Make Web Cryptography API available in Workers
See
@@ -813,3 +813,9 @@ webCrypto.Crypto.prototype.subtle;
* @type {!webCrypto.Crypto|undefined}
*/
var crypto;
+
+/**
+ * @type {!webCrypto.Crypto}
+ * @see https://www.w3.org/TR/WebCryptoAPI/#crypto-interface
+ */
+WorkerGlobalScope.prototype.crypto;
