WebDriver BiDi: emulate network offline

Address WebDriver BiDi integration by using Fetch's new "is offline" primitive.

Author: sadym-chromium

source

@@ -2675,6 +2675,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://fetch.spec.whatwg.org/#credentials">credentials</dfn></li>
      <li><dfn data-x-href="https://fetch.spec.whatwg.org/#reserve-deferred-fetch-quota">reserve deferred fetch quota</dfn></li>
      <li><dfn data-x-href="https://fetch.spec.whatwg.org/#reserve-deferred-fetch-quota">potentially free deferred fetch quota</dfn></li>
+     <li><dfn data-x-href="https://fetch.spec.whatwg.org/#is-offline">is offline</dfn></li>
      <li>
       <dfn data-x="concept-response"
       data-x-href="https://fetch.spec.whatwg.org/#concept-response">response</dfn> and its
@@ -125571,9 +125572,9 @@ interface <dfn interface>Navigator</dfn> {
 
   <div algorithm>
   <p>The <dfn attribute for="NavigatorOnLine"><code
-  data-x="dom-navigator-onLine">onLine</code></dfn> attribute must return false if the user agent
-  will not contact the network when the user follows links or when a script requests a remote page
-  (or knows that such an attempt would fail), and must return true otherwise.</p>
+  data-x="dom-navigator-onLine">onLine</code></dfn> getter steps are to return true if
+  <span>this</span>'s <span>relevant settings object</span> <span>is offline</span> is false;
+  otherwise false.</p>
   </div>
 
   <div algorithm>