Add library mapping.

dart/frog/leg/dart2js.dart

Index: dart/frog/leg/dart2js.dart
diff --git a/dart/frog/leg/dart2js.dart b/dart/frog/leg/dart2js.dart
index 2481feae790334dad8562d119cf708bd9af78c93..b77e81753cfc927b0ef68d3d378124e55c43c33c 100644
--- a/dart/frog/leg/dart2js.dart
+++ b/dart/frog/leg/dart2js.dart
@@ -9,7 +9,6 @@
 
 #import('../../lib/uri/uri.dart');
 #import('../../frog/leg/api.dart', prefix: 'api');
-#import('../../frog/leg/io/io.dart', prefix: 'io');
 #import('../../frog/leg/colors.dart');
 #import('source_file.dart');
 
@@ -44,7 +43,7 @@ String relativize(Uri base, Uri uri) {
 }
 
 void compile(List<String> argv) {
-  Uri cwd = new Uri(scheme: 'file', path: io.getCurrentDirectory());
+  Uri cwd = new Uri(scheme: 'file', path: getCurrentDirectory());
   bool throwOnError = false;
   bool showWarnings = true;
   bool verbose = false;
@@ -151,3 +150,9 @@ String readAll(String filename) {
   file.closeSync();
   return new String.fromCharCodes(new Utf8Decoder(buffer).decodeRest());
 }
+
+String getCurrentDirectory() {
+  String dir = new File(".").fullPathSync();
+  if (dir.endsWith("/")) return dir;
+  return "$dir/";
+}