Add missing comma to libraries.dart

sdk/lib/_internal/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 14 matching lines @@
   "async": const LibraryInfo(
       "async/async.dart",
       maturity: Maturity.STABLE,
       dart2jsPatchPath: "_internal/lib/async_patch.dart"),
 
   "blink": const LibraryInfo(
       "blink/dartium/blink_dartium.dart",
       category: "Client",
       implementation: true,
       documented: false,
-      platforms: VM_PLATFORM)
+      platforms: VM_PLATFORM),
  
   "_chrome": const LibraryInfo(
       "_chrome/dart2js/chrome_dart2js.dart",
       documented: false,
       category: "Client"),
 
   "collection": const LibraryInfo(
       "collection/collection.dart",
       maturity: Maturity.STABLE,
       dart2jsPatchPath: "_internal/lib/collection_patch.dart"),
@@ skipping 262 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.");
 }