dart2js: Use js('source') instead of js['source'] to invoke JS mini-parser

tests/compiler/dart2js/js_parser_test.dart

Index: tests/compiler/dart2js/js_parser_test.dart
diff --git a/tests/compiler/dart2js/js_parser_test.dart b/tests/compiler/dart2js/js_parser_test.dart
index 3bd655978e08bcd0ac77a84c299d5ca74e971370..b192ec8d2f2c1fc6929e97f96bcefb918f5b049e 100644
--- a/tests/compiler/dart2js/js_parser_test.dart
+++ b/tests/compiler/dart2js/js_parser_test.dart
@@ -7,7 +7,7 @@ import '../../../sdk/lib/_internal/compiler/implementation/js/js.dart' as jsAst;
 import '../../../sdk/lib/_internal/compiler/implementation/js/js.dart' show js;
 
 void testExpression(String expression, [String expect = ""]) {
-  jsAst.Node node = js[expression];
+  jsAst.Node node = js(expression);
   MockCompiler compiler = new MockCompiler();
   String jsText =
       jsAst.prettyPrint(node,
@@ -25,7 +25,7 @@ void testError(String expression, [String expect = ""]) {
     Expect.isTrue(exception.toString().contains(expect));
     return true;
   }
-  Expect.throws(() => js[expression], doCheck);
+  Expect.throws(() => js(expression), doCheck);
 }