Build fixes: adds arguments to the pub-build plugin to configure whether 'js'

pkg/polymer/lib/src/build/script_compactor.dart

Index: pkg/polymer/lib/src/build/script_compactor.dart
diff --git a/pkg/polymer/lib/src/build/script_compactor.dart b/pkg/polymer/lib/src/build/script_compactor.dart
index 01885f747dbc39b1db97626d57423240499f0ee8..8ac8fd0d1dbd0b67d033e59ddd27eb119f9fc1c0 100644
--- a/pkg/polymer/lib/src/build/script_compactor.dart
+++ b/pkg/polymer/lib/src/build/script_compactor.dart
@@ -81,7 +81,10 @@ class ScriptCompactor extends Transformer with PolymerTransformer {
         mainScriptTag.attributes['src'] = 
             path.url.basename(bootstrapId.path);
 
-        libraries.add(mainLibraryId);
+        // TODO(sigmund): stop renaming the file (see dartbug.com/14554)
+        var modifiedMainId = mainLibraryId.addExtension('_modified.dart');
+
+        libraries.add(modifiedMainId);
         var urls = libraries.map((id) => assetUrlFor(id, bootstrapId, logger))
             .where((url) => url != null).toList();
         var buffer = new StringBuffer()..writeln(MAIN_HEADER);
@@ -95,12 +98,17 @@ class ScriptCompactor extends Transformer with PolymerTransformer {
             ..writeln('  configureForDeployment([')
             ..writeAll(urls.map((url) => "      '$url',\n"))
             ..writeln('    ]);')
-            ..writeln('  i${i - 1}.main();')
+            ..writeln('  i${i - 1}.polymerMainWrapper();')
             ..writeln('}');
 
         transform.addOutput(new Asset.fromString(
               bootstrapId, buffer.toString()));
         transform.addOutput(new Asset.fromString(id, document.outerHtml));
+
+        return transform.readInputAsString(mainLibraryId).then((contents) {
+          transform.addOutput(new Asset.fromString(modifiedMainId,
+              '$contents\n\npolymerMainWrapper() => main();\n'));
+        });
       });
     });
   }