Remove String.slice. Too much overlap with String.substring.

tools/dom/docs/lib/docs.dart

 // Copyright (c) 2013, 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.
 
 /**
  * A library for extracting the documentation from the various HTML libraries
  * ([dart:html], [dart:svg], [dart:web_audio], [dart:indexed_db]) and saving
  * those documentation comments to a JSON file.
  */
 
@@ skipping 88 matching lines @@
           classMirror.members.values.toList());
 
       var membersJson = {};
       for (var memberMirror in sortedMembers) {
         var memberDomName = domNames(memberMirror)[0];
         var memberComment = _splitCommentsByNewline(
             computeUntrimmedCommentAsList(memberMirror));
 
         // Remove interface name from Dom Name.
         if (memberDomName.indexOf('.') >= 0) {
-          memberDomName = memberDomName.slice(memberDomName.indexOf('.') + 1);
+          memberDomName =
+              memberDomName.substring(memberDomName.indexOf('.') + 1);
         }
 
         if (!memberComment.isEmpty) {
           membersJson.putIfAbsent(memberDomName, () => memberComment);
         }
       }
 
       // Only include the comment if DocsEditable is set.
       var classComment = _splitCommentsByNewline(
           computeUntrimmedCommentAsList(classMirror));
@@ skipping 63 matching lines @@
     for (var s in tags.reflectee.split(',')) {
       domNames.add(s.trim());
     }
 
     if (domNames.length == 1 && domNames[0] == 'none') return <String>[];
     return domNames;
   } else {
     return <String>[];
   }
 }