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

pkg/scheduled_test/lib/scheduled_process.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 scheduled_test.scheduled_process;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 64 matching lines @@
   /// [Process.start]. [description] is a string description of this process; it
   /// defaults to the command-line invocation. [encoding] is the [Encoding] that
   /// will be used for the process's input and output.
   ///
   /// [executable], [arguments], [workingDirectory], and [environment] may be
   /// either a [Future] or a concrete value. If any are [Future]s, the process
   /// won't start until the [Future]s have completed. In addition, [arguments]
   /// may be a [List] containing a mix of strings and [Future]s.
   ScheduledProcess.start(executable, arguments,
       {workingDirectory, environment, String description,
-       Encoding encoding: Encoding.UTF_8})
+       Encoding encoding: UTF8})
       : _encoding = encoding,
         _explicitDescription = description != null,
         _description = description {
     assert(currentSchedule.state == ScheduleState.SET_UP);
 
     _updateDescription(executable, arguments);
 
     _scheduleStartProcess(executable, arguments, workingDirectory, environment);
 
     _scheduleExceptionCleanup();
@@ skipping 49 matching lines @@
       ]).then((results) {
         executable = results[0];
         arguments = results[1];
         workingDirectory = results[2];
         environment = results[3];
         _updateDescription(executable, arguments);
         return Process.start(executable,
                              arguments,
                              workingDirectory: workingDirectory,
                              environment: environment).then((process) {
-          process.stdin.encoding = Encoding.UTF_8;
+          process.stdin.encoding = UTF8;
           return process;
         });
       });
     }, "starting process '$description'"));
   }
 
   /// Listens for [_process] to exit and passes the exit code to
   /// [exitCodeCompleter]. If the process completes earlier than expected, an
   /// exception will be signaled to the schedule.
   void _handleExit(Completer exitCodeCompleter) {
@@ skipping 30 matching lines @@
   Pair<Stream<String>, StreamCanceller> _lineStreamWithCanceller(
       Future<Stream<List<int>>> streamFuture) {
     return streamWithCanceller(futureStream(streamFuture)
         .handleError((e) => currentSchedule.signalError(e))
         .map((chunk) {
       // Whenever the process produces any sort of output, reset the schedule's
       // timer.
       currentSchedule.heartbeat();
       return chunk;
     })
-        .transform(new StringDecoder(_encoding))
+        .transform(_encoding.decoder)
         .transform(new LineSplitter()));
   }
 
   /// Schedule an exception handler that will clean up the process and provide
   /// debug information if an error occurs.
   void _scheduleExceptionCleanup() {
     currentSchedule.onException.schedule(() {
       _stdoutCanceller();
       _stderrCanceller();
 
@@ skipping 127 matching lines @@
     schedule(() {
       _endExpected = true;
       return _exitCode.then((exitCode) {
         if (expectedExitCode != null) {
           expect(exitCode, equals(expectedExitCode));
         }
       });
     }, "waiting for process '$description' to exit");
   }
 }