Add a polyfill for CustomEvent.

Change-Id: I92ac840976794e62c6ffc18a2065d4ebc4dfb33c

lib/polyfill/all.js

@@ -20,6 +20,7 @@
 
 goog.provide('shaka.polyfill.installAll');
 
+goog.require('shaka.polyfill.CustomEvent');
 goog.require('shaka.polyfill.Fullscreen');
 goog.require('shaka.polyfill.MediaKeys');
 goog.require('shaka.polyfill.VideoPlaybackQuality');
@@ -36,6 +37,7 @@ goog.require('shaka.polyfill.VideoPlaybackQuality');
  * @export
  */
 shaka.polyfill.installAll = function() {
+  shaka.polyfill.CustomEvent.install();
   shaka.polyfill.Fullscreen.install();
   shaka.polyfill.MediaKeys.install();
   shaka.polyfill.VideoPlaybackQuality.install();

lib/polyfill/customevent.js

@@ -0,0 +1,68 @@
+/**
+ * Copyright 2015 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @fileoverview A polyfill to implement the CustomEvent constructor.
+ *
+ * @see http://enwp.org/polyfill
+ */
+
+goog.provide('shaka.polyfill.CustomEvent');
+
+
+/**
+ * @namespace shaka.polyfill.CustomEvent
+ * @export
+ *
+ * @summary A polyfill to implement the CustomEvent constructor on browsers
+ * which don't have one or don't allow its direct use.
+ */
+
+
+/**
+ * Install the polyfill if needed.
+ * @export
+ */
+shaka.polyfill.CustomEvent.install = function() {
+  var present = 'CustomEvent' in window;
+
+  if (present) {
+    try {
+      new CustomEvent('');
+    } catch (exception) {
+      present = false;
+    }
+  }
+
+  if (!present) {
+    window['CustomEvent'] = shaka.polyfill.CustomEvent.ctor_;
+  }
+};
+
+
+
+/**
+ * @this {CustomEvent}
+ * @constructor
+ * @param {string} type
+ * @param {CustomEventInit=} opt_init
+ * @private
+ */
+shaka.polyfill.CustomEvent.ctor_ = function(type, opt_init) {
+  var event = /** @type {!CustomEvent} */(document.createEvent('CustomEvent'));
+  var init = opt_init || { bubbles: false, cancelable: false, detail: null };
+  event.initCustomEvent(type, !!init.bubbles, !!init.cancelable, init.detail);
+  return event;
+};
+

support.js

@@ -59,10 +59,13 @@ var found = {};
 var async = [];
 
 // Find an entry in the report by name, then change its status to "bad".
-function markAsBad(name) {
+function markAsBad(name, opt_newValue) {
   for (var i = 0; i < report.length; ++i) {
     if (report[i][0] == name) {
       report[i][1] = kBad;
+      if (opt_newValue !== undefined) {
+        report[i][2] = opt_newValue;
+      }
       return;
     }
   }
@@ -96,21 +99,38 @@ function testFor(parent, name, required, boolValue, prefixes, prefixFn) {
 function testForClass(parent, name, required) {
   testFor(parent, name, required, false, classPrefixes,
           function(prefix, name) {
-              return prefix + name;
+            return prefix + name;
           });
 }
 
+function testForClassUsable(parent, name, required, args) {
+  testForClass(parent, name, required);
+  var ctor = found[name];
+  if (ctor) {
+    try {
+      // Some native DOM object constructors cannot be called without new.
+      // So in order to apply args, they must be bound.
+      var bindArgs = [ null ].concat(args);
+      var boundCtor = ctor.bind.apply(ctor, bindArgs);
+      new boundCtor();
+    } catch (exception) {
+      found[name] = false;
+      markAsBad(name, '(not usable)');
+    }
+  }
+}
+
 function testForMethod(parent, name, required) {
   testFor(parent, name, required, false, propertyPrefixes,
           function(prefix, name) {
-              return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+            return prefix + name.charAt(0).toUpperCase() + name.slice(1);
           });
 }
 
 function testForProperty(parent, name, required) {
   testFor(parent, name, required, true, propertyPrefixes,
           function(prefix, name) {
-              return prefix + name.charAt(0).toUpperCase() + name.slice(1);
+            return prefix + name.charAt(0).toUpperCase() + name.slice(1);
           });
 }
 
@@ -216,7 +236,9 @@ testForProperty(document, 'children', true);
 testForClass(window, 'VTTCue', false);
 testForProperty(document, 'fullscreenElement', false);
 testForProperty(document, 'fullScreenElement', false);
+testForClassUsable(window, 'CustomEvent', true, ['']);
 
+// Codecs:
 testForMimeType(vp8Type);
 testForMimeType(vp9Type);
 testForMimeType(mp4Type);
@@ -304,7 +326,7 @@ function onAsyncComplete() {
                       found[fairPlayId];
   var fullscreenApi = found['fullscreenElement'] || found['fullScreenElement'];
   var requiresPolyfills = !latestEme || !found['getVideoPlaybackQuality'] ||
-                          !document.fullscreenElement;
+                          !document.fullscreenElement || !found['CustomEvent'];
 
   var emeStatus, emeValue;
   if (emeApi && anyKeySystems) {