Use ASCII serialization for origins

This patch makes it to use ASCII serialization for
(Extendable)MessageEvent.origin instead of Unicode serialization which
has been removed from HTML.

HTML issue: whatwg/html#2568.
HTML change: whatwg/html@c3b2511.

Fixes #1142.

Author: jungkees

docs/index.bs

@@ -414,7 +414,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
                         <dt>Otherwise</dt>
                         <dd>a new {{Client}} object that represents |incumbentGlobal|'s associated worker
                     </dd>
-                1. Let |origin| be the [=Unicode serialization of an origin|Unicode serialization=] of |incumbentSettings|'s [=environment settings object/origin=].
+                1. Let |origin| be the [=serialization of an origin|serialization=] of |incumbentSettings|'s [=environment settings object/origin=].
                 1. Let |destination| be the {{ServiceWorkerGlobalScope}} object associated with |serviceWorker|.
                 1.  Let |deserializeRecord| be <a abstract-op>StructuredDeserializeWithTransfer</a>(|serializeWithTransferResult|, |destination|'s [=global object/Realm=]).
 
@@ -1106,7 +1106,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
             1. If |targetClient| is null, return.
             1. Let |destination| be the {{ServiceWorkerContainer}} object whose associated [=ServiceWorkerContainer/service worker client=] is |targetClient|.
             1. Add a [=task=] that runs the following steps to |destination|'s [=ServiceWorkerContainer/client message queue=]:
-                1. Let |origin| be the [=Unicode serialization of an origin|Unicode serialization=] of |sourceSettings|'s [=environment settings object/origin=].
+                1. Let |origin| be the [=serialization of an origin|serialization=] of |sourceSettings|'s [=environment settings object/origin=].
                 1. Let |source| be the result of [=getting the service worker object=] that represents |contextObject|'s [=relevant global object=]'s [=ServiceWorkerGlobalScope/service worker=] in |targetClient|.
                 1. Let |deserializeRecord| be <a abstract-op>StructuredDeserializeWithTransfer</a>(|serializeWithTransferResult|, |destination|'s [=relevant Realm=]).
 

docs/v1/index.bs

@@ -387,7 +387,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
                         <dt>Otherwise</dt>
                         <dd>a new {{Client}} object that represents |incumbentGlobal|'s associated worker
                     </dd>
-                1. Let |origin| be the [=Unicode serialization of an origin|Unicode serialization=] of |incumbentSettings|'s [=environment settings object/origin=].
+                1. Let |origin| be the [=serialization of an origin|serialization=] of |incumbentSettings|'s [=environment settings object/origin=].
                 1. Let |destination| be the {{ServiceWorkerGlobalScope}} object associated with |serviceWorker|.
                 1.  Let |deserializeRecord| be <a abstract-op>StructuredDeserializeWithTransfer</a>(|serializeWithTransferResult|, |destination|'s [=global object/Realm=]).
 
@@ -1018,7 +1018,7 @@ spec: webappsec-referrer-policy; urlPrefix: https://w3c.github.io/webappsec-refe
             1. If |targetClient| is null, return.
             1. Let |destination| be the {{ServiceWorkerContainer}} object whose associated [=ServiceWorkerContainer/service worker client=] is |targetClient|.
             1. Add a [=task=] that runs the following steps to |destination|'s [=ServiceWorkerContainer/client message queue=]:
-                1. Let |origin| be the [=Unicode serialization of an origin|Unicode serialization=] of |sourceSettings|'s [=environment settings object/origin=].
+                1. Let |origin| be the [=serialization of an origin|serialization=] of |sourceSettings|'s [=environment settings object/origin=].
                 1. Let |source| be the result of [=getting the service worker object=] that represents |contextObject|'s [=relevant global object=]'s [=ServiceWorkerGlobalScope/service worker=] in |targetClient|.
                 1. Let |deserializeRecord| be <a abstract-op>StructuredDeserializeWithTransfer</a>(|serializeWithTransferResult|, |destination|'s [=relevant Realm=]).