preferences.js

function showEnableExtensionMessage(settingName) {
  let elements = getControllingExtensionEls(settingName);
  if (elements.button
      && extensionControlledIds[settingName]
      && !document.hidden) {
    elements.button.hidden = true;
    elements.section.classList.add("extension-controlled-disabled");
    let icon = url => `<image src="${url}" class="extension-controlled-icon"/>`;
    let addonIcon = icon("chrome://mozapps/skin/extensions/extensionGeneric-16.svg");
    let toolbarIcon = icon("chrome://browser/skin/menu.svg");
    let message = document
      .getElementById("bundlePreferences")
      .getFormattedString("extensionControlled.enable", [addonIcon, toolbarIcon]);
    // eslint-disable-next-line no-unsanitized/property
    elements.description.innerHTML = message;
    let dismissButton = document.createElement("