Use dart:html prefixes (e.g. webkitAudioNode) on other browsers

pkg/dev_compiler/lib/js/legacy/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 117 matching lines @@
     // 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();
+        let audioContext;
+        if (typeof AudioContext == "undefined" &&
+            (typeof webkitAudioContext != "undefined")) {
+          audioContext = new webkitAudioContext();
+        } else {
+          audioContext = new AudioContext();
+          window.StereoPannerNode =
+              audioContext.createStereoPanner().constructor;
+        }
         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 window.performance.memory != "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 d.animate != "undefined") {
+          window.Animation = d.animate(d).constructor;
+        }
       }
       if (typeof SourceBufferList == "undefined") {
         window.SourceBufferList = new MediaSource().sourceBuffers.constructor;
       }
     }
 
     // This import is only needed for chrome debugging. We should provide an
     // option to compile without it.
     dart_sdk._debugger.registerDevtoolsFormatter();
   }
 
 })(dart_library);