Snapshot policy container on navigation requests

source

@@ -2538,6 +2538,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
        <li><dfn data-x="concept-request-cache-mode" data-x-href="https://fetch.spec.whatwg.org/#concept-request-cache-mode">cache mode</dfn></li>
        <li><dfn data-x="concept-request-redirect-count" data-x-href="https://fetch.spec.whatwg.org/#concept-request-redirect-count">redirect count</dfn></li>
        <li><dfn data-x="concept-request-redirect-mode" data-x-href="https://fetch.spec.whatwg.org/#concept-request-redirect-mode">redirect mode</dfn></li>
+       <li><dfn data-x="concept-request-policy-container" data-x-href="https://fetch.spec.whatwg.org/#concept-request-policy-container">policy container</dfn></li>
        <li><dfn data-x="concept-request-referrer-policy" data-x-href="https://fetch.spec.whatwg.org/#concept-request-referrer-policy">referrer policy</dfn></li>
        <li><dfn data-x="concept-request-nonce-metadata" data-x-href="https://fetch.spec.whatwg.org/#concept-request-nonce-metadata">cryptographic nonce metadata</dfn></li>
        <li><dfn data-x="concept-request-integrity-metadata" data-x-href="https://fetch.spec.whatwg.org/#concept-request-integrity-metadata">integrity metadata</dfn></li>
@@ -85500,6 +85501,10 @@ interface <dfn>Location</dfn> { // but see also <a href="#the-location-interface
    document</span>'s <span data-x="concept-document-policy-container">policy
    container</span>.</p></li>
 
+   <li><p>If <var>resource</var> is a <span data-x="concept-request">request</span>, then set
+   <var>resource</var>'s <span data-x="concept-request-policy-container">policy container</span> to
+   <var>initiatorPolicyContainer</var>.</p></li>
+
    <li><p>Cancel any preexisting but not yet <span data-x="concept-navigate-mature">mature</span>
    attempt to navigate <var>browsingContext</var>, including canceling any instances of the <span
    data-x="concept-fetch">fetch</span> algorithm started by those attempts. If one of those attempts