media/test/data/eme_player_js/utils.js - cobalt - Git at Google

 // Copyright 2014 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 // Utils provide logging functions and other JS functions commonly used by the
 // app and media players.
 var Utils = new function() {
   this.titleChanged = false;
 };

 // Adds options to document element.
 Utils.addOptions = function(elementID, keyValueOptions, disabledOptions) {
   disabledOptions = disabledOptions || [];
   var selectElement = document.getElementById(elementID);
   var keys = Object.keys(keyValueOptions);
   for (var i = 0; i < keys.length; i++) {
     var key = keys[i];
     var option = new Option(key, keyValueOptions[key]);
     option.title = keyValueOptions[key];
     if (disabledOptions.indexOf(key) >= 0)
       option.disabled = true;
     selectElement.options.add(option);
   }
 };

 Utils.convertToArray = function(input) {
   if (Array.isArray(input))
     return input;
   return [input];
 };

 Utils.convertToUint8Array = function(msg) {
   if (typeof msg == 'string') {
     var ans = new Uint8Array(msg.length);
     for (var i = 0; i < msg.length; i++) {
       ans[i] = msg.charCodeAt(i);
     }
     return ans;
   }
   // Assume it is an ArrayBuffer or ArrayBufferView. If it already is a
   // Uint8Array, this will just make a copy of the view.
   return new Uint8Array(msg);
 };

 // Encodes data (Uint8Array) into base64url string. There is no '=' padding,
 // and the characters '-' and '_' must be used instead of '+' and '/',
 // respectively.
 Utils.base64urlEncode = function(data) {
   var result = btoa(String.fromCharCode.apply(null, data));
   return result.replace(/=+$/g, '').replace(/\+/g, '-').replace(/\//g, '_');
 };

 Utils.createJWKData = function(keyId, key) {
   // JWK routines copied from third_party/WebKit/LayoutTests/media/
   //   encrypted-media/encrypted-media-utils.js

   // Creates a JWK from raw key ID and key.
   function createJWK(keyId, key) {
     var jwk = '{"kty":"oct","kid":"';
     jwk += Utils.base64urlEncode(Utils.convertToUint8Array(keyId));
     jwk += '","k":"';
     jwk += Utils.base64urlEncode(Utils.convertToUint8Array(key));
     jwk += '"}';
     return jwk;
   }

   // Creates a JWK Set from an array of JWK(s).
   function createJWKSet() {
     var jwkSet = '{"keys":[';
     for (var i = 0; i < arguments.length; i++) {
       if (i != 0)
         jwkSet += ',';
       jwkSet += arguments[i];
     }
     jwkSet += '], "type":"temporary"}';
     return jwkSet;
   }

   return Utils.convertToUint8Array(createJWKSet(createJWK(keyId, key)));
 };

 Utils.createKeyIdsInitializationData = function(keyId) {
   var initData = '{"kids":["';
   initData += Utils.base64urlEncode(Utils.convertToUint8Array(keyId));
   initData += '"]}';
   return Utils.convertToUint8Array(initData);
 };

 function convertToString(data) {
   return String.fromCharCode.apply(null, Utils.convertToUint8Array(data));
 }

 Utils.extractFirstLicenseKeyId = function(message) {
   // Decodes data (Uint8Array) from base64url string.
   function base64urlDecode(data) {
     return atob(data.replace(/\-/g, "+").replace(/\_/g, "/"));
   }

   try {
     var json = JSON.parse(convertToString(message));
     // Decode the first element of 'kids', return it as an Uint8Array.
     return Utils.convertToUint8Array(base64urlDecode(json.kids[0]));
   } catch (error) {
     // Not valid JSON, so return message untouched as Uint8Array.
     return Utils.convertToUint8Array(message);
   }
 };

