diff --git a/lib/polyfill/fullscreen.js b/lib/polyfill/fullscreen.js
index <HASH>..<HASH> 100644
--- a/lib/polyfill/fullscreen.js
+++ b/lib/polyfill/fullscreen.js
@@ -59,6 +59,13 @@ shaka.polyfill.Fullscreen.install = function() {
                document.webkitFullscreenElement;
       }
     });
+    Object.defineProperty(document, 'fullscreenEnabled', {
+      get: function() {
+        return document.mozFullScreenEnabled ||
+               document.msFullscreenEnabled ||
+               document.webkitFullscreenEnabled;
+      }
+    });
   }
 
   var proxy = shaka.polyfill.Fullscreen.proxyEvent_;
Expanded the fullscreen polyfill.

Now it includes fullscreenEnabled.

Closes #<I>

Change-Id: I7df3c<I>ecc<I>a<I>ba<I>ac<I>aae2bc9b<I>d5