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

pkg/http/lib/src/request.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 request;
 
+import 'dart:convert';
 import 'dart:io';
 import 'dart:typed_data';
 
 import 'base_request.dart';
 import 'byte_stream.dart';
 import 'utils.dart';
 
 /// An HTTP request where the entire request body is known in advance.
 class Request extends BaseRequest {
   /// The size of the request body, in bytes. This is calculated from
@@ skipping 12 matching lines @@
   /// [body]. This is only used if [encoding] hasn't been manually set and if
   /// the content-type header has no encoding information.
   Encoding _defaultEncoding;
 
   /// The encoding used for the request. This encoding is used when converting
   /// between [bodyBytes] and [body].
   ///
   /// If the request has a `Content-Type` header and that header has a `charset`
   /// parameter, that parameter's value is used as the encoding. Otherwise, if
   /// [encoding] has been set manually, that encoding is used. If that hasn't
-  /// been set either, this defaults to [Encoding.UTF_8].
+  /// been set either, this defaults to [UTF8].
   ///
   /// If the `charset` parameter's value is not a known [Encoding], reading this
   /// will throw a [FormatException].
   ///
   /// If the request has a `Content-Type` header, setting this will set the
   /// charset parameter on that header.
   Encoding get encoding {
     if (_contentType == null || _contentType.charset == null) {
       return _defaultEncoding;
     }
@@ skipping 26 matching lines @@
     _bodyBytes = toUint8List(value);
   }
 
   /// The body of the request as a string. This is converted to and from
   /// [bodyBytes] using [encoding].
   ///
   /// When this is set, if the request does not yet have a `Content-Type`
   /// header, one will be added with the type `text/plain`. Then the `charset`
   /// parameter of the `Content-Type` header (whether new or pre-existing) will
   /// be set to [encoding] if it wasn't already set.
-  String get body => decodeString(bodyBytes, encoding);
+  String get body => encoding.decode(bodyBytes);
 
   set body(String value) {
-    bodyBytes = encodeString(value, encoding);
+    bodyBytes = encoding.encode(value);
     var contentType = _contentType;
     if (contentType == null) {
       contentType = new ContentType("text", "plain", charset: encoding.name);
     } else if (contentType.charset == null) {
       contentType = new ContentType(contentType.primaryType,
                                     contentType.subType,
                                     charset: encoding.name,
                                     parameters: contentType.parameters);
     }
     _contentType = contentType;
@@ skipping 30 matching lines @@
       throw new StateError('Cannot set the body fields of a Request with '
           'content-type "${_contentType.value}".');
     }
 
     this.body = mapToQuery(fields);
   }
 
   /// Creates a new HTTP request.
   Request(String method, Uri url)
     : super(method, url),
-      _defaultEncoding = Encoding.UTF_8,
+      _defaultEncoding = UTF8,
       _bodyBytes = new Uint8List(0);
 
   /// Freezes all mutable fields and returns a single-subscription [ByteStream]
   /// containing the request body.
   ByteStream finalize() {
     super.finalize();
     return new ByteStream.fromBytes(bodyBytes);
   }
 
   /// The `Content-Type` header of the request (if it exists) as a
   /// [ContentType].
   ContentType get _contentType {
     var contentType = headers[HttpHeaders.CONTENT_TYPE];
     if (contentType == null) return null;
     return ContentType.parse(contentType);
   }
 
   set _contentType(ContentType value) {
     headers[HttpHeaders.CONTENT_TYPE] = value.toString();
   }
 
   /// Throw an error if this request has been finalized.
   void _checkFinalized() {
     if (!finalized) return;
     throw new StateError("Can't modify a finalized Request.");
   }
 }