Clean up leg.dart.

dart/lib/compiler/implementation/dart_backend/dart_backend.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.
 
-#library('dart_backend');
+library dart_backend;
 
-#import('../elements/elements.dart');
-#import('../leg.dart');
-#import('../scanner/scannerlib.dart');
-#import('../tree/tree.dart');
-#import('../universe/universe.dart');
-#import('../util/util.dart');
+import '../elements/elements.dart';
+import '../dart2jslib.dart';
+import '../tree/tree.dart';
+import '../util/util.dart';
 
-#source('backend.dart');
-#source('emitter.dart');
-#source('renamer.dart');
-#source('placeholder_collector.dart');
-#source('utils.dart');
+import '../scanner/scannerlib.dart' show StringToken,
+                                         Keyword,
+                                         IDENTIFIER_INFO;
+
+part 'backend.dart';
+part 'emitter.dart';
+part 'renamer.dart';
+part 'placeholder_collector.dart';
+part 'utils.dart';