Make it optional to show UI for <a ping>

Fixes #11309.

Author: zcorpan

source

@@ -2243,7 +2243,7 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li><dfn data-x-href="https://infra.spec.whatwg.org/#implementation-defined">implementation-defined</dfn></li>
      <li><dfn data-x-href="https://infra.spec.whatwg.org/#willful-violation">willful violation</dfn></li>
      <li id="fingerprint"><span id="fingerprinting-vector"></span>
-     <!-- INSERT TRACKING -->
+     <!--INSERT TRACKING-->
      <dfn data-x-href="https://infra.spec.whatwg.org/#tracking-vector">tracking vector</dfn></li>
      <li><dfn data-x-href="https://infra.spec.whatwg.org/#code-point">code point</dfn> and its synonym
          <dfn data-x-href="https://infra.spec.whatwg.org/#code-point">character</dfn></li>
@@ -26038,17 +26038,19 @@ document.body.appendChild(wbr);</code></pre>
   <p>User agents must ignore any entity bodies returned in the responses. User agents may close the
   connection prematurely once they start receiving a response body.</p>
 
-  <p>When the <code data-x="attr-hyperlink-ping">ping</code> attribute is present, user agents
-  should clearly indicate to the user that following the hyperlink will also cause secondary
-  requests to be sent in the background, possibly including listing the actual target URLs.</p>
+  <p id="fingerprint-ping">
+  <!--INSERT TRACKING-->
+  An <code>a</code> or <code>area</code> element that creates a <span>hyperlink</span> and has
+  the <code data-x="attr-hyperlink-ping">ping</code> attribute is present, user agents may indicate
+  to the user that following the hyperlink will also cause secondary requests to be sent in the
+  background, possibly including listing the actual target URLs.</p>
 
   <p class="example">For example, a visual user agent could include the hostnames of the target ping
   URLs along with the hyperlink's actual URL in a status bar or tooltip.</p>
 
   </div>
 
   <div class="note">
-
    <p>The <code data-x="attr-hyperlink-ping">ping</code> attribute is redundant with pre-existing
    technologies like HTTP redirects and JavaScript in allowing web pages to track which off-site
    links are most popular or allowing advertisers to track click-through rates.</p>
@@ -26061,17 +26063,9 @@ document.body.appendChild(wbr);</code></pre>
 
     <li>It allows the UA to inform the user about the out-of-band notifications.</li>
 
-    <li>It allows the user to disable the notifications without losing the underlying link
-    functionality.</li>
-
     <li>It allows the UA to optimize the use of available network bandwidth so that the target page
     loads faster.</li>
    </ul>
-
-   <p>Thus, while it is possible to track users without this feature, authors are encouraged to use
-   the <code data-x="attr-hyperlink-ping">ping</code> attribute so that the user agent can make the
-   user experience more transparent.</p>
-
   </div>
 
   <!-- resolving ping urls happens at audit time, so base URL changes affect the values of ping
@@ -110651,7 +110645,7 @@ document.querySelector("button").addEventListener("click", bound);
 
    <li>
     <p>
-     <!-- INSERT TRACKING-->
+     <!--INSERT TRACKING-->
      Set <var>attributes</var>[<code data-x="dom-ErrorEvent-message">message</code>],
      <var>attributes</var>[<code data-x="dom-ErrorEvent-filename">filename</code>],
      <var>attributes</var>[<code data-x="dom-ErrorEvent-lineno">lineno</code>], and
@@ -118546,8 +118540,9 @@ interface <dfn interface>MimeType</dfn> {
   legacy code relies on. This section specifies both the simple modern variant and the complicated
   historical one.</p>
 
-  <!-- INSERT TRACKING -->
-  <p>Each user agent has a <dfn>PDF viewer supported</dfn> boolean, whose value is
+  <p id="fingerprint-pdfViewerEnabled">
+  <!--INSERT TRACKING-->
+  Each user agent has a <dfn>PDF viewer supported</dfn> boolean, whose value is
   <span>implementation-defined</span> (and might vary according to user preferences).</p>
 
   <p class="note">This value also impacts the <span data-x="navigate">navigation</span> processing
@@ -120778,7 +120773,7 @@ data:&nbsp;test
   designed to not enable cross-site scripting attacks.</p>
 
   <p class="note" id="fingerprint-postMessage">
-  <!-- INSERT TRACKING -->
+  <!--INSERT TRACKING-->
   The <code data-x="dom-window-postMessage">postMessage()</code> API can be used as a <span>tracking
   vector</span>.</p>