Format all files under tools and utils directory.

tools/dom/src/CssClassSet.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 html;
 
 /** A Set that stores the CSS class names for an element. */
 abstract class CssClassSet implements Set<String> {
-
   /**
    * Adds the class [value] to the element if it is not on it, removes it if it
    * is.
    *
    * If [shouldAdd] is true, then we always add that [value] to the element. If
    * [shouldAdd] is false then we always remove [value] from the element.
    *
    * If this corresponds to one element, returns `true` if [value] is present
    * after the operation, and returns `false` if [value] is absent after the
    * operation.
@@ skipping 83 matching lines @@
    * [toggleClass](http://api.jquery.com/toggleClass/).
    * If [shouldAdd] is true, then we always add all the classes in [iterable]
    * element. If [shouldAdd] is false then we always remove all the classes in
    * [iterable] from the element.
    *
    * Each element of [iterable] must be a valid 'token' representing a single
    * class, i.e. a non-empty string containing no whitespace.
    */
   void toggleAll(Iterable<String> iterable, [bool shouldAdd]);
 }