fixes #146, JS globals were not understood by the renamer

lib/src/js/printer.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of js_ast;
 
 
 class JavaScriptPrintingOptions {
   final bool shouldCompressOutput;
   final bool minifyLocalVariables;
@@ skipping 1367 matching lines @@
         codes.add(nthLetter((n ~/ nameSpaceSize) % LETTERS));
       }
       codes.add(charCodes.$0 + digit);
       newName = new String.fromCharCodes(codes);
     }
     assert(new RegExp(r'[a-zA-Z][a-zA-Z0-9]*').hasMatch(newName));
     maps.last[oldName] = newName;
     return newName;
   }
 }
+
+/// Like [BaseVisitor], but calls [declare] for [Identifier] declarations, and
+/// [visitIdentifier] otherwise.
+abstract class VariableDeclarationVisitor<T> extends BaseVisitor<T> {
+  declare(Identifier node);
+
+  visitFunctionExpression(FunctionExpression node) {
+    for (Identifier param in node.params) declare(param);
+    node.body.accept(this);
+  }
+
+  visitVariableInitialization(VariableInitialization node) {
+    declare(node.declaration);
+    if (node.value != null) node.value.accept(this);
+  }
+
+  visitCatch(Catch node) {
+    declare(node.declaration);
+    node.body.accept(this);
+  }
+
+  visitFunctionDeclaration(FunctionDeclaration node) {
+    declare(node.name);
+    node.function.accept(this);
+  }
+
+  visitNamedFunction(NamedFunction node) {
+    declare(node.name);
+    node.function.accept(this);
+  }
+
+  visitClassExpression(ClassExpression node) {
+    declare(node.name);
+    if (node.heritage != null) node.heritage.accept(this);
+    for (Method element in node.methods) element.accept(this);
+  }
+}