clarify: set workerStart to zero

index.html

@@ -696,7 +696,7 @@ <h3>Processing Model</h3>
       <li>Record the initiator of the resource in <a href="#widl-PerformanceResourceTiming-initiatorType">initiatorType</a>.
       </li>
 
-      <li>Record the <a href="http://www.w3.org/TR/html5/infrastructure.html#resolve-a-url">resolved URL</a> of the requested resource in <a href="#widl-PerformanceResourceTiming-name">name</a>. If there is an <a href="http://www.w3.org/TR/service-workers/#dfn-containing-service-worker-registration">active worker</a> ([[!SERVICE-WORKERS]]) matching the current browsing or worker context's, immediately before the user agent <a href="http://www.w3.org/TR/service-workers/#service-worker-concept">runs the worker</a> record the time as <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a>, or if the worker is available, immediately before the <a href="http://www.w3.org/TR/service-workers/#on-fetch-request-algorithm">event named `fetch` is fired</a> at the active worker record the time as <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a>. Otherwise, if <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a> attribute is supported but there is no matching <a href="http://www.w3.org/TR/service-workers/#dfn-service-worker-registration">service worker registration</a>, set the value to zero.</li>
+      <li>Record the <a href="http://www.w3.org/TR/html5/infrastructure.html#resolve-a-url">resolved URL</a> of the requested resource in <a href="#widl-PerformanceResourceTiming-name">name</a>. If there is an <a href="http://www.w3.org/TR/service-workers/#dfn-containing-service-worker-registration">active worker</a> ([[!SERVICE-WORKERS]]) matching the current browsing or worker context's, immediately before the user agent <a href="http://www.w3.org/TR/service-workers/#service-worker-concept">runs the worker</a> record the time as <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a>, or if the worker is available, immediately before the <a href="http://www.w3.org/TR/service-workers/#on-fetch-request-algorithm">event named `fetch` is fired</a> at the active worker record the time as <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a>. Otherwise, if <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a> attribute is supported but there is no matching <a href="http://www.w3.org/TR/service-workers/#dfn-service-worker-registration">service worker registration</a>, set <a href="#widl-PerformanceResourceTiming-workerStart">workerStart</a> value to zero.</li>
 
       <li id="step-fetch-start">Immediately before a user agent starts the <a href="http://www.w3.org/TR/html5/infrastructure.html#fetch" title='fetch'>fetching process</a>, record the current time as <a href="#widl-PerformanceResourceTiming-fetchStart">fetchStart</a>. Let <a href="#widl-PerformanceResourceTiming-domainLookupStart">domainLookupStart</a>, <a href="#widl-PerformanceResourceTiming-domainLookupEnd">domainLookupEnd</a>, <a href="#widl-PerformanceResourceTiming-connectStart">connectStart</a> and <a href="#widl-PerformanceResourceTiming-connectEnd">connectEnd</a> be the same value as <a href="#widl-PerformanceResourceTiming-fetchStart">fetchStart</a>.</li>