Added type variable to generic in Stream#take() so that subsequent type checks will work correctly.

tests/lib/async/stream_typecheck_test.dart

Index: tests/lib/async/stream_typecheck_test.dart
diff --git a/tests/lib/async/stream_typecheck_test.dart b/tests/lib/async/stream_typecheck_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..1a7da091c2edc6dceff0ff272361d4c3d902919d
--- /dev/null
+++ b/tests/lib/async/stream_typecheck_test.dart
@@ -0,0 +1,30 @@
+import "package:expect/expect.dart";
+import 'dart:async';
+
+
+test_stream() {
+  Stream<int> numbers = new Stream<int>.fromIterable([1,2,3,4,5]);
+
+  Expect.equals(numbers is Stream<int>, true, "Stream should be Stream<int>");
+  Expect.equals(numbers is Stream<String>, false, "Stream<int> should not be Stream<String>");
+
+  Expect.equals(numbers is Stream<int>, true, "Stream<int> should be Stream<int>");
+  Expect.equals(numbers is Stream<String>, false, "Stream<int> should not be Stream<String>");
+}
+
+test_stream_from_controller() {
+  StreamController<int> sc = new StreamController<int>();
+  Stream numbers = new Stream.fromIterable([1,2,3,4,5]);
+  sc.addStream(numbers).then((_) => sc.close());
+
+  Expect.equals(sc.stream is Stream<int>, true, "Stream should not be Stream<String>");
+  Expect.equals(sc.stream is Stream<String>, false, "Stream<int> should not be Stream<String>");
+
+  Expect.equals(sc.stream.take(1) is Stream<int>, true, "Stream should not be Stream<String>");
+  Expect.equals(sc.stream.take(1) is Stream<String>, false, "Stream<int> should not be Stream<String>");
+}
+
+main() {
+    test_stream();
+    test_stream_from_controller();
+}