Set requests' render-blocking flag based on blocking="render"

See whatwg/fetch#1433 and whatwg/fetch#1432 for background.

Author: xiaochengh

source

@@ -2613,6 +2613,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
        <li><dfn data-x="concept-request-reload-navigation-flag" data-x-href="https://fetch.spec.whatwg.org/#concept-request-reload-navigation-flag">reload-navigation flag</dfn></li>
        <li><dfn data-x="concept-request-history-navigation-flag" data-x-href="https://fetch.spec.whatwg.org/#concept-request-history-navigation-flag">history-navigation flag</dfn></li>
        <li><dfn data-x="concept-request-user-activation" data-x-href="https://fetch.spec.whatwg.org/#request-user-activation">user-activation</dfn></li>
+       <li><dfn data-x="concept-request-render-blocking" data-x-href="https://fetch.spec.whatwg.org/#request-render-blocking">render-blocking</dfn></li>
        <li><dfn data-x-href="https://fetch.spec.whatwg.org/#concept-request-add-range-header">add a range header</dfn></li>
       </ul>
      </li>
@@ -16297,6 +16298,13 @@ console.log(style.disabled); // false</code></pre>
   complete, or, if the style sheet has no <span>critical subresources</span>, once the style sheet
   has been parsed and processed, the user agent must run these steps:</p>
 
+  <p class="XXX">Fetching the <span>critical subresources</span> is not well-defined; probably <a
+  href="https://github.com/whatwg/html/issues/968">issue #968</a> is the best resolution for that.
+  In the meantime, any <span data-x="critical subresources">critical subresource</span> <span
+  data-x="concept-request">request</span> should have its <span
+  data-x="concept-request-render-blocking">render-blocking</span> set to whether or not the
+  <code>style</code> element is currently <span>render-blocking</span>.</p>
+
   <ol>
    <li><p>Let <var>element</var> be the <code>style</code> element associated with the style sheet
    in question.</p></li>
@@ -26742,8 +26750,8 @@ document.body.appendChild(wbr);</code></pre>
   supported style sheet type, the user agent must instead assume it to be <code>text/css</code>.</p>
 
   <p>The <span>linked resource fetch setup steps</span> for this type of linked resource, given a
-  <code>link</code> element <var>el</var> (ignoring the <span
-  data-x="concept-request">request</span>) are:</p>
+  <code>link</code> element <var>el</var> and <span data-x="concept-request">request</span>
+  <var>request</var>, are:</p>
 
   <ol>
    <li><p>If <var>el</var>'s <code data-x="attr-link-disabled">disabled</code> attribute is set,
@@ -26758,13 +26766,19 @@ document.body.appendChild(wbr);</code></pre>
    <span>potentially render-blocking</span>, then <span>block rendering</span> on
    <var>el</var>.</p></li>
 
+   <li><p>If <var>el</var> is currently <span>render-blocking</span>, then set <var>request</var>'s
+   <span data-x="concept-request-render-blocking">render-blocking</span> to true.</p></li>
+
    <li><p>Return true.</p></li>
   </ol>
 
-  <p class="XXX">See <a href="https://github.com/whatwg/html/issues/968">issue #968</a> for plans to
-  use the CSSOM <a href="https://drafts.csswg.org/cssom/#fetching-css-style-sheets">fetch a CSS
+  <p class="XXX">See <a href="https://github.com/whatwg/html/issues/968">issue #968</a> for plans
+  to use the CSSOM <a href="https://drafts.csswg.org/cssom/#fetching-css-style-sheets">fetch a CSS
   style sheet</a> algorithm instead of the <span>default fetch and process the linked
-  resource</span> algorithm.</p>
+  resource</span> algorithm. In the meantime, any <span data-x="critical subresources">critical
+  subresource</span> <span data-x="concept-request">request</span> should have its <span
+  data-x="concept-request-render-blocking">render-blocking</span> set to whether or not the
+  <code>link</code> element is currently <span>render-blocking</span>.</p>
 
   <p>To <span data-x="process the linked resource">process this type of linked resource</span>
   given a <code>link</code> element <var>el</var>, boolean <var>success</var>, and <span
@@ -60645,6 +60659,10 @@ o............A....e
      <li><p>Set <var>el</var>'s <span data-x="concept-script-delay-load">delaying the load
      event</span> to true.</p></li>
 
+     <li><p>If <var>el</var> is currently <span>render-blocking</span>, then set
+     <var>options</var>'s <span data-x="concept-script-fetch-options-render-blocking">
+     render-blocking</span> to true.</p></li>
+
      <li>
       <p>Switch on <var>el</var>'s <span data-x="concept-script-type">type</span>:</p>
 
@@ -93243,6 +93261,12 @@ document.querySelector("button").addEventListener("click", bound);
 
    <dd><p>The <span data-x="concept-request-referrer-policy">referrer policy</span> used for the
    initial fetch and for fetching any imported modules</p></dd>
+
+   <dt><dfn data-x="concept-script-fetch-options-render-blocking">render-blocking</dfn></dt>
+
+   <dd><p>The boolean value of <span data-x="concept-request-render-blocking">render-blocking</span>
+   used for the initial fetch and for fetching any imported modules. Unless otherwise stated, its
+   value is false.</p></dd>
   </dl>
 
   <p class="note">Recall that via the <code>import()</code> feature, <span data-x="classic
@@ -93269,9 +93293,11 @@ document.querySelector("button").addEventListener("click", bound);
    data-x="concept-request-integrity-metadata">integrity metadata</span> to <var>options</var>'s
    <span data-x="concept-script-fetch-options-integrity">integrity metadata</span>, its <span
    data-x="concept-request-parser-metadata">parser metadata</span> to <var>options</var>'s <span
-   data-x="concept-script-fetch-options-parser">parser metadata</span>, and its <span
+   data-x="concept-script-fetch-options-parser">parser metadata</span>, its <span
    data-x="concept-request-referrer-policy">referrer policy</span> to <var>options</var>'s <span
-   data-x="concept-script-fetch-options-referrer-policy">referrer policy</span>.</p></dd>
+   data-x="concept-script-fetch-options-referrer-policy">referrer policy</span>, and its
+   <span data-x="concept-request-render-blocking">render-blocking</span> to <var>options</var>'s
+   <span data-x="concept-script-fetch-options-render-blocking">render-blocking</span>.</p></dd>
 
    <dt><dfn>set up the module script request</dfn></dt>
    <dd><p>Set <var>request</var>'s <span data-x="concept-request-nonce-metadata">cryptographic nonce
@@ -93282,9 +93308,11 @@ document.querySelector("button").addEventListener("click", bound);
    data-x="concept-request-parser-metadata">parser metadata</span> to <var>options</var>'s <span
    data-x="concept-script-fetch-options-parser">parser metadata</span>, its <span
    data-x="concept-request-credentials-mode">credentials mode</span> to <var>options</var>'s <span
-   data-x="concept-script-fetch-options-credentials">credentials mode</span>, and its <span
+   data-x="concept-script-fetch-options-credentials">credentials mode</span>, its <span
    data-x="concept-request-referrer-policy">referrer policy</span> to <var>options</var>'s <span
-   data-x="concept-script-fetch-options-referrer-policy">referrer policy</span>.</p></dd>
+   data-x="concept-script-fetch-options-referrer-policy">referrer policy</span>, and its
+   <span data-x="concept-request-render-blocking">render-blocking</span> to <var>options</var>'s
+   <span data-x="concept-script-fetch-options-render-blocking">render-blocking</span>.</p></dd>
   </dl>
 
   <p>For any given <span>script fetch options</span> <var>options</var>, the <dfn>descendant script