dart:developer service extension fixes

sdk/lib/io/file_impl.dart

Index: sdk/lib/io/file_impl.dart
diff --git a/sdk/lib/io/file_impl.dart b/sdk/lib/io/file_impl.dart
index 5dd559c1835ee022d6afac71a9409a7a1ed414d3..0d0bc9e3a1868bd04c0be55354828e62b2b978c0 100644
--- a/sdk/lib/io/file_impl.dart
+++ b/sdk/lib/io/file_impl.dart
@@ -595,9 +595,9 @@ class _RandomAccessFile
       // We need to make sure that these are always awailable from the
       // observatory even if no files (or sockets for the socket ones) are
       // open.
-      registerExtension('__getOpenFiles',
+      registerExtension('ext.dart.io.getOpenFiles',
                         _FileResourceInfo.getOpenFiles);
-      registerExtension('__getFileByID',
+      registerExtension('ext.dart.io.getFileByID',
                         _FileResourceInfo.getFileInfoMapByID);
       _connectedResourceHandler = true;
     }