Get rid of flicker

ext/bg/js/templates.js

@@ -1,11 +1,7 @@
 (function() {
   var template = Handlebars.template, templates = Handlebars.templates = Handlebars.templates || {};
 templates['footer.html'] = template({"compiler":[7,">= 4.0.0"],"main":function(container,depth0,helpers,partials,data) {
-    var helper;
-
-  return "    <script src=\""
-    + container.escapeExpression(((helper = (helper = helpers.root || (depth0 != null ? depth0.root : depth0)) != null ? helper : helpers.helperMissing),(typeof helper === "function" ? helper.call(depth0 != null ? depth0 : {},{"name":"root","hash":{},"data":data}) : helper)))
-    + "/js/popup.js\"></script>\n    </body>\n</html>\n";
+    return "    </body>\n</html>\n";
 },"useData":true});
 templates['header.html'] = template({"compiler":[7,">= 4.0.0"],"main":function(container,depth0,helpers,partials,data) {
     var helper;

ext/fg/js/popup.js

@@ -63,9 +63,14 @@ class Popup {
     }
 
     setContent(content) {
-        if (this.popup !== null) {
-            this.popup.setAttribute('srcdoc', content);
+        if (this.popup === null) {
+            return;
         }
+
+        const doc = this.popup.contentDocument;
+        doc.open();
+        doc.write(content);
+        doc.close();
     }
 
     inject() {

ext/manifest.json

@@ -20,7 +20,7 @@
     "background":               {"page": "bg/background.html"},
     "options_page":             "bg/options.html",
     "permissions":              ["storage"],
-    "web_accessible_resources": ["fg/css/popup.css", "fg/js/popup.js"],
+    "web_accessible_resources": ["fg/css/popup.css"],
 
     "content_scripts": [{
         "matches": ["*://*/*"],

util/tmpl/footer.html

@@ -1,3 +1,2 @@
-    <script src="{{root}}/js/popup.js"></script>
     </body>
 </html>