Only support unprefixed orientation API

Prefixed versions of the screen orientation API are not compatible
with the unprefixed version.  Until there is demand for prefixed
versions, only use the unprefixed version (Chrome & Firefox).
Prefixed versions should be supported through a polyfill, if at all.

This also fixes a bug in the demo app that caused the screen
orientation exception to be silently ignored.

Closes #1111

Change-Id: I9a6e963e6312983bc4bf629ecb2b8e1ad782c49c

demo/common/controls.js

@@ -193,9 +193,8 @@ ShakaControls.prototype.init = function(castProxy, onError, notifyCastStatus) {
   this.castProxy_.addEventListener(
       'caststatuschanged', this.onCastStatusChange_.bind(this));
 
-  var screenOrientation = this.getScreenOrientation_();
-  if (screenOrientation) {
-    screenOrientation.addEventListener(
+  if (screen.orientation) {
+    screen.orientation.addEventListener(
         'change', this.onScreenRotation_.bind(this));
   }
 };
@@ -208,31 +207,20 @@ ShakaControls.prototype.init = function(castProxy, onError, notifyCastStatus) {
  * @private
  */
 ShakaControls.prototype.onScreenRotation_ = function() {
-  var orientation = this.getScreenOrientation_();
-  if (!this.video_ || this.video_.readyState == 0 || !orientation ||
+  if (!this.video_ ||
+      this.video_.readyState == 0 ||
       this.castProxy_.isCasting()) return;
-  if (orientation.type.indexOf('landscape') >= 0 &&
+
+  if (screen.orientation.type.indexOf('landscape') >= 0 &&
       !document.fullscreenElement) {
     this.videoContainer_.requestFullscreen();
-  } else if (orientation.type.indexOf('portrait') >= 0 &&
+  } else if (screen.orientation.type.indexOf('portrait') >= 0 &&
       document.fullscreenElement) {
     document.exitFullscreen();
   }
 };
 
 
-/**
- * Get screen orientation.
- * Screen Orientation is implemented with a prefix for some browsers.
- * https://developer.mozilla.org/en-US/docs/Web/API/Screen/orientation
- * @return {?ScreenOrientation}
- * @private
- */
-ShakaControls.prototype.getScreenOrientation_ = function() {
-  return screen.orientation || screen.mozOrientation || screen.msOrientation;
-};
-
-
 /**
  * Initializes minimal player controls.  Used on both sender (indirectly) and
  * receiver (directly).

demo/main.js

@@ -209,6 +209,10 @@ shakaDemo.init = function() {
         shakaDemo.postBrowserCheckParams_(params);
         window.addEventListener('hashchange', shakaDemo.updateFromHash_);
       });
+    }).catch(function(error) {
+      // Some part of the setup of the demo app threw an error.
+      // Notify the user of this.
+      shakaDemo.onError_(/** @type {!shaka.util.Error} */ (error));
     });
   }
 };