Add "contains" method to Collection.

lib/compiler/implementation/lib/interceptors.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:_interceptors');
 
 #import('dart:coreimpl');
 
 add$1(var receiver, var value) {
   if (isJsArray(receiver)) {
@@ skipping 490 matching lines @@
 }
 
 concat(receiver, other) {
   if (receiver is !String) return UNINTERCEPTED(receiver.concat(other));
 
   if (other is !String) throw new ArgumentError(other);
   return JS('String', r'# + #', receiver, other);
 }
 
 contains$1(receiver, other) {
-  if (receiver is !String) {
-    return UNINTERCEPTED(receiver.contains(other));
+  if (receiver is String) {
+    return contains$2(receiver, other, 0);
+  } else if (isJsArray(receiver)) {
+    for (int i = 0; i < receiver.length; i++) {
+      if (other == receiver[i]) return true;
+    }
+    return false;
   }
-  return contains$2(receiver, other, 0);
+  return UNINTERCEPTED(receiver.contains(other));
 }
 
 contains$2(receiver, other, startIndex) {
   if (receiver is !String) {
     return UNINTERCEPTED(receiver.contains(other, startIndex));
   }
   checkNull(other);
   return stringContainsUnchecked(receiver, other, startIndex);
 }
 
@@ skipping 144 matching lines @@
   } else {
     return UNINTERCEPTED(receiver.runtimeType);
   }
 }
 
 // TODO(lrn): These getters should be generated automatically for all
 // intercepted methods.
 get$toString(receiver) => () => toString(receiver);
 
 get$hashCode(receiver) => () => hashCode(receiver);