Fix an analyzer error in http and barback.

pkg/barback/lib/src/utils.dart

 // Copyright (c) 2013, 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 barback.utils;
 
 import 'dart:async';
 import 'dart:typed_data';
 
 /// A pair of values.
@@ skipping 67 matching lines @@
 
   const DIGITS = "0123456789abcdef";
   return DIGITS[(byte ~/ 16) % 16] + DIGITS[byte % 16];
 }
 
 /// Converts [input] into a [Uint8List].
 ///
 /// If [input] is a [TypedData], this just returns a view on [input].
 Uint8List toUint8List(List<int> input) {
   if (input is Uint8List) return input;
-  if (input is TypedData) return new Uint8List.view(input.buffer);
+  if (input is TypedData) {
+    // TODO(nweiz): remove "as" when issue 11080 is fixed.
+    return new Uint8List.view((input as TypedData).buffer);
+  }
   return new Uint8List.fromList(input);
 }
 
 /// Group the elements in [iter] by the value returned by [fn].
 ///
 /// This returns a map whose keys are the return values of [fn] and whose values
 /// are lists of each element in [iter] for which [fn] returned that key.
 Map<Object, List> groupBy(Iterable iter, fn(element)) {
   var map = {};
   for (var element in iter) {
@@ skipping 149 matching lines @@
     subscription = callback().listen(controller.add,
         onError: controller.addError,
         onDone: controller.close);
   },
       onCancel: () => subscription.cancel(),
       onPause: () => subscription.pause(),
       onResume: () => subscription.resume(),
       sync: true);
   return controller.stream;
 }