Revert "Revert "Blob constructor""

lib/html/dartium/html_dartium.dart

Index: lib/html/dartium/html_dartium.dart
diff --git a/lib/html/dartium/html_dartium.dart b/lib/html/dartium/html_dartium.dart
index a028ffcc44cb469ddfe5db40fb34c6dc5033ac4a..531b3558ba14d56dc4cc1a9351838d18d65c299f 100644
--- a/lib/html/dartium/html_dartium.dart
+++ b/lib/html/dartium/html_dartium.dart
@@ -646,6 +646,14 @@ class _BiquadFilterNodeImpl extends _AudioNodeImpl implements BiquadFilterNode {
 // 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 _BlobFactoryProvider {
+  factory Blob(List blobParts, [String type = null, String endings = null]) => _createBlob(blobParts, type, endings);
+  static Blob _createBlob(List blobParts, [String type = null, String endings = null]) native "Blob_constructor_Callback";
+}
+// Copyright (c) 2012, 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.
+
 // WARNING: Do not edit - generated code.
 
 class _BlobImpl extends NativeFieldWrapperClass1 implements Blob {
@@ -22310,7 +22318,9 @@ interface BiquadFilterNode extends AudioNode {
 // WARNING: Do not edit - generated code.
 
 /// @domName Blob
-interface Blob {
+interface Blob default _BlobFactoryProvider {
+
+  Blob(List blobParts, [String type, String endings]);
 
   /** @domName Blob.size */
   final int size;