 Utils.verifyUsageRecord =
     function(message, expectNullTime) {
   try {
     var json = JSON.parse(convertToString(message));
     if (expectNullTime && (json.firstTime != null || json.latestTime != null)) {
       Utils.failTest(
           'Expecting null time for usage record but got firstTime=' +
           json.firstTime + ', latestTime=' + json.latestTime);
     } else if (!expectNullTime) {
       var first_decrypt_time = new Date(json.firstTime);
       var last_decrypt_time = new Date(json.latestTime);
       Utils.timeLog('First decrypt time: ' + first_decrypt_time.toISOString());
       Utils.timeLog('Last decrypt time: ' + last_decrypt_time.toISOString());

       var delta = json.latestTime - json.firstTime;
       // The video used for the tests is roughly 2.5 seconds.
       if (delta < 2000 || delta > 3000) {
         Utils.failTest(
             'The usage record reported by the CDM was not in the ' +
             'expected range')
       }
     }

   } catch (error) {
     Utils.failTest(
         'Fail to extract first decrypt time from license-release' +
         'message');
   }
 }

     Utils.documentLog = function(log, success, time) {
   if (!docLogs)
     return;
   time = time || Utils.getCurrentTimeString();
   var timeLog = '<span style="color: green">' + time + '</span>';
   var logColor = !success ? 'red' : 'black'; // default is true.
   log = '<span style="color: "' + logColor + '>' + log + '</span>';
   docLogs.innerHTML = timeLog + ' - ' + log + '<br>' + docLogs.innerHTML;
 };

 Utils.ensureOptionInList = function(listID, option) {
   var selectElement = document.getElementById(listID);
   for (var i = 0; i < selectElement.length; i++) {
     if (selectElement.options[i].value == option) {
       selectElement.value = option;
       return;
     }
   }
   // The list does not have the option, let's add it and select it.
   var optionElement = new Option(option, option);
   optionElement.title = option;
   selectElement.options.add(optionElement);
   selectElement.value = option;
 };

 Utils.failTest = function(msg, newTitle) {
   var failMessage = 'FAIL: ';
   var title = 'FAILED';
   // Handle exception messages;
   if (msg.message) {
     title = msg.name || 'Error';
     failMessage += title + ' ' + msg.message;
   } else if (msg instanceof Event) {
     // Handle failing events.
     failMessage = msg.target + '.' + msg.type;
     title = msg.type;
   } else {
     failMessage += msg;
   }
   // Force newTitle if passed.
   title = newTitle || title;
   // Log failure.
   Utils.documentLog(failMessage, false);
   console.log(failMessage, msg);
   Utils.setResultInTitle(title);
 };

 Utils.getCurrentTimeString = function() {
   var date = new Date();
   var hours = ('0' + date.getHours()).slice(-2);
   var minutes = ('0' + date.getMinutes()).slice(-2);
   var secs = ('0' + date.getSeconds()).slice(-2);
   var milliSecs = ('00' + date.getMilliseconds()).slice(-3);
   return hours + ':' + minutes + ':' + secs + '.' + milliSecs;
 };

 Utils.getDefaultKey = function(forceInvalidResponse) {
   if (forceInvalidResponse) {
     Utils.timeLog('Forcing invalid key data.');
     return new Uint8Array([0xAA]);
   }
   return KEY;
 };

 Utils.getHexString = function(uintArray) {
   var hex_str = '';
   for (var i = 0; i < uintArray.length; i++) {
     var hex = uintArray[i].toString(16);
     if (hex.length == 1)
       hex = '0' + hex;
     hex_str += hex;
   }
   return hex_str;
 };

 Utils.hasPrefix = function(msg, prefix) {
   var message = String.fromCharCode.apply(null, Utils.convertToUint8Array(msg));
   return message.substring(0, prefix.length) == prefix;
 };

 Utils.installTitleEventHandler = function(element, event) {
   element.addEventListener(event, function(e) {
     Utils.setResultInTitle(e.type.toUpperCase());
   }, false);
 };

 Utils.resetTitleChange = function() {
   this.titleChanged = false;
   document.title = '';
 };

 Utils.sendRequest = function(
     requestType, responseType, message, serverURL, onResponseCallbackFn,
     forceInvalidResponse) {
   var requestAttemptCount = 0;
   var REQUEST_RETRY_DELAY_MS = 3000;
   var REQUEST_TIMEOUT_MS = 1000;

   function sendRequestAttempt() {
     // No limit on the number of retries. This will retry on failures
     // until the test framework stops the test.
     requestAttemptCount++;
     var xmlhttp = new XMLHttpRequest();
     xmlhttp.responseType = responseType;
     xmlhttp.open(requestType, serverURL, true);
     xmlhttp.onerror = function(e) {
       Utils.timeLog('Request status: ' + this.statusText);
       Utils.timeLog('FAILED: License request XHR failed with network error.');
       Utils.timeLog('Retrying request in ' + REQUEST_RETRY_DELAY_MS + 'ms');
       setTimeout(sendRequestAttempt, REQUEST_RETRY_DELAY_MS);
     };
     xmlhttp.onload = function(e) {
       if (this.status == 200) {
         onResponseCallbackFn(this.response);
       } else if (this.status == 404 && serverURL == DEFAULT_LICENSE_SERVER) {
         // If using the default license server, no page available means there
         // is no license server configured.
         onResponseCallbackFn(Utils.convertToUint8Array("No license."));
       } else {
         Utils.timeLog('Bad response status: ' + this.status);
         Utils.timeLog('Bad response: ' + this.response);
         Utils.timeLog('Retrying request in ' + REQUEST_RETRY_DELAY_MS + 'ms');
         setTimeout(sendRequestAttempt, REQUEST_RETRY_DELAY_MS);
       }
     };
     xmlhttp.timeout = REQUEST_TIMEOUT_MS;
     xmlhttp.ontimeout = function(e) {
       Utils.timeLog('Request timeout');
       Utils.timeLog('Retrying request in ' + REQUEST_RETRY_DELAY_MS + 'ms');
       setTimeout(sendRequestAttempt, REQUEST_RETRY_DELAY_MS);
     }
     Utils.timeLog('Attempt (' + requestAttemptCount +
                   '): sending request to server: ' + serverURL);
     xmlhttp.send(message);
   }

   if (forceInvalidResponse) {
     Utils.timeLog('Not sending request - forcing an invalid response.');
     return onResponseCallbackFn(Utils.convertToUint8Array("Invalid response."));
   }
   sendRequestAttempt();
 };

 Utils.setResultInTitle = function(title) {
   // If document title is 'ENDED', then update it with new title to possibly
   // mark a test as failure.  Otherwise, keep the first title change in place.
   if (!this.titleChanged || document.title == 'ENDED')
     document.title = title;
   Utils.timeLog('Set document title to: ' + title + ', updated title: ' +
                 document.title);
   this.titleChanged = true;
 };

 Utils.timeLog = function(/**/) {
   if (arguments.length == 0)
     return;
   var time = Utils.getCurrentTimeString();
   // Log to document.
   Utils.documentLog(arguments[0], time);
   // Log to JS console.
   var logString = time + ' - ';
   for (var i = 0; i < arguments.length; i++) {
     logString += ' ' + arguments[i];
   }
   console.log(logString);
 };

 // Convert an event into a promise. When |event| is fired on |object|,
 // call |func| to handle the event and either resolve or reject the promise.
 // If |func| is not specified, the promise will simply be resolved with the
 // event when the event happens.
 Utils.waitForEvent = function(object, event, func) {
   return new Promise(function(resolve, reject) {
     object.addEventListener(event, function listener(e) {
       object.removeEventListener(event, listener);
       if (func) {
         func(e, resolve, reject);
       } else {
         // No |func| is specified, so simply resolve the promise passing
         // |event| in case the caller is interested in it.
         resolve(event);
       }
     });
   });
 };

 // Create a loadable session and return the session ID of it as a promise.
 Utils.createSessionToLoad = function(mediaKeys, request) {
   // Create a persistent session and on the message event initialize it
   // with key ID |KEY_ID| and key |KEY|. Then close the session, and resolve
   // the promise providing the session ID.
   const keySession = mediaKeys.createSession('persistent-license');
   var promise =
       Utils.waitForEvent(keySession, 'message', function(e, resolve, reject) {
         const session = e.target;
         return session.update(Utils.createJWKData(KEY_ID, KEY))
             .then(function(result) {
               Utils.timeLog(
                   'Persistent session ' + session.sessionId + ' created');
               return session.close();
             })
             .then(function(result) {
               // Make sure the session is properly closed before continuing on.
               return session.closed;
             })
             .then(function(result) {
               Utils.timeLog(
                   'Persistent session ' + session.sessionId +
                   ' saved and closed');
               resolve(session.sessionId);
             });
       });
   return keySession
       .generateRequest('keyids', Utils.createKeyIdsInitializationData(KEY_ID))
       .then(function() {
         return promise;
       });
 };

 // Verify that |keyStatuses| contains just the keys in the array |expected|.
 // Each entry specifies the keyId and status expected.
 // Example call: verifyKeyStatuses(mediaKeySession.keyStatuses,
 //   [{keyId: key1, status: 'usable'}, {keyId: key2, status: 'released'}]);
 Utils.verifyKeyStatuses = function(keyStatuses, expected) {
   // |keyStatuses| should have same size as number of |keys.expected|.
   if (keyStatuses.size !== expected.length) {
     Utils.failTest(
         'keystatuses should have expected size of ' + expected.length +
         ' but has size ' + keyStatuses.size);
   }

   // All |expected| should be found.
   expected.map(function(item) {
     if (!keyStatuses.has(Utils.convertToUint8Array(item.keyId))) {
       Utils.failTest('missing keyID ' + item.keyId);
     }
     if (keyStatuses.get(Utils.convertToUint8Array(item.keyId)) !==
         item.status) {
       Utils.failTest(
           'keyId ' + item.keyId + ' has status ' +
           keyStatuses.get(Utils.convertToUint8Array(item.keyId)) +
           ', expected ' + item.status);
     }
   });
 };
	// Copyright 2014 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	// Utils provide logging functions and other JS functions commonly used by the
	// app and media players.
	var Utils = new function() {
	this.titleChanged = false;
	};

	// Adds options to document element.
	Utils.addOptions = function(elementID, keyValueOptions, disabledOptions) {
	disabledOptions = disabledOptions \|\| [];
	var selectElement = document.getElementById(elementID);
	var keys = Object.keys(keyValueOptions);
	for (var i = 0; i < keys.length; i++) {
	var key = keys[i];
	var option = new Option(key, keyValueOptions[key]);
	option.title = keyValueOptions[key];
	if (disabledOptions.indexOf(key) >= 0)
	option.disabled = true;
	selectElement.options.add(option);
	}
	};

	Utils.convertToArray = function(input) {
	if (Array.isArray(input))
	return input;
	return [input];
	};

	Utils.convertToUint8Array = function(msg) {
	if (typeof msg == 'string') {
	var ans = new Uint8Array(msg.length);
	for (var i = 0; i < msg.length; i++) {
	ans[i] = msg.charCodeAt(i);
	}
	return ans;
	}
	// Assume it is an ArrayBuffer or ArrayBufferView. If it already is a
	// Uint8Array, this will just make a copy of the view.
	return new Uint8Array(msg);
	};

	// Encodes data (Uint8Array) into base64url string. There is no '=' padding,
	// and the characters '-' and '_' must be used instead of '+' and '/',
	// respectively.
	Utils.base64urlEncode = function(data) {
	var result = btoa(String.fromCharCode.apply(null, data));
	return result.replace(/=+$/g, '').replace(/\+/g, '-').replace(/\//g, '_');
	};

	Utils.createJWKData = function(keyId, key) {
	// JWK routines copied from third_party/WebKit/LayoutTests/media/
	// encrypted-media/encrypted-media-utils.js

	// Creates a JWK from raw key ID and key.
	function createJWK(keyId, key) {
	var jwk = '{"kty":"oct","kid":"';
	jwk += Utils.base64urlEncode(Utils.convertToUint8Array(keyId));
	jwk += '","k":"';
	jwk += Utils.base64urlEncode(Utils.convertToUint8Array(key));
	jwk += '"}';
	return jwk;
	}

	// Creates a JWK Set from an array of JWK(s).
	function createJWKSet() {
	var jwkSet = '{"keys":[';
	for (var i = 0; i < arguments.length; i++) {
	if (i != 0)
	jwkSet += ',';
	jwkSet += arguments[i];
	}
	jwkSet += '], "type":"temporary"}';
	return jwkSet;
	}

	return Utils.convertToUint8Array(createJWKSet(createJWK(keyId, key)));
	};

	Utils.createKeyIdsInitializationData = function(keyId) {
	var initData = '{"kids":["';
	initData += Utils.base64urlEncode(Utils.convertToUint8Array(keyId));
	initData += '"]}';
	return Utils.convertToUint8Array(initData);
	};

	function convertToString(data) {
	return String.fromCharCode.apply(null, Utils.convertToUint8Array(data));
	}

	Utils.extractFirstLicenseKeyId = function(message) {
	// Decodes data (Uint8Array) from base64url string.
	function base64urlDecode(data) {
	return atob(data.replace(/\-/g, "+").replace(/\_/g, "/"));
	}

	try {
	var json = JSON.parse(convertToString(message));
	// Decode the first element of 'kids', return it as an Uint8Array.
	return Utils.convertToUint8Array(base64urlDecode(json.kids[0]));
	} catch (error) {
	// Not valid JSON, so return message untouched as Uint8Array.
	return Utils.convertToUint8Array(message);
	}
	};

	Utils.verifyUsageRecord =
	function(message, expectNullTime) {
	try {
	var json = JSON.parse(convertToString(message));
	if (expectNullTime && (json.firstTime != null \|\| json.latestTime != null)) {
	Utils.failTest(
	'Expecting null time for usage record but got firstTime=' +
	json.firstTime + ', latestTime=' + json.latestTime);
	} else if (!expectNullTime) {
	var first_decrypt_time = new Date(json.firstTime);
	var last_decrypt_time = new Date(json.latestTime);
	Utils.timeLog('First decrypt time: ' + first_decrypt_time.toISOString());
	Utils.timeLog('Last decrypt time: ' + last_decrypt_time.toISOString());

	var delta = json.latestTime - json.firstTime;
	// The video used for the tests is roughly 2.5 seconds.
	if (delta < 2000 \|\| delta > 3000) {
	Utils.failTest(
	'The usage record reported by the CDM was not in the ' +
	'expected range')
	}
	}

	} catch (error) {
	Utils.failTest(
	'Fail to extract first decrypt time from license-release' +
	'message');
	}
	}

	Utils.documentLog = function(log, success, time) {
	if (!docLogs)
	return;
	time = time \|\| Utils.getCurrentTimeString();
	var timeLog = '<span style="color: green">' + time + '</span>';
	var logColor = !success ? 'red' : 'black'; // default is true.
	log = '<span style="color: "' + logColor + '>' + log + '</span>';
	docLogs.innerHTML = timeLog + ' - ' + log + '<br>' + docLogs.innerHTML;
	};

	Utils.ensureOptionInList = function(listID, option) {
	var selectElement = document.getElementById(listID);
	for (var i = 0; i < selectElement.length; i++) {
	if (selectElement.options[i].value == option) {
	selectElement.value = option;
	return;
	}
	}
	// The list does not have the option, let's add it and select it.
	var optionElement = new Option(option, option);
	optionElement.title = option;
	selectElement.options.add(optionElement);
	selectElement.value = option;
	};

	Utils.failTest = function(msg, newTitle) {
	var failMessage = 'FAIL: ';
	var title = 'FAILED';
	// Handle exception messages;
	if (msg.message) {
	title = msg.name \|\| 'Error';
	failMessage += title + ' ' + msg.message;
	} else if (msg instanceof Event) {
	// Handle failing events.
	failMessage = msg.target + '.' + msg.type;
	title = msg.type;
	} else {
	failMessage += msg;
	}
	// Force newTitle if passed.
	title = newTitle \|\| title;
	// Log failure.
	Utils.documentLog(failMessage, false);
	console.log(failMessage, msg);
	Utils.setResultInTitle(title);
	};

	Utils.getCurrentTimeString = function() {
	var date = new Date();
	var hours = ('0' + date.getHours()).slice(-2);
	var minutes = ('0' + date.getMinutes()).slice(-2);
	var secs = ('0' + date.getSeconds()).slice(-2);
	var milliSecs = ('00' + date.getMilliseconds()).slice(-3);
	return hours + ':' + minutes + ':' + secs + '.' + milliSecs;
	};

	Utils.getDefaultKey = function(forceInvalidResponse) {
	if (forceInvalidResponse) {
	Utils.timeLog('Forcing invalid key data.');
	return new Uint8Array([0xAA]);
	}
	return KEY;
	};

	Utils.getHexString = function(uintArray) {
	var hex_str = '';
	for (var i = 0; i < uintArray.length; i++) {
	var hex = uintArray[i].toString(16);
	if (hex.length == 1)
	hex = '0' + hex;
	hex_str += hex;
	}
	return hex_str;
	};

	Utils.hasPrefix = function(msg, prefix) {
	var message = String.fromCharCode.apply(null, Utils.convertToUint8Array(msg));
	return message.substring(0, prefix.length) == prefix;
	};

	Utils.installTitleEventHandler = function(element, event) {
	element.addEventListener(event, function(e) {
	Utils.setResultInTitle(e.type.toUpperCase());
	}, false);
	};

	Utils.resetTitleChange = function() {
	this.titleChanged = false;
	document.title = '';
	};

	Utils.sendRequest = function(
	requestType, responseType, message, serverURL, onResponseCallbackFn,
	forceInvalidResponse) {
	var requestAttemptCount = 0;
	var REQUEST_RETRY_DELAY_MS = 3000;
	var REQUEST_TIMEOUT_MS = 1000;

	function sendRequestAttempt() {
	// No limit on the number of retries. This will retry on failures
	// until the test framework stops the test.
	requestAttemptCount++;
	var xmlhttp = new XMLHttpRequest();
	xmlhttp.responseType = responseType;
	xmlhttp.open(requestType, serverURL, true);
	xmlhttp.onerror = function(e) {
	Utils.timeLog('Request status: ' + this.statusText);
	Utils.timeLog('FAILED: License request XHR failed with network error.');
	Utils.timeLog('Retrying request in ' + REQUEST_RETRY_DELAY_MS + 'ms');
	setTimeout(sendRequestAttempt, REQUEST_RETRY_DELAY_MS);
	};
	xmlhttp.onload = function(e) {
	if (this.status == 200) {
	onResponseCallbackFn(this.response);
	} else if (this.status == 404 && serverURL == DEFAULT_LICENSE_SERVER) {
	// If using the default license server, no page available means there
	// is no license server configured.
	onResponseCallbackFn(Utils.convertToUint8Array("No license."));
	} else {
	Utils.timeLog('Bad response status: ' + this.status);
	Utils.timeLog('Bad response: ' + this.response);
	Utils.timeLog('Retrying request in ' + REQUEST_RETRY_DELAY_MS + 'ms');
	setTimeout(sendRequestAttempt, REQUEST_RETRY_DELAY_MS);
	}
	};
	xmlhttp.timeout = REQUEST_TIMEOUT_MS;
	xmlhttp.ontimeout = function(e) {
	Utils.timeLog('Request timeout');
	Utils.timeLog('Retrying request in ' + REQUEST_RETRY_DELAY_MS + 'ms');
	setTimeout(sendRequestAttempt, REQUEST_RETRY_DELAY_MS);
	}
	Utils.timeLog('Attempt (' + requestAttemptCount +
	'): sending request to server: ' + serverURL);
	xmlhttp.send(message);
	}

	if (forceInvalidResponse) {
	Utils.timeLog('Not sending request - forcing an invalid response.');
	return onResponseCallbackFn(Utils.convertToUint8Array("Invalid response."));
	}
	sendRequestAttempt();
	};

	Utils.setResultInTitle = function(title) {
	// If document title is 'ENDED', then update it with new title to possibly
	// mark a test as failure. Otherwise, keep the first title change in place.
	if (!this.titleChanged \|\| document.title == 'ENDED')
	document.title = title;
	Utils.timeLog('Set document title to: ' + title + ', updated title: ' +
	document.title);
	this.titleChanged = true;
	};

	Utils.timeLog = function(/**/) {
	if (arguments.length == 0)
	return;
	var time = Utils.getCurrentTimeString();
	// Log to document.
	Utils.documentLog(arguments[0], time);
	// Log to JS console.
	var logString = time + ' - ';
	for (var i = 0; i < arguments.length; i++) {
	logString += ' ' + arguments[i];
	}
	console.log(logString);
	};

	// Convert an event into a promise. When \|event\| is fired on \|object\|,
	// call \|func\| to handle the event and either resolve or reject the promise.
	// If \|func\| is not specified, the promise will simply be resolved with the
	// event when the event happens.
	Utils.waitForEvent = function(object, event, func) {
	return new Promise(function(resolve, reject) {
	object.addEventListener(event, function listener(e) {
	object.removeEventListener(event, listener);
	if (func) {
	func(e, resolve, reject);
	} else {
	// No \|func\| is specified, so simply resolve the promise passing
	// \|event\| in case the caller is interested in it.
	resolve(event);
	}
	});
	});
	};

	// Create a loadable session and return the session ID of it as a promise.
	Utils.createSessionToLoad = function(mediaKeys, request) {
	// Create a persistent session and on the message event initialize it
	// with key ID \|KEY_ID\| and key \|KEY\|. Then close the session, and resolve
	// the promise providing the session ID.
	const keySession = mediaKeys.createSession('persistent-license');
	var promise =
	Utils.waitForEvent(keySession, 'message', function(e, resolve, reject) {
	const session = e.target;
	return session.update(Utils.createJWKData(KEY_ID, KEY))
	.then(function(result) {
	Utils.timeLog(
	'Persistent session ' + session.sessionId + ' created');
	return session.close();
	})
	.then(function(result) {
	// Make sure the session is properly closed before continuing on.
	return session.closed;
	})
	.then(function(result) {
	Utils.timeLog(
	'Persistent session ' + session.sessionId +
	' saved and closed');
	resolve(session.sessionId);
	});
	});
	return keySession
	.generateRequest('keyids', Utils.createKeyIdsInitializationData(KEY_ID))
	.then(function() {
	return promise;
	});
	};

	// Verify that \|keyStatuses\| contains just the keys in the array \|expected\|.
	// Each entry specifies the keyId and status expected.
	// Example call: verifyKeyStatuses(mediaKeySession.keyStatuses,
	// [{keyId: key1, status: 'usable'}, {keyId: key2, status: 'released'}]);
	Utils.verifyKeyStatuses = function(keyStatuses, expected) {
	// \|keyStatuses\| should have same size as number of \|keys.expected\|.
	if (keyStatuses.size !== expected.length) {
	Utils.failTest(
	'keystatuses should have expected size of ' + expected.length +
	' but has size ' + keyStatuses.size);
	}

	// All \|expected\| should be found.
	expected.map(function(item) {
	if (!keyStatuses.has(Utils.convertToUint8Array(item.keyId))) {
	Utils.failTest('missing keyID ' + item.keyId);
	}
	if (keyStatuses.get(Utils.convertToUint8Array(item.keyId)) !==
	item.status) {
	Utils.failTest(
	'keyId ' + item.keyId + ' has status ' +
	keyStatuses.get(Utils.convertToUint8Array(item.keyId)) +
	', expected ' + item.status);
	}
	});
	};