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

sdk/lib/_internal/compiler/implementation/js/nodes.dart

Index: sdk/lib/_internal/compiler/implementation/js/nodes.dart
diff --git a/sdk/lib/_internal/compiler/implementation/js/nodes.dart b/sdk/lib/_internal/compiler/implementation/js/nodes.dart
index 6f0b755a3eb15201c493d91401d6b39051f4ee82..bd85713e452e64077b0bc0b142b25b84574b659b 100644
--- a/sdk/lib/_internal/compiler/implementation/js/nodes.dart
+++ b/sdk/lib/_internal/compiler/implementation/js/nodes.dart
@@ -465,9 +465,9 @@ abstract class Expression extends Node {
     if (expression == null) {
       arguments = <Expression>[];
     } else if (expression is List) {
-      arguments = expression.map(js.toExpression).toList();
+      arguments = expression.map(jsBuilder.toExpression).toList();
     } else {
-      arguments = <Expression>[js.toExpression(expression)];
+      arguments = <Expression>[jsBuilder.toExpression(expression)];
     }
     return callWith(arguments);
   }
@@ -491,15 +491,16 @@ abstract class Expression extends Node {
   Expression operator >=(expression) => binary('>=', expression);
 
   Expression binary(String operator, expression) {
-    return new Binary(operator, this, js.toExpression(expression));
+    return new Binary(operator, this, jsBuilder.toExpression(expression));
   }
 
   Expression assign(expression) {
-    return new Assignment(this, js.toExpression(expression));
+    return new Assignment(this, jsBuilder.toExpression(expression));
   }
 
   Expression update(String operator, expression) {
-    return new Assignment.compound(this, operator, js.toExpression(expression));
+    return new Assignment.compound(
+        this, operator, jsBuilder.toExpression(expression));
   }
 
   Expression get plusPlus => new Postfix('++', this);