Fix an analyzer error in http and barback.

pkg/http/lib/src/utils.dart

 // Copyright (c) 2012, 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 utils;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
@@ skipping 94 matching lines @@
 
 /// Returns whether [string] is composed entirely of ASCII-compatible
 /// characters.
 bool isPlainAscii(String string) => _ASCII_ONLY.hasMatch(string);
 
 /// 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);
 }
 
 /// If [stream] is already a [ByteStream], returns it. Otherwise, wraps it in a
 /// [ByteStream].
 ByteStream toByteStream(Stream<List<int>> stream) {
   if (stream is ByteStream) return stream;
   return new ByteStream(stream);
 }
 
@@ skipping 100 matching lines @@
 /// The return values of all [Future]s are discarded. Any errors will cause the
 /// iteration to stop and will be piped through the return value.
 Future forEachFuture(Iterable input, Future fn(element)) {
   var iterator = input.iterator;
   Future nextElement(_) {
     if (!iterator.moveNext()) return new Future.value();
     return fn(iterator.current).then(nextElement);
   }
   return nextElement(null);
 }