CREDENTIAL: Add a warning to the demo page.

Author: mikewest

demos/credential-management/script.js

@@ -10,6 +10,11 @@ if (navigator.credentials) {
     password: true,
     suppressUI: true
   }).then(processResponse);
+} else {
+  var section = document.createElement('section');
+  section.innerHTML = "<p><code>navigator.credentials</code> is not available! Have you enabled the feature in your browser? (Visit <code>chrome://flags/#enable-credential-manager-api</code> in Chrome, for example.)</p>";
+  section.classList.toggle('warning');
+  document.body.appendChild(section);
 }
 
 function toggleState() {

demos/credential-management/style.css

@@ -1,6 +1,6 @@
 body {
   margin: 0 auto;
-  width: 500px;  
+  width: 500px;
 }
 header {
   background: #EEE;
@@ -27,7 +27,7 @@ section.signedout, section.signedin {
   display: none;
 }
 
-.signedout section.signedout {
+.signedout section.signedout, .warning {
   border: 1px solid #999;
   background: #FF6666;
   margin: 0.25em 0;