[dart:io] Move _getUriBaseClosure to dart:io

runtime/bin/builtin.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 builtin;
 
 // NOTE: Do not import 'dart:io' in builtin.
 import 'dart:async';
 import 'dart:collection' hide LinkedList, LinkedListEntry;
 import 'dart:_internal' hide Symbol;
@@ skipping 12 matching lines @@
 // The standalone embedder registers the closurized _print function with the
 // dart:core library.
 void _printString(String s) native "Builtin_PrintString";
 
 void _print(arg) {
   _printString(arg.toString());
 }
 
 _getPrintClosure() => _print;
 
-// Corelib 'Uri.base' implementation.
-// Uri.base is susceptible to changes in the current working directory.
-_getCurrentDirectoryPath() native "Builtin_GetCurrentDirectory";
-
-Uri _uriBase() {
-  // We are not using Dircetory.current here to limit the dependency
-  // on dart:io. This code is the same as:
-  //   return new Uri.directory(Directory.current.path);
-  var path = _getCurrentDirectoryPath();
-  return new Uri.directory(path);
-}
-
-_getUriBaseClosure() => _uriBase;
-
 // Asynchronous loading of resources.
 // The embedder forwards loading requests to the service isolate.
 
 // A port for communicating with the service isolate for I/O.
 SendPort _loadPort;
 
 // The isolateId used to communicate with the service isolate for I/O.
 int _isolateId;
 
 // Requests made to the service isolate over the load port.
@@ skipping 316 matching lines @@
     if (_traceLoading) {
       _log("Exception when resolving package URI: $packageUri");
     }
     result = null;
   }
   if (_traceLoading) {
     _log("Resolved '$packageUri' to '$result'");
   }
   return result;
 }