Add JSNative utility class with static methods methods to efficiently manipulate typed JSInterop ob…

sdk/lib/_internal/sdk_library_metadata/lib/libraries.dart

 // 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.
 
 library libraries;
 
 /**
  * A bit flag used by [LibraryInfo] indicating that a library is used by dart2js
  */
 const int DART2JS_PLATFORM = 1;
@@ skipping 98 matching lines @@
       categories: "Client,Server",
       maturity: Maturity.STABLE,
       dart2jsPatchPath: "_internal/js_runtime/lib/isolate_patch.dart"),
 
   "js": const LibraryInfo(
       "js/dartium/js_dartium.dart",
       categories: "Client",
       maturity: Maturity.STABLE,
       dart2jsPath: "js/dart2js/js_dart2js.dart"),
 
+  "js_util": const LibraryInfo(
+      "js_util/dartium/js_util_dartium.dart",
+      categories: "Client",
+      maturity: Maturity.STABLE,
+      dart2jsPath: "js_util/dart2js/js_util_dart2js.dart"),
+
   "math": const LibraryInfo(
       "math/math.dart",
       categories: "Client,Server,Embedded",
       maturity: Maturity.STABLE,
       dart2jsPatchPath: "_internal/js_runtime/lib/math_patch.dart"),
 
   "mirrors": const LibraryInfo(
       "mirrors/mirrors.dart",
       categories: "Client,Server",
       maturity: Maturity.UNSTABLE,
@@ skipping 242 matching lines @@
   static const Maturity STABLE = const Maturity(4, "Stable",
     "The library is stable. API backwards-compatibility is guaranteed.\n"
     "However implementation details might change.");
 
   static const Maturity LOCKED = const Maturity(5, "Locked",
     "This library will not change except when serious bugs are encountered.");
 
   static const Maturity UNSPECIFIED = const Maturity(-1, "Unspecified",
     "The maturity for this library has not been specified.");
 }