Add support for compression filters in the mojo dart:io

mojo/dart/embedder/io/filter_patch.dart

Index: mojo/dart/embedder/io/filter_patch.dart
diff --git a/mojo/dart/embedder/io/filter_patch.dart b/mojo/dart/embedder/io/filter_patch.dart
new file mode 100644
index 0000000000000000000000000000000000000000..3a321703b62045bb99d2ef8ee17f2c098c001089
--- /dev/null
+++ b/mojo/dart/embedder/io/filter_patch.dart
@@ -0,0 +1,45 @@
+// 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.
+
+
+class _FilterImpl extends NativeFieldWrapperClass1 implements _Filter {
+  void process(List<int> data, int start, int end) native "Filter_Process";
+
+  List<int> processed({bool flush: true, bool end: false})
+      native "Filter_Processed";
+
+  void end() native "Filter_End";
+}
+
+class _ZLibInflateFilter extends _FilterImpl {
+  _ZLibInflateFilter(int windowBits, List<int> dictionary, bool raw) {
+    _init(windowBits, dictionary, raw);
+  }
+  void _init(int windowBits, List<int> dictionary, bool raw)
+      native "Filter_CreateZLibInflate";
+}
+
+class _ZLibDeflateFilter extends _FilterImpl {
+  _ZLibDeflateFilter(bool gzip, int level, int windowBits, int memLevel,
+                     int strategy, List<int> dictionary, bool raw) {
+    _init(gzip, level, windowBits, memLevel, strategy, dictionary, raw);
+  }
+  void _init(bool gzip, int level, int windowBits, int memLevel,
+             int strategy, List<int> dictionary, bool raw)
+      native "Filter_CreateZLibDeflate";
+}
+
+patch class _Filter {
+  /* patch */ static _Filter _newZLibDeflateFilter(bool gzip, int level,
+                                                   int windowBits, int memLevel,
+                                                   int strategy,
+                                                   List<int> dictionary,
+                                                   bool raw) =>
+      new _ZLibDeflateFilter(gzip, level, windowBits, memLevel, strategy,
+                             dictionary, raw);
+  /* patch */ static _Filter _newZLibInflateFilter(int windowBits,
+                                                   List<int> dictionary,
+                                                   bool raw) =>
+      new _ZLibInflateFilter(windowBits, dictionary, raw);
+}