Add W3C encrypted-media tests

third_party/WebKit/LayoutTests/imported/wpt/encrypted-media/polyfill/cast-polyfill.js

+(function() {
+
+    if ( /CrKey\/[0-9]+\.[0-9a-z]+\.[0-9a-z]+/i.exec( navigator.userAgent ) ) {
+
+        var castscript = document.createElement('script');
+        castscript.type = 'text/javascript';
+        castscript.src = 'https://www.gstatic.com/cast/sdk/libs/receiver/2.0.0/cast_receiver.js'
+        document.head.appendChild( castscript );
+
+        var _requestMediaKeySystemAccess = navigator.requestMediaKeySystemAccess.bind( navigator ),
+            _setMediaKeys = HTMLMediaElement.prototype.setMediaKeys,
+            _load = MediaKeySession.prototype.load;
+
+        MediaKeySession.prototype.load = function load()
+        {
+            return _load.call( this ).then( function( success )
+            {
+                return success ? this.remove() : false;
+            }.bind( this ) );
+        };
+
+        function MediaKeys( mediaKeys )
+        {
+            this._mediaKeys = mediaKeys;
+        }
+
+        MediaKeys.prototype.setServerCertificate = function setServerCertificate( certificate )
+        {
+            return this._mediaKeys.setServerCertificate( certificate );
+        };
+
+        MediaKeys.prototype.createSession = function createSession( sessionType ) {
+
+            if ( sessionType === 'persistent-usage-record' )
+            {
+                return cast.receiver.eme.KeySession.createSession( this._mediaKeys, 'persistent-release-message' );
+            }
+
+            return this._mediaKeys.createSession( sessionType );
+        };
+
+        function MediaKeySystemAccess( access )
+        {
+            this._access = mediaKeySystemAccess;
+        }
+
+        Object.defineProperty( MediaKeySystemAccess.prototype, 'keySystem', { get: function() { return this._access.keySystem; } } );
+
+        MediaKeySystemAccess.prototype.getConfiguration = function getConfiguration() { return this._access.getConfiguration(); };
+
+        MediaKeySystemAccess.prototype.createMediaKeys = function createMediaKeys() {
+
+            return this._access.createMediaKey().then( function( mediaKeys ) { return new MediaKeys( mediaKeys ); } );
+
+        };
+
+        HTMLMediaElement.prototype.setMediaKeys = function setMediaKeys( mediaKeys )
+        {
+            if ( mediaKeys instanceof MediaKeys )
+            {
+                return _setMediaKeys.call( this, mediaKeys._mediaKeys );
+            }
+            else
+            {
+                return _setMediaKeys.call( this, mediaKeys );
+            }
+        };
+
+        navigator.requestMediaKeySystemAccess = function requestMediaKeySystemAccess( keysystem, supportedConfigurations ) {
+
+            if ( keysystem !== 'com.chromecast.playready' )
+            {
+                return _requestMediaKeySystemAccess( keysystem, supportedConfigurations );
+            }
+
+            return _requestMediaKeySystemAccess( keysystem, supportedConfigurations )
+            .then( function( access ) { return new MediaKeySystemAccess( access ); } );
+        };
+    }
+})();