Remove ServiceWorkerGlobalScope.close()

Remove ServiceWorkerGlobalScope.close() by moving worker's close() to dedicated
worker and shared worker in HTML: whatwg/html@4081f12

Fixes #865

spec/service_worker/index.bs

@@ -1066,17 +1066,13 @@ spec: webidl; urlPrefix: https://heycam.github.io/webidl/
 
         // event
         attribute EventHandler onmessage; // event.source of the message events is Client object
-
-        // close() method inherited from WorkerGlobalScope <a href="#service-worker-global-scope-close-method"><em class="rfc2119" title="SHOULD NOT">should not</em> be accessible</a>.
       };
     </pre>
 
     <p>A <code><dfn interface id="service-worker-global-scope-interface">ServiceWorkerGlobalScope</a></code> object represents the global execution context of a <a href="#dfn-service-worker">service worker</a>. A {{ServiceWorkerGlobalScope}} object has an associated <dfn id="dfn-service-worker-global-scope-service-worker">service worker</dfn> (a <a href="#dfn-service-worker">service worker</a>).</p>
 
     <p class="note">{{ServiceWorkerGlobalScope}} object provides generic, event-driven, time-limited script execution contexts that run at an origin. Once successfully <a href="#navigator-service-worker-register">registered</a>, a <a href="#dfn-service-worker">service worker</a> is started, kept alive and killed by their relationship to events, not <a href="#dfn-service-worker-client">service worker clients</a>. Any type of synchronous requests must not be initiated inside of a <a href="#dfn-service-worker">service worker</a>.</p>
 
-    <p id="service-worker-global-scope-close-method" class="note">The {{WorkerGlobalScope/close()}} method inherited from {{WorkerGlobalScope}}, when called on the <a>context object</a>, should <a>throw</a> an "{{InvalidAccessError}}" exception.</p>
-
     <section>
       <h4 id="service-worker-global-scope-clients">{{ServiceWorkerGlobalScope/clients}}</h4>