Allow Object when doing lookups.

sdk/lib/async/stream.dart

Index: sdk/lib/async/stream.dart
diff --git a/sdk/lib/async/stream.dart b/sdk/lib/async/stream.dart
index bff0435af274aef86df2fb9a4f2bcb14d61df57c..f52fd84519be7e2660e7bf990f6087a4d10234be 100644
--- a/sdk/lib/async/stream.dart
+++ b/sdk/lib/async/stream.dart
@@ -307,12 +307,12 @@ abstract class Stream<T> {
   }
 
   /**
-   * Checks whether [match] occurs in the elements provided by this stream.
+   * Checks whether [needle] occurs in the elements provided by this stream.
    *
    * Completes the [Future] when the answer is known.
    * If this stream reports an error, the [Future] will report that error.
    */
-  Future<bool> contains(T match) {
+  Future<bool> contains(Object needle) {
     _FutureImpl<bool> future = new _FutureImpl<bool>();
     StreamSubscription subscription;
     subscription = this.listen(
@@ -320,7 +320,7 @@ abstract class Stream<T> {
         // checked mode. http://dartbug.com/7733
         (/*T*/ element) {
           _runUserCode(
-            () => (element == match),
+            () => (element == needle),
             (bool isMatch) {
               if (isMatch) {
                 subscription.cancel();