[Demo] Issue 6047 - Missing background on uninstallation page

static/js/uninstalled.js

+  (function()
+  {
+    var adblockersList = null;
+    function toggleView(element)
+    {
+      var targetId = element.getAttribute("data-toggle-view");
+      if (targetId)
+        document.getElementById(targetId).classList.toggle("hidden");
+    }
+
+    function checkSelectedAdblocker()
+    {
+      var selectedOption = adblockersList[adblockersList.selectedIndex];
+      var element = selectedOption.getAttribute("data-show-element");
+      if (element)
+        document.getElementById(element).classList.remove("hidden");
+      else
+      {
+        element = selectedOption.getAttribute("data-hide-element");
+        document.getElementById(element).classList.add("hidden");
+      }
+    }
+
+    function init()
+    {
+      var form = document.getElementById("reasons-form");
+
+      // Create hidden input for GET parameters
+      window.location.search.substr(1).split("&").forEach(function(param)
+      {
+        if (!/.=./.test(param))
+          return;
+
+        var paramSplit = param.split("=");
+        var input = document.createElement("input");
+        input.setAttribute("type", "hidden");
+        input.setAttribute("name", decodeURIComponent(paramSplit[0]));
+        input.setAttribute("value", decodeURIComponent(paramSplit[1]));
+        form.appendChild(input);
+      });
+
+      // Randomly add reasons
+      var reasonsContainer = document.getElementById("reasons");
+      var reasons = document.querySelectorAll("#reasons > li");
+      reasons = Array.prototype.slice.call(reasons);
+      reasonsContainer.innerHTML = "";
+      while (reasons.length)
+      {
+        var randomIndex = Math.floor(Math.random() * (reasons.length -1));
+        var reasonElement = reasons.splice(randomIndex, 1)[0];
+        reasonsContainer.appendChild(reasonElement);
+        var checkbox = reasonElement.querySelector("input[type=checkbox]");
+        if (checkbox.checked)
+          toggleView(checkbox);
+
+        checkbox.addEventListener("change", function(event)
+        {
+          toggleView(event.target);
+        }, false);
+      }
+
+      adblockersList = document.querySelector("#adblockers select");
+      adblockersList.addEventListener("change", function()
+      {
+        checkSelectedAdblocker();
+      }, false);
+      checkSelectedAdblocker();
+
+      var reasonOtherInput = document.getElementById("reason-other-input");
+      var maxLength = reasonOtherInput.getAttribute("maxlength");
+      var charCounter = document.getElementById("characters-countdown");
+      charCounter.textContent = maxLength;
+      reasonOtherInput.addEventListener("keyup", function()
+      {
+        charCounter.textContent = maxLength - reasonOtherInput.value.length;
+      }, false);
+
+      var submitButton = document.getElementById("reason-submit");
+      submitButton.addEventListener("click", function(event)
+      {
+        if (!document.querySelector("ul input:checked"))
+        {
+          event.preventDefault();
+          form.setAttribute("class", "error");
+        }
+        else
+        {
+          form.submit();
+        }
+      }, false);
+    }
+    document.addEventListener("DOMContentLoaded", init, false);
+  })();