Support parsing of enums in dart2js.

sdk/lib/_internal/compiler/implementation/scanner/parser.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 scanner;
 
 class FormalParameterType {
   final String type;
   const FormalParameterType(this.type);
   bool get isRequired => this == REQUIRED;
@@ skipping 44 matching lines @@
     listener.endCompilationUnit(count, token);
     return token;
   }
 
   Token parseTopLevelDeclaration(Token token) {
     token = parseMetadataStar(token);
     final String value = token.stringValue;
     if ((identical(value, 'abstract') && optional('class', token.next))
         || identical(value, 'class')) {
       return parseClassOrNamedMixinApplication(token);
+    } else if (identical(value, 'enum')) {
+      return parseEnum(token);
     } else if (identical(value, 'typedef')) {
       return parseTypedef(token);
     } else if (identical(value, 'library')) {
       return parseLibraryName(token);
     } else if (identical(value, 'import')) {
       return parseImport(token);
     } else if (identical(value, 'export')) {
       return parseExport(token);
     } else if (identical(value, 'part')) {
       return parsePartOrPartOf(token);
@@ skipping 372 matching lines @@
     BeginGroupToken beginGroupToken = token;
     Token endGroup = beginGroupToken.endGroup;
     if (endGroup == null) {
       return listener.unmatched(beginGroupToken);
     } else if (!identical(endGroup.kind, $CLOSE_CURLY_BRACKET)) {
       return listener.unmatched(beginGroupToken);
     }
     return beginGroupToken.endGroup;
   }
 
+  Token parseEnum(Token token) {
+    listener.beginEnum(token);
+    Token enumKeyword = token;
+    token = parseIdentifier(token.next);
+    token = expect('{', token);
+    int count = 0;
+    if (!optional('}', token)) {
+      token = parseIdentifier(token);
+      count++;
+      while (optional(',', token)) {
+        token = token.next;
+        if (optional('}', token)) break;
+        token = parseIdentifier(token);
+        count++;
+      }
+    }
+    Token endBrace = token;
+    token = expect('}', token);
+    listener.endEnum(enumKeyword, endBrace, count);
+    return token;
+  }
+
   Token parseClassOrNamedMixinApplication(Token token) {
     Token begin = token;
     Token abstractKeyword;
     if (optional('abstract', token)) {
       abstractKeyword = token;
       token = token.next;
     }
     Token classKeyword = token;
     var isMixinApplication = optional('=', peekAfterType(token.next));
     if (isMixinApplication) {
@@ skipping 1979 matching lines @@
     }
     listener.handleContinueStatement(hasTarget, continueKeyword, token);
     return expectSemicolon(token);
   }
 
   Token parseEmptyStatement(Token token) {
     listener.handleEmptyStatement(token);
     return expectSemicolon(token);
   }
 }