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

sdk/lib/io/file.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.
 
 part of dart.io;
 
 /**
  * FileMode describes the modes in which a file can be opened.
  */
 class FileMode {
@@ skipping 186 matching lines @@
    * * [FileMode.WRITE]: truncates the file to length zero.
    * * [FileMode.APPEND]: sets the initial write position to the end
    *   of the file.
    *
    *  When writing strings through the returned [IOSink] the encoding
    *  specified using [encoding] will be used. The returned [IOSink]
    *  has an [:encoding:] property which can be changed after the
    *  [IOSink] has been created.
    */
   IOSink openWrite({FileMode mode: FileMode.WRITE,
-                    Encoding encoding: Encoding.UTF_8});
+                    Encoding encoding: UTF8});
 
   /**
    * Read the entire file contents as a list of bytes. Returns a
    * [:Future<List<int>>:] that completes with the list of bytes that
    * is the contents of the file.
    */
   Future<List<int>> readAsBytes();
 
   /**
    * Synchronously read the entire file contents as a list of bytes.
    *
    * Throws a [FileException] if the operation fails.
    */
   List<int> readAsBytesSync();
 
   /**
    * Read the entire file contents as a string using the given
    * [Encoding].
    *
    * Returns a [:Future<String>:] that completes with the string once
    * the file contents has been read.
    */
-  Future<String> readAsString({Encoding encoding: Encoding.UTF_8});
+  Future<String> readAsString({Encoding encoding: UTF8});
 
   /**
    * Synchronously read the entire file contents as a string using the
    * given [Encoding].
    *
    * Throws a [FileException] if the operation fails.
    */
-  String readAsStringSync({Encoding encoding: Encoding.UTF_8});
+  String readAsStringSync({Encoding encoding: UTF8});
 
   /**
    * Read the entire file contents as lines of text using the given
    * [Encoding].
    *
    * Returns a [:Future<List<String>>:] that completes with the lines
    * once the file contents has been read.
    */
-  Future<List<String>> readAsLines({Encoding encoding: Encoding.UTF_8});
+  Future<List<String>> readAsLines({Encoding encoding: UTF8});
 
   /**
    * Synchronously read the entire file contents as lines of text
    * using the given [Encoding].
    *
    * Throws a [FileException] if the operation fails.
    */
-  List<String> readAsLinesSync({Encoding encoding: Encoding.UTF_8});
+  List<String> readAsLinesSync({Encoding encoding: UTF8});
 
   /**
    * Write a list of bytes to a file.
    *
    * Opens the file, writes the list of bytes to it, and closes the file.
    * Returns a [:Future<File>:] that completes with this [File] object once
    * the entire operation has completed.
    *
    * By default [writeAsBytes] creates the file for writing and truncates the
    * file if it already exists. In order to append the bytes to an existing
@@ skipping 20 matching lines @@
    * Opens the file, writes the string in the given encoding, and closes the
    * file. Returns a [:Future<File>:] that completes with this [File] object
    * once the entire operation has completed.
    *
    * By default [writeAsString] creates the file for writing and truncates the
    * file if it already exists. In order to append the bytes to an existing
    * file, pass [FileMode.APPEND] as the optional mode parameter.
    */
   Future<File> writeAsString(String contents,
                              {FileMode mode: FileMode.WRITE,
-                              Encoding encoding: Encoding.UTF_8});
+                              Encoding encoding: UTF8});
 
   /**
    * Synchronously write a string to a file.
    *
    * Opens the file, writes the string in the given encoding, and closes the
    * file.
    *
    * By default [writeAsStringSync] creates the file for writing and
    * truncates the file if it already exists. In order to append the bytes
    * to an existing file, pass [FileMode.APPEND] as the optional mode
    * parameter.
    *
    * Throws a [FileException] if the operation fails.
    */
   void writeAsStringSync(String contents,
                          {FileMode mode: FileMode.WRITE,
-                          Encoding encoding: Encoding.UTF_8});
+                          Encoding encoding: UTF8});
 
   /**
    * Get the path of the file.
    */
   String get path;
 }
 
 
 /**
  * [RandomAccessFile] provides random access to the data in a
@@ skipping 97 matching lines @@
    * Throws a [FileException] if the operation fails.
    */
   void writeFromSync(List<int> buffer, [int start, int end]);
 
   /**
    * Writes a string to the file using the given [Encoding]. Returns a
    * [:Future<RandomAccessFile>:] that completes with this
    * RandomAccessFile when the write completes.
    */
   Future<RandomAccessFile> writeString(String string,
-                                       {Encoding encoding: Encoding.UTF_8});
+                                       {Encoding encoding: UTF8});
 
   /**
    * Synchronously writes a single string to the file using the given
    * [Encoding].
    *
    * Throws a [FileException] if the operation fails.
    */
   void writeStringSync(String string,
-                       {Encoding encoding: Encoding.UTF_8});
+                       {Encoding encoding: UTF8});
 
   /**
    * Gets the current byte position in the file. Returns a
    * [:Future<int>:] that completes with the position.
    */
   Future<int> position();
 
   /**
    * Synchronously gets the current byte position in the file.
    *
@@ skipping 89 matching lines @@
       }
     } else if (osError != null) {
       sb.write(": osError");
       if (path != null) {
         sb.write(", path = $path");
       }
     }
     return sb.toString();
   }
 }