Remove Encoding-enum from dart:io and add interface in dart:convert.

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';
-import 'dart:utf';
 
 import 'byte_stream.dart';
 
 /// Converts a URL query string (or `application/x-www-form-urlencoded` body)
 /// into a [Map] from parameter names to values.
 ///
 ///     queryToMap("foo=bar&baz=bang&qux");
 ///     //=> {"foo": "bar", "baz": "bang", "qux": ""}
 Map<String, String> queryToMap(String queryList) {
   var map = {};
@@ skipping 38 matching lines @@
   return [
     toSplit.substring(0, index),
     toSplit.substring(index + pattern.length)
   ];
 }
 
 /// Returns the [Encoding] that corresponds to [charset]. Returns [fallback] if
 /// [charset] is null or if no [Encoding] was found that corresponds to
 /// [charset].
 Encoding encodingForCharset(
-    String charset, [Encoding fallback = Encoding.ISO_8859_1]) {
+    String charset, [Encoding fallback = LATIN1]) {
   if (charset == null) return fallback;
-  var encoding = Encoding.fromName(charset);
+  var encoding = Encoding.getByName(charset);
   return encoding == null ? fallback : encoding;
 }
 
 
 /// Returns the [Encoding] that corresponds to [charset]. Throws a
 /// [FormatException] if no [Encoding] was found that corresponds to [charset].
 /// [charset] may not be null.
 Encoding requiredEncodingForCharset(String charset) {
-  var encoding = Encoding.fromName(charset);
+  var encoding = Encoding.getByName(charset);
   if (encoding != null) return encoding;
   throw new FormatException('Unsupported encoding "$charset".');
 }
 
-/// Converts [bytes] into a [String] according to [encoding].
-String decodeString(List<int> bytes, Encoding encoding) {
-  // TODO(nweiz): implement this once issue 6284 is fixed.
-  return decodeUtf8(bytes);
-}
-
-/// Converts [string] into a byte array according to [encoding].
-List<int> encodeString(String string, Encoding encoding) {
-  // TODO(nweiz): implement this once issue 6284 is fixed.
-  return encodeUtf8(string);
-}
-
 /// A regular expression that matches strings that are composed entirely of
 /// ASCII-compatible characters.
 final RegExp _ASCII_ONLY = new RegExp(r"^[\x00-\x7F]+$");
 
 /// 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].
@@ skipping 118 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);
 }