Recommit changing List.skip/take/revert returns Iterable and remove mappedBy.

tests/lib/async/stream_controller_async_test.dart

 // Copyright (c) 2011, 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.
 
 // Test the basic StreamController and StreamController.singleSubscription.
 library stream_controller_async_test;
 
 import 'dart:async';
 import 'dart:isolate';
 import '../../../pkg/unittest/lib/unittest.dart';
@@ skipping 421 matching lines @@
       f.then((v) { Expect.fail("unreachable"); },
              onError: expectAsync1((e) { Expect.identical(error, e); }));
       // Need two values to trigger compare for min/max.
       c.add(0);
       c.add(1);
       c.close();
     });
   }
 
   testStream("where", (s, act) => s.where(act));
-  testStream("mappedBy", (s, act) => s.map(act));
+  testStream("map", (s, act) => s.map(act));
   testStream("expand", (s, act) => s.expand(act));
   testStream("where", (s, act) => s.where(act));
   testStreamError("handleError", (s, act) => s.handleError(act));
   testStreamError("handleTest", (s, act) => s.handleError((v) {}, test: act));
   testFuture("every", (s, act) => s.every(act));
   testFuture("any", (s, act) => s.any(act));
   testFuture("min", (s, act) => s.min((a, b) => act(b)));
   testFuture("max", (s, act) => s.max((a, b) => act(b)));
   testFuture("reduce", (s, act) => s.reduce(0, (a,b) => act(b)));
 }
 
 main() {
   testController();
   testSingleController();
   testExtraMethods();
   testPause();
   testRethrow();
 }