call$3(t5, _s1_1, 131);
-      t2.call$3(t5, _s1_, 146);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(3, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_1, 68);
-      t2.call$3(t5, _s1_, 18);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(4, 229));
-      t2.call$3(t5, _s77_, 5);
-      t3.call$3(t5, "AZ", 229);
-      t2.call$3(t5, _s1_0, 102);
-      t2.call$3(t5, "@", 68);
-      t2.call$3(t5, "[", 232);
-      t2.call$3(t5, _s1_1, 138);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(5, 229));
-      t2.call$3(t5, _s77_, 5);
-      t3.call$3(t5, "AZ", 229);
-      t2.call$3(t5, _s1_0, 102);
-      t2.call$3(t5, "@", 68);
-      t2.call$3(t5, _s1_1, 138);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(6, 231));
-      t3.call$3(t5, "19", 7);
-      t2.call$3(t5, "@", 68);
-      t2.call$3(t5, _s1_1, 138);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(7, 231));
-      t3.call$3(t5, "09", 7);
-      t2.call$3(t5, "@", 68);
-      t2.call$3(t5, _s1_1, 138);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t2.call$3(t4._as(t1.call$2(8, 8)), "]", 5);
-      t5 = t4._as(t1.call$2(9, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_, 16);
-      t2.call$3(t5, _s1_1, 234);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(16, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_, 17);
-      t2.call$3(t5, _s1_1, 234);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(17, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_1, 9);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(10, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_, 18);
-      t2.call$3(t5, _s1_1, 234);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(18, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_, 19);
-      t2.call$3(t5, _s1_1, 234);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(19, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_1, 234);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(11, 235));
-      t2.call$3(t5, _s77_, 11);
-      t2.call$3(t5, _s1_1, 10);
-      t2.call$3(t5, _s1_2, 172);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(12, 236));
-      t2.call$3(t5, _s77_, 12);
-      t2.call$3(t5, _s1_2, 12);
-      t2.call$3(t5, _s1_3, 205);
-      t5 = t4._as(t1.call$2(13, 237));
-      t2.call$3(t5, _s77_, 13);
-      t2.call$3(t5, _s1_2, 13);
-      t3.call$3(t4._as(t1.call$2(20, 245)), "az", 21);
-      t1 = t4._as(t1.call$2(21, 245));
-      t3.call$3(t1, "az", 21);
-      t3.call$3(t1, "09", 21);
-      t2.call$3(t1, "+-.", 21);
+      t4 = type$.Uint8List._as(t1.call$2(0, 225));
+      t2.call$3(t4, _s77_, 1);
+      t2.call$3(t4, _s1_, 14);
+      t2.call$3(t4, _s1_0, 34);
+      t2.call$3(t4, _s1_1, 3);
+      t2.call$3(t4, _s1_2, 172);
+      t2.call$3(t4, _s1_3, 205);
+      b = t1.call$2(14, 225);
+      t2.call$3(b, _s77_, 1);
+      t2.call$3(b, _s1_, 15);
+      t2.call$3(b, _s1_0, 34);
+      t2.call$3(b, _s1_1, 234);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(15, 225);
+      t2.call$3(b, _s77_, 1);
+      t2.call$3(b, "%", 225);
+      t2.call$3(b, _s1_0, 34);
+      t2.call$3(b, _s1_1, 9);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(1, 225);
+      t2.call$3(b, _s77_, 1);
+      t2.call$3(b, _s1_0, 34);
+      t2.call$3(b, _s1_1, 10);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(2, 235);
+      t2.call$3(b, _s77_, 139);
+      t2.call$3(b, _s1_1, 131);
+      t2.call$3(b, _s1_, 146);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(3, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_1, 68);
+      t2.call$3(b, _s1_, 18);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(4, 229);
+      t2.call$3(b, _s77_, 5);
+      t3.call$3(b, "AZ", 229);
+      t2.call$3(b, _s1_0, 102);
+      t2.call$3(b, "@", 68);
+      t2.call$3(b, "[", 232);
+      t2.call$3(b, _s1_1, 138);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(5, 229);
+      t2.call$3(b, _s77_, 5);
+      t3.call$3(b, "AZ", 229);
+      t2.call$3(b, _s1_0, 102);
+      t2.call$3(b, "@", 68);
+      t2.call$3(b, _s1_1, 138);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(6, 231);
+      t3.call$3(b, "19", 7);
+      t2.call$3(b, "@", 68);
+      t2.call$3(b, _s1_1, 138);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(7, 231);
+      t3.call$3(b, "09", 7);
+      t2.call$3(b, "@", 68);
+      t2.call$3(b, _s1_1, 138);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      t2.call$3(t1.call$2(8, 8), "]", 5);
+      b = t1.call$2(9, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_, 16);
+      t2.call$3(b, _s1_1, 234);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(16, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_, 17);
+      t2.call$3(b, _s1_1, 234);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(17, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_1, 9);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(10, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_, 18);
+      t2.call$3(b, _s1_1, 234);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(18, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_, 19);
+      t2.call$3(b, _s1_1, 234);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(19, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_1, 234);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(11, 235);
+      t2.call$3(b, _s77_, 11);
+      t2.call$3(b, _s1_1, 10);
+      t2.call$3(b, _s1_2, 172);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(12, 236);
+      t2.call$3(b, _s77_, 12);
+      t2.call$3(b, _s1_2, 12);
+      t2.call$3(b, _s1_3, 205);
+      b = t1.call$2(13, 237);
+      t2.call$3(b, _s77_, 13);
+      t2.call$3(b, _s1_2, 13);
+      t3.call$3(t1.call$2(20, 245), "az", 21);
+      b = t1.call$2(21, 245);
+      t3.call$3(b, "az", 21);
+      t3.call$3(b, "09", 21);
+      t2.call$3(b, "+-.", 21);
       return tables;
     },
     _scan(uri, start, end, state, indices) {
@@ -6928,7 +6927,7 @@
       var t1 = A._setArrayType([type, listener], type$.JSArray_Object);
       A.callMethod(_this, "addEventListener", t1, type$.dynamic);
     },
-    callConstructorString(constructorName, args) {
+    _callConstructor(constructorName, args) {
       var $constructor = self.window[constructorName];
       if ($constructor == null)
         return null;
@@ -6993,7 +6992,7 @@
       var t2, controller, t3,
         t1 = $.$get$_currentUrl().get$queryParameters().$index(0, "managerUrl");
       t1.toString;
-      t1 = A.callConstructorString("WebSocket", A._setArrayType([t1], type$.JSArray_Object));
+      t1 = A._callConstructor("WebSocket", A._setArrayType([t1], type$.JSArray_Object));
       t1.toString;
       type$.JavaScriptObject._as(t1);
       t2 = type$.dynamic;
@@ -7019,7 +7018,7 @@
       $._iframes.$indexSet(0, id, iframe);
       iframe.src = url;
       t5._as(type$.nullable_JavaScriptObject._as(self.document.body).appendChild(iframe));
-      t2 = A.callConstructorString("MessageChannel", A._setArrayType([], t2));
+      t2 = A._callConstructor("MessageChannel", A._setArrayType([], t2));
       t2.toString;
       t5._as(t2);
       controller = A.StreamChannelController$(true, t4);