Configure polymer transformers based on whether pub is running the build or

pkg/polymer/lib/transformer.dart

Index: pkg/polymer/lib/transformer.dart
diff --git a/pkg/polymer/lib/transformer.dart b/pkg/polymer/lib/transformer.dart
index 9bbd366256837fac7e68120c54f5befba117f91b..b9649badcef527193f3585d10ef8f192285f73d9 100644
--- a/pkg/polymer/lib/transformer.dart
+++ b/pkg/polymer/lib/transformer.dart
@@ -35,11 +35,14 @@ class PolymerTransformerGroup implements TransformerGroup {
 }
 
 TransformOptions _parseSettings(BarbackSettings settings) {
-  var args = settings.transformer;
+  var args = settings.configuration;
+  bool release = settings.mode == BarbackMode.RELEASE;
+  bool jsOption = args['js'];
+  bool csp = args['csp'] == true; // defaults to false
   return new TransformOptions(
       entryPoints: _readEntrypoints(args['entry_points']),
-      directlyIncludeJS: args['js'] != false, // default to true
-      contentSecurityPolicy: args['csp'] == true); // default to false
+      directlyIncludeJS: jsOption == null ? release : jsOption,
+      contentSecurityPolicy: csp);
 }
 
 _readEntrypoints(value) {