Emit classes using ASTs

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 d55b6a4cea790e1445e58afa0a198294f6de970c..fa7722e75ab2bf5c1e6242d4b4567f358958104d 100644
--- a/sdk/lib/_internal/compiler/implementation/js/nodes.dart
+++ b/sdk/lib/_internal/compiler/implementation/js/nodes.dart
@@ -864,7 +864,7 @@ Binary equals(Expression left, Expression right) {
   return new Binary('==', left, right);
 }
 
-LiteralString string(String value) => new LiteralString("'$value'");
+LiteralString string(String value) => new LiteralString('"$value"');
 
 If if_(Expression condition, Node then, [Node otherwise]) {
   return (otherwise == null)
@@ -882,6 +882,10 @@ PropertyAccess fieldAccess(Expression receiver, String fieldName) {
 
 Block emptyBlock() => new Block.empty();
 
+Block block1(Statement statement) => new Block(<Statement>[statement]);
+
+Block block2(Statement s1, Statement s2) => new Block(<Statement>[s1, s2]);
+
 Call call(Expression target, List<Expression> arguments) {
   return new Call(target, arguments);
 }