Dart2js option to dump info about compilation

sdk/lib/_internal/compiler/implementation/scanner/class_element_parser.dart

 // Copyright (c) 2011, 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 scanner;
 
 class ClassElementParser extends PartialParser {
   ClassElementParser(Listener listener) : super(listener);
 
   Token parseClassBody(Token token) => fullParseClassBody(token);
@@ skipping 147 matching lines @@
     addMember(memberElement);
   }
 
   void endFields(int count, Token beginToken, Token endToken) {
     super.endFields(count, beginToken, endToken);
     VariableDefinitions variableDefinitions = popNode();
     Modifiers modifiers = variableDefinitions.modifiers;
     pushNode(null);
     void buildFieldElement(String name, Element fields) {
       Element element =
-          new VariableElementX(name, fields, ElementKind.FIELD, null);
+          new FieldElementX(name, fields, null);
       addMember(element);
     }
     buildFieldElements(modifiers, variableDefinitions.definitions,
                        enclosingElement,
                        buildFieldElement, beginToken, endToken);
   }
 
   void endInitializer(Token assignmentOperator) {
     pushNode(null); // Super expects an expression, but
                     // ClassElementParser just skips expressions.
@@ skipping 14 matching lines @@
 
   void endMetadata(Token beginToken, Token periodBeforeName, Token endToken) {
     popNode(); // Discard arguments.
     if (periodBeforeName != null) {
       popNode(); // Discard name.
     }
     popNode(); // Discard node (Send or Identifier).
     pushMetadata(new PartialMetadataAnnotation(beginToken, endToken));
   }
 }