polyfill prototypes on window for important dart:html types where recent versions of Chrome hide th…

lib/runtime/dart_library.js

 // Copyright (c) 2015, 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.
 
 /* This file defines the module loader for the dart runtime.
 */
 
 var dart_library =
   typeof module != "undefined" && module.exports || {};
 
@@ skipping 97 matching lines @@
     // Force import of core.
     var dart_sdk = import_('dart_sdk');
 
     // TODO(vsm): DOM facades?
     // See: https://github.com/dart-lang/dev_compiler/issues/173
     if (typeof NodeList !== "undefined") {
       NodeList.prototype.get = function(i) { return this[i]; };
       NamedNodeMap.prototype.get = function(i) { return this[i]; };
       DOMTokenList.prototype.get = function(i) { return this[i]; };
       HTMLCollection.prototype.get = function(i) { return this[i]; };
+      // Expose constructors for DOM types dart:html needs to assume are
+      // available on window.
+      if (typeof PannerNode == "undefined") {
+        let audioContext = new AudioContext();
+        window.PannerNode = audioContext.createPanner().constructor;
+        window.StereoPannerNode = audioContext.createStereoPanner().constructor;
+      }
+      if (typeof AudioSourceNode == "undefined") {
+        window.AudioSourceNode = MediaElementAudioSourceNode.constructor;
+      }
+      if (typeof FontFaceSet == "undefined") {
+        window.FontFaceSet = document.fonts.__proto__.constructor;
+      }
+      if (typeof MemoryInfo == "undefined") {
+        window.MemoryInfo = window.performance.memory.constructor;
+      }
+      if (typeof Geolocation == "undefined") {
+        navigator.geolocation.constructor;
+      }
+      if (typeof Animation == "undefined") {
+        let d = document.createElement('div');
+        window.Animation = d.animate(d).constructor;
+      }
+      if (typeof WebGLVertexArrayObjectOES == "undefined") {
+        window.WebGLVertexArrayObjectOES = document.createElement('canvas')
+          .getContext('webgl')
+          .getExtension("OES_vertex_array_object")
+          .createVertexArrayOES().constructor;
+      }
     }
 
     // This import is only needed for chrome debugging. We should provide an
     // option to compile without it.
     dart_sdk._debugger.registerDevtoolsFormatter();
   }
 
 })(dart_library);