Reapply "Mark all private functions in dart: libraries as invisible (*sniff*). Previously these fun…

sdk/lib/_internal/compiler/js_lib/io_patch.dart

 // Copyright (c) 2013, 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.
 
 import 'dart:_js_helper' show patch;
 
 @patch
 class _Directory {
   @patch
   static _current() {
@@ skipping 437 matching lines @@
 class _WindowsCodePageEncoder {
   @patch
   static List<int> _encodeString(String string) {
     throw new UnsupportedError("_WindowsCodePageEncoder._encodeString");
   }
 }
 
 @patch
 class _Filter {
   @patch
-  static _Filter newZLibDeflateFilter(bool gzip, int level,
-                                      int windowBits, int memLevel,
-                                      int strategy,
-                                      List<int> dictionary, bool raw) {
-    throw new UnsupportedError("newZLibDeflateFilter");
+  static _Filter _newZLibDeflateFilter(bool gzip, int level,
+                                       int windowBits, int memLevel,
+                                       int strategy,
+                                       List<int> dictionary, bool raw) {
+    throw new UnsupportedError("_newZLibDeflateFilter");
   }
   @patch
-  static _Filter newZLibInflateFilter(int windowBits,
-                                      List<int> dictionary, bool raw) {
-    throw new UnsupportedError("newZLibInflateFilter");
+  static _Filter _newZLibInflateFilter(int windowBits,
+                                       List<int> dictionary, bool raw) {
+    throw new UnsupportedError("_newZLibInflateFilter");
   }
 }
 
 @patch
 class Stdin {
   @patch
   int readByteSync() {
     throw new UnsupportedError("Stdin.readByteSync");
   }
   @patch
@@ skipping 39 matching lines @@
   }
   @patch
   static bool get isSupported {
     throw new UnsupportedError("_FileSystemWatcher.isSupported");
   }
 }
 
 @patch
 class _IOService {
   @patch
-  static Future dispatch(int request, List data) {
-    throw new UnsupportedError("_IOService.dispatch");
+  static Future _dispatch(int request, List data) {
+    throw new UnsupportedError("_IOService._dispatch");
   }
 }