All strong mode cleaning of dart2js.

pkg/compiler/lib/src/util/setlet.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.
 
 library dart2js.util.setlet;
 
 import 'dart:collection' show IterableBase;
 
 class Setlet<E> extends IterableBase<E> implements Set<E> {
   static const _SetletMarker _MARKER = const _SetletMarker();
@@ skipping 39 matching lines @@
   bool get isEmpty {
     if (_extra == null) {
       return _MARKER == _contents;
     } else if (_MARKER == _extra) {
       return _contents.isEmpty;
     } else {
       return _extra == 0;
     }
   }
 
-  bool contains(E element) {
+  bool contains(Object element) {
     if (_extra == null) {
       return _contents == element;
     } else if (_MARKER == _extra) {
       return _contents.contains(element);
     } else {
       for (int remaining = _extra, i = 0; remaining > 0 && i < CAPACITY; i++) {
         var candidate = _contents[i];
         if (_MARKER == candidate) continue;
         if (candidate == element) return true;
         remaining--;
@@ skipping 154 matching lines @@
     } else {
       for (int remaining = _extra, i = 0; remaining > 0 && i < CAPACITY; i++) {
         var element = _contents[i];
         if (_MARKER == element) continue;
         action(element);
         remaining--;
       }
     }
   }
 
-  bool containsAll(Iterable<E> other) {
+  bool containsAll(Iterable<Object> other) {
     for (E e in other) {
       if (!this.contains(e)) return false;
     }
     ;
     return true;
   }
 
   clear() {
     _contents = _MARKER;
     _extra = null;
   }
 
   Set<E> union(Set<E> other) => new Set<E>.from(this)..addAll(other);
 
-  Setlet<E> intersection(Set<E> other) =>
+  Setlet<E> intersection(Set<Object> other) =>
       new Setlet<E>.from(this.where((e) => other.contains(e)));
 
   Setlet<E> difference(Set<Object> other) =>
       new Setlet<E>.from(this.where((e) => !other.contains(e)));
 
   Setlet<E> toSet() {
     Setlet<E> result = new Setlet<E>();
     if (_extra == null) {
       result._contents = _contents;
     } else if (_extra == _MARKER) {
@@ skipping 45 matching lines @@
       if (Setlet._MARKER != candidate) {
         _current = candidate;
         _remaining--;
         return true;
       }
     }
     _current = null;
     return false;
   }
 }