Change <link>'s usecache to updateviacache

This is part of w3c/ServiceWorker#1104.

source

@@ -3791,6 +3791,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#serviceworkercontainer"><code>ServiceWorkerContainer</code></dfn> interface</li>
      <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#serviceworkerglobalscope"><code>ServiceWorkerGlobalScope</code></dfn> interface</li>
      <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#dfn-use-cache">use cache</dfn></li>
+     <li><dfn data-x-href="https://w3c.github.io/ServiceWorker/#dfn-update-via-cache">update via cache mode</dfn></li>
     </ul>
 
    </dd>
@@ -12909,7 +12910,7 @@ interface <dfn>HTMLBaseElement</dfn> : <span>HTMLElement</span> {
    <dd><code data-x="attr-link-sizes">sizes</code></dd>
    <dd><code data-x="attr-link-as">as</code></dd>
    <dd><code data-x="attr-link-scope">scope</code></dd>
-   <dd><code data-x="attr-link-usecache">usecache</code></dd>
+   <dd><code data-x="attr-link-updateviacache">updateviacache</code></dd>
    <dd><code data-x="attr-link-workertype">workertype</code></dd>
    <dd><code data-x="attr-link-color">color</code></dd>
    <dd>Also, the <code data-x="attr-link-title">title</code> attribute <span data-x="attr-link-title">has special semantics</span> on this element.</dd>
@@ -12931,7 +12932,7 @@ interface <dfn>HTMLLinkElement</dfn> : <span>HTMLElement</span> {
   [<span>CEReactions</span>] attribute DOMString <span data-x="dom-link-referrerPolicy">referrerPolicy</span>;
   [<span>CEReactions</span>] attribute USVString <span data-x="dom-link-scope">scope</span>;
   [<span>CEReactions</span>] attribute <span>WorkerType</span> <span data-x="dom-link-workertype">workerType</span>;
-  [<span>CEReactions</span>] attribute boolean <span data-x="dom-link-useCache">useCache</span>;
+  [<span>CEReactions</span>] attribute DOMString <span data-x="dom-link-updateviacache">updateViaCache</span>;
 };
 <span>HTMLLinkElement</span> implements <span>LinkStyle</span>;</pre>
    </dd>
@@ -13138,11 +13139,13 @@ interface <dfn>HTMLLinkElement</dfn> : <span>HTMLElement</span> {
   specified on <code>link</code> elements that do not have a <code data-x="attr-link-rel">rel</code>
   attribute that contains the <code data-x="rel-serviceworker">serviceworker</code> keyword.</p>
 
-  <p>The <dfn><code data-x="attr-link-usecache">usecache</code></dfn> attribute is a <span>boolean
-  attribute</span> which sets <span>use cache</span> to true for a <span>service worker
-  registration</span>. The attribute must not be specified on <code>link</code> elements that do not
-  have a <code data-x="attr-link-rel">rel</code> attribute that contains the <code
-  data-x="rel-serviceworker">serviceworker</code> keyword.</p>
+  <p>The <dfn><code data-x="attr-link-updateviacache">updateviacache</code></dfn> attribute
+  specifies the <span>update via cache mode</span> for a <span>service worker registration</span>.
+  It is an <span>enumerated attribute</span>. Each <span>update via cache mode</span> is a keyword
+  for this attribute, mapping to a state of the same name. The <span>missing value default</span> is
+  the <i>imports</i> state. The attribute must not be specified on <code>link</code> elements that
+  do not have a <code data-x="attr-link-rel">rel</code> attribute that contains the
+  <code data-x="rel-serviceworker">serviceworker</code> keyword.</p>
 
   <p>The <dfn><code data-x="attr-link-workertype">workertype</code></dfn> attribute is an
   <span>enumerated attribute</span> that specifies the <span>service worker type</span> for a
@@ -13202,8 +13205,9 @@ interface <dfn>HTMLLinkElement</dfn> : <span>HTMLElement</span> {
   <p>The <dfn><code data-x="dom-link-rellist">relList</code></dfn> IDL attribute must <span
   data-x="reflect">reflect</span> the <code data-x="attr-link-rel">rel</code> content attribute.</p>
 
-  <p>The <dfn><code data-x="dom-link-useCache">useCache</code></dfn> IDL attribute must
-  <span>reflect</span> the <code data-x="attr-link-usecache">usecache</code> content attribute.</p>
+  <p>The <dfn><code data-x="dom-link-updateViaCache">updateViaCache</code></dfn> IDL attribute must
+  <span>reflect</span> the <code data-x="attr-link-updateviacache">updateviacache</code> content
+  attribute, <span>limited to only known values</span>.</p>
 
   <p>The <dfn><code data-x="dom-link-workerType">workerType</code></dfn> IDL attribute must
   <span>reflect</span> the <code data-x="attr-link-workertype">workertype</code> content
@@ -24072,13 +24076,14 @@ interface <dfn>HTMLHyperlinkElementUtils</dfn> {
   <code>link</code> elements. This keyword creates an <span data-x="external resource link">external
   resource link</span> that is used to declare a <span>service worker registration</span> and its
   <span>script url</span>, <span>scope url</span>, <span data-x="service worker type">type</span>,
-  and <span>use cache</span> setting.</p>
+  and <span>update via cache mode</span>.</p>
 
   <p><span w-nodev>User agents must implement the processing model for <code>link</code>-element
   <span data-x="serviceworker link">serviceworker links</span> described in <cite>Service
   Workers</cite>, using the <code data-x="attr-link-href">href</code>, <code
   data-x="attr-link-scope">scope</code>, <code data-x="attr-link-workertype">workertype</code>, and
-  <code data-x="attr-link-usecache">usecache</code> attributes.</span> <ref spec="SW"></p>
+  <code data-x="attr-link-updateviacache">updateviacache</code> attributes.</span>
+  <ref spec="SW"></p>
 
 <!--ADD-TOPIC:CSS-->
   <h5>Link type "<dfn><code data-x="rel-stylesheet">stylesheet</code></dfn>"</h5>
@@ -118512,10 +118517,10 @@ interface <dfn>External</dfn> {
      <td> Whether the <code data-x="attr-object-type">type</code> attribute and the <span>Content-Type</span> value need to match for the resource to be used
      <td> <span>Boolean attribute</span>
     <tr>
-     <th> <code data-x="">usecache</code>
-     <td> <code data-x="attr-link-usecache">link</code>
-     <td> Whether to set <span>use cache</span> to true for a <span>service worker registration</span> (for <code data-x="attr-link-rel">rel</code>="<code data-x="rel-serviceworker">serviceworker</code>")
-     <td> <span>Boolean attribute</span>
+     <th> <code data-x="">updateviacache</code>
+     <td> <code data-x="attr-link-updateviacache">link</code>
+     <td> <span>Update via cache mode</span> for a <span>service worker registration</span> (for <code data-x="attr-link-rel">rel</code>="<code data-x="rel-serviceworker">serviceworker</code>")
+     <td> <span>Update via cache mode</span>
     <tr>
      <th> <code data-x="">usemap</code>
      <td> <code data-x="attr-hyperlink-usemap">img</code>;