Remove unused library patch code.

sdk/lib/_internal/lib/io_patch.dart

Index: sdk/lib/_internal/lib/io_patch.dart
diff --git a/sdk/lib/_internal/lib/io_patch.dart b/sdk/lib/_internal/lib/io_patch.dart
index b87d04586b9c8804f4924711ad70cfad676d41a9..13e02de1ec9ff2320ebb4511ea7ec675f1a51bb9 100644
--- a/sdk/lib/_internal/lib/io_patch.dart
+++ b/sdk/lib/_internal/lib/io_patch.dart
@@ -27,9 +27,6 @@ patch class _Directory {
   patch static List _list(String path, bool recursive, bool followLinks) {
     throw new UnsupportedError("Directory._list");
   }
-  patch static SendPort _newServicePort() {
-    throw new UnsupportedError("Directory._newServicePort");
-  }
 }
 
 patch class _EventHandler {
@@ -40,12 +37,6 @@ patch class _EventHandler {
   }
 }
 
-patch class _FileUtils {
-  patch static SendPort _newServicePort() {
-    throw new UnsupportedError("FileUtils._newServicePort");
-  }
-}
-
 patch class FileStat {
   patch static List<int> _statSync(String path) {
     throw new UnsupportedError("FileStat.stat");
@@ -300,9 +291,6 @@ patch class _SecureFilter {
   patch factory _SecureFilter() {
     throw new UnsupportedError("_SecureFilter._SecureFilter");
   }
-  patch static SendPort _newServicePort() {
-    throw new UnsupportedError("_SecureFilter._newServicePort");
-  }
 }
 
 patch class _StdIOUtils {