Fix unresolved classes issues in dart:io.

sdk/lib/io/stdio.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.
 
 const int _STDIO_HANDLE_TYPE_TERMINAL = 0;
 const int _STDIO_HANDLE_TYPE_PIPE = 1;
 const int _STDIO_HANDLE_TYPE_FILE = 2;
 const int _STDIO_HANDLE_TYPE_SOCKET = 3;
 const int _STDIO_HANDLE_TYPE_OTHER = -1;
 
 
 InputStream _stdin;
 OutputStream _stdout;
 OutputStream _stderr;
 
 
-InputStream _getStdioInputStream() {
-  switch (_StdIOUtils._getStdioHandleType(0)) {
-    case _STDIO_HANDLE_TYPE_TERMINAL:
-    case _STDIO_HANDLE_TYPE_PIPE:
-    case _STDIO_HANDLE_TYPE_SOCKET:
-      Socket s = new _Socket._internalReadOnly();
-      _StdIOUtils._getStdioHandle(s, 0);
-      s._closed = false;
-      return s.inputStream;
-    case _STDIO_HANDLE_TYPE_FILE:
-      return new _FileInputStream.fromStdio(0);
-    default:
-      throw new FileIOException("Unsupported stdin type");
-  }
-}
-
-
-OutputStream _getStdioOutputStream(int fd) {
-  assert(fd == 1 || fd == 2);
-  switch (_StdIOUtils._getStdioHandleType(fd)) {
-    case _STDIO_HANDLE_TYPE_TERMINAL:
-    case _STDIO_HANDLE_TYPE_PIPE:
-    case _STDIO_HANDLE_TYPE_SOCKET:
-      Socket s = new _Socket._internalWriteOnly();
-      _StdIOUtils._getStdioHandle(s, fd);
-      s._closed = false;
-      return s.outputStream;
-    case _STDIO_HANDLE_TYPE_FILE:
-      return new _FileOutputStream.fromStdio(fd);
-    default:
-      throw new FileIOException("Unsupported stdin type");
-  }
-}
-
-
 InputStream get stdin {
   if (_stdin == null) {
-    _stdin = _getStdioInputStream();
+    _stdin = _StdIOUtils._getStdioInputStream();
   }
   return _stdin;
 }
 
 
 OutputStream get stdout {
   if (_stdout == null) {
-    _stdout = _getStdioOutputStream(1);
+    _stdout = _StdIOUtils._getStdioOutputStream(1);
   }
   return _stdout;
 }
 
 
 OutputStream get stderr {
   if (_stderr == null) {
-    _stderr = _getStdioOutputStream(2);
+    _stderr = _StdIOUtils._getStdioOutputStream(2);
   }
   return _stderr;
 }
 
 
 class _StdIOUtils {
-  external static _getStdioHandle(Socket socket, int num);
-  external static _getStdioHandleType(int num);
+  external static OutputStream _getStdioOutputStream(int fd);
+  external static InputStream _getStdioInputStream();
 }