Cleanup inconsistent dart:html method signatures

sdk/lib/html/html_common/css_class_set.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_common;
 
 abstract class CssClassSetImpl implements CssClassSet {
 
   String toString() {
     return readClasses().join(' ');
@@ skipping 112 matching lines @@
     // TODO - see comment above about validation.
     modify((s) => s.addAll(iterable));
   }
 
   /**
    * Remove all classes specified in [iterable] from element.
    *
    * This is the Dart equivalent of jQuery's
    * [removeClass](http://api.jquery.com/removeClass/).
    */
-  void removeAll(Iterable<String> iterable) {
+  void removeAll(Iterable<Object> iterable) {
     modify((s) => s.removeAll(iterable));
   }
 
   /**
    * Toggles all classes specified in [iterable] on element.
    *
    * Iterate through [iterable]'s items, and add it if it is not on it, or
    * remove it if it is. This is the Dart equivalent of jQuery's
    * [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.
    */
   void toggleAll(Iterable<String> iterable, [bool shouldAdd]) {
     iterable.forEach((e) => toggle(e, shouldAdd));
   }
 
-  void retainAll(Iterable<String> iterable) {
+  void retainAll(Iterable<Object> iterable) {
     modify((s) => s.retainAll(iterable));
   }
 
   void removeWhere(bool test(String name)) {
     modify((s) => s.removeWhere(test));
   }
 
   void retainWhere(bool test(String name)) {
     modify((s) => s.retainWhere(test));
   }
 
-  bool containsAll(Iterable<String> collection) =>
+  bool containsAll(Iterable<Object> collection) =>
     readClasses().containsAll(collection);
 
-  Set<String> intersection(Set<String> other) =>
+  Set<String> intersection(Set<Object> other) =>
     readClasses().intersection(other);
 
   Set<String> union(Set<String> other) =>
     readClasses().union(other);
 
   Set<String> difference(Set<String> other) =>
     readClasses().difference(other);
 
   String get first => readClasses().first;
   String get last => readClasses().last;
@@ skipping 43 matching lines @@
    */
   Set<String> readClasses();
 
   /**
    * Join all the elements of a set into one string and write
    * back to the element.
    * This is intended to be overridden by specific implementations.
    */
   void writeClasses(Set<String> s);
 }