Revert "Add test for cancel-future being awaited after an `await for`."

tests/language/await_for_test.dart

 // Copyright (c) 2014, 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.
 
 import "dart:async";
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 
 class Trace {
-  String trace;
-  Trace(this.trace);
-  void record(x) {
+  String trace = "";
+  record(x) {
     trace += x.toString();
   }
-  String toString() => trace;
+  toString() => trace;
 }
 
 
 Stream makeMeAStream() {
   return timedCounter(5);
 }
 
+Trace t1 = new Trace();
 
-consumeOne(trace) async {
+consumeOne() async {
   // Equivalent to await for (x in makeMeAStream()) { ... }
   var s = makeMeAStream();
   var it = new StreamIterator(s);
   while (await it.moveNext()) {
     var x = it.current;
-    trace.record(x);
+    t1.record(x);
   }
-  trace.record("X");
+  t1.record("X");
 }
 
+Trace t2 = new Trace();
 
-consumeTwo(trace) async {
+consumeTwo() async {
   await for (var x in makeMeAStream()) {
-    trace.record(x);
+    t2.record(x);
   }
-  trace.record("Y");
+  t2.record("Y");
 }
 
+Trace t3 = new Trace();
 
-consumeNested(trace) async {
+consumeNested() async {
   await for (var x in makeMeAStream()) {
-    trace.record(x);
+    t3.record(x);
     await for (var y in makeMeAStream()) {
-      trace.record(y);
+      t3.record(y);
     }
-    trace.record("|");
+    t3.record("|");
   }
-  trace.record("Z");
+  t3.record("Z");
 }
 
-consumeSomeOfInfinite(trace) async {
+Trace t4 = new Trace();
+
+consumeSomeOfInfinite() async {
   int i = 0;
   await for (var x in infiniteStream()) {
     i++;
     if (i > 10) break;
-    trace.record(x);
+    t4.record(x);
   }
-  trace.record("U");
-}
-
-const String cancelError =
-    "ERROR: Error in future returned by .cancel() must be caught";
-
-/// Creates a stream that yields integers forever, but throws when canceled.
-///
-/// The thrown error should end up in the future returned by `cancel`.
-Stream<int> errorOnCancelStream(int n) async* {
-  try {
-    while (true) yield n++;
-  } finally {
-    throw cancelError;
-  }
-}
-
-
-// Sanity-check that the errorOnCancelStream behaves as expected.
-testErrorOnCancel() {
-  var stream = errorOnCancelStream(0);
-  var subscription = stream.listen(null);
-  return subscription.cancel().then((_) {
-    Expect.fail("Cancel future did not contain error");
-  }, onError: (e) {
-    Expect.equals(cancelError, e);
-  });
-}
-
-testCancelAwaited() async {
-  return runZoned(() async {
-    var stream = errorOnCancelStream(0);
-    try {
-      var n = 0;
-      await for (var x in stream) {
-        Expect.equals(n++, x);
-        if (x == 5) break;
-      }
-      Expect.fail("Didn't await the cancel future.");
-    } on String catch (e) {
-      Expect.equals(cancelError, e);
-    }
-  }, onError: (e) {
-    // Catch the error if it's uncaught.
-    if (cancelError == e) {
-      Expect.fail("Error in cancel is considered uncaught");
-    }
-    throw e;
-  });
+  t4.record("U");
 }
 
 main() {
-  Trace t1 = new Trace("T1:");
-  var f1 = consumeOne(t1);
+  var f1 = consumeOne();
+  t1.record("T1:");
 
-  Trace t2 = new Trace("T2:");
-  var f2 = consumeTwo(t2);
-
-  Trace t3 = new Trace("T3:");
-  var f3 = consumeNested(t3);
-
-  Trace t4 = new Trace("T4:");
-  var f4 = consumeSomeOfInfinite(t4);
-
-  var f5 = testErrorOnCancel();
-
-  var f6 = testCancelAwaited();
+  var f2 = consumeTwo();
+  t2.record("T2:");
+ 
+  var f3 = consumeNested();
+  t3.record("T3:");
+ 
+  var f4 = consumeSomeOfInfinite();
+  t4.record("T4:");
 
   asyncStart();
-  Future.wait([f1, f2, f3, f4, f5, f6]).then((_) {
+  Future.wait([f1, f2, f3, f4]).then((_) {
     Expect.equals("T1:12345X", t1.toString());
     Expect.equals("T2:12345Y", t2.toString());
     Expect.equals("T3:112345|212345|312345|412345|512345|Z", t3.toString());
     Expect.equals("T4:12345678910U", t4.toString());
     asyncEnd();
   });
 }
 
 // Create a stream that produces numbers [1, 2, ... maxCount]
 Stream timedCounter(int maxCount) {
@@ skipping 53 matching lines @@
   }
 
   controller = new StreamController(
       onListen: startTimer,
       onPause: stopTimer,
       onResume: startTimer,
       onCancel: stopTimer);
 
   return controller.stream;
 }