Add library mapping.

dart/lib/compiler/implementation/frog_leg.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('frog_leg');
 
+#import('dart:io');
+
 #import('../../uri/uri.dart');
 #import('source_file.dart');
 #import('../../../frog/lang.dart', prefix: 'frog');
 #import('../compiler.dart', prefix: 'compiler');
-#import('io/io.dart', prefix: 'io');
 
 String relativize(Uri base, Uri uri) {
   if (base.scheme == 'file' &&
       base.scheme == uri.scheme &&
       base.userInfo == uri.userInfo &&
       base.domain == uri.domain &&
       base.port == uri.port &&
       uri.query == "" && uri.fragment == "") {
     if (uri.path.startsWith(base.path)) {
       return uri.path.substring(base.path.length);
@@ skipping 15 matching lines @@
     sb.add('${uriParts.last()}');
     return sb.toString();
   }
   return uri.toString();
 }
 
 bool compile(frog.World world) {
   final throwOnError = frog.options.throwOnErrors;
   final showWarnings = frog.options.showWarnings;
   final allowMockCompilation = frog.options.allowMockCompilation;
-  Uri cwd = new Uri(scheme: 'file', path: io.getCurrentDirectory());
+  Uri cwd = new Uri(scheme: 'file', path: getCurrentDirectory());
   Uri uri = cwd.resolve(frog.options.dartScript);
   String frogLibDir = frog.options.libDir;
   if (!frogLibDir.endsWith("/")) frogLibDir = "$frogLibDir/";
   Uri frogLib = new Uri(scheme: 'file', path: frogLibDir);
-  Uri libraryRoot = frogLib.resolve('../../lib/compiler/implementation/lib/');
+  Uri libraryRoot = frogLib.resolve('../../');
   Map<String, SourceFile> sourceFiles = <SourceFile>{};
 
   Future<String> provider(Uri uri) {
     if (uri.scheme != 'file') {
       throw new IllegalArgumentException(uri);
     }
     String source = world.files.readAll(uri.path);
     world.dartBytesRead += source.length;
     sourceFiles[uri.toString()] =
       new SourceFile(relativize(cwd, uri), source);
@@ skipping 28 matching lines @@
   world.legCode = code;
   world.jsBytesWritten = code.length;
   return true;
 }
 
 class AbortLeg {
   final message;
   AbortLeg(this.message);
   toString() => 'Aborted due to --throw-on-error: $message';
 }
+
+String getCurrentDirectory() {
+  String dir = new File(".").fullPathSync();
+  if (dir.endsWith("/")) return dir;
+  return "$dir/";
+}