Use metadata annotation @patch for patch classes

runtime/bin/file_patch.dart

Index: runtime/bin/file_patch.dart
diff --git a/runtime/bin/file_patch.dart b/runtime/bin/file_patch.dart
index a3d42e81f285c751c1a25078d986a1cd30db584f..8795b9c8848e2363356f595ca2b107fd0f04dd2e 100644
--- a/runtime/bin/file_patch.dart
+++ b/runtime/bin/file_patch.dart
@@ -2,28 +2,28 @@
 // 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.
 
-patch class _File {
-  /* patch */ static _exists(String path) native "File_Exists";
-  /* patch */ static _create(String path) native "File_Create";
-  /* patch */ static _createLink(String path, String target)
+@patch class _File {
+  /* @patch */ static _exists(String path) native "File_Exists";
+  /* @patch */ static _create(String path) native "File_Create";
+  /* @patch */ static _createLink(String path, String target)
       native "File_CreateLink";
-  /* patch */ static _linkTarget(String path) native "File_LinkTarget";
-  /* patch */ static _deleteNative(String path) native "File_Delete";
-  /* patch */ static _deleteLinkNative(String path) native "File_DeleteLink";
-  /* patch */ static _rename(String oldPath, String newPath)
+  /* @patch */ static _linkTarget(String path) native "File_LinkTarget";
+  /* @patch */ static _deleteNative(String path) native "File_Delete";
+  /* @patch */ static _deleteLinkNative(String path) native "File_DeleteLink";
+  /* @patch */ static _rename(String oldPath, String newPath)
       native "File_Rename";
-  /* patch */ static _renameLink(String oldPath, String newPath)
+  /* @patch */ static _renameLink(String oldPath, String newPath)
       native "File_RenameLink";
-  /* patch */ static _copy(String oldPath, String newPath) native "File_Copy";
-  /* patch */ static _lengthFromPath(String path) native "File_LengthFromPath";
-  /* patch */ static _lastModified(String path) native "File_LastModified";
-  /* patch */ static _open(String path, int mode) native "File_Open";
-  /* patch */ static int _openStdio(int fd) native "File_OpenStdio";
+  /* @patch */ static _copy(String oldPath, String newPath) native "File_Copy";
+  /* @patch */ static _lengthFromPath(String path) native "File_LengthFromPath";
+  /* @patch */ static _lastModified(String path) native "File_LastModified";
+  /* @patch */ static _open(String path, int mode) native "File_Open";
+  /* @patch */ static int _openStdio(int fd) native "File_OpenStdio";
 }
 
 
-patch class _RandomAccessFileOps {
-  /* patch */ factory _RandomAccessFileOps(int pointer)
+@patch class _RandomAccessFileOps {
+  /* @patch */ factory _RandomAccessFileOps(int pointer)
       => new _RandomAccessFileOpsImpl(pointer);
 }
 
@@ -62,7 +62,7 @@ class _WatcherPath {
 }
 
 
-patch class _FileSystemWatcher {
+@patch class _FileSystemWatcher {
   static int _id;
   static final Map<int, _WatcherPath> _idMap = {};
 
@@ -74,7 +74,7 @@ patch class _FileSystemWatcher {
 
   StreamController _broadcastController;
 
-  /* patch */ static Stream<FileSystemEvent> _watch(
+  /* @patch */ static Stream<FileSystemEvent> _watch(
       String path, int events, bool recursive) {
     if (Platform.isLinux) {
       return new _InotifyFileSystemWatcher(path, events, recursive).stream;
@@ -262,7 +262,7 @@ patch class _FileSystemWatcher {
     });
   }
 
-  /* patch */ static bool get isSupported
+  /* @patch */ static bool get isSupported
       native "FileSystemWatcher_IsSupported";
 
   static int _initWatcher() native "FileSystemWatcher_InitWatcher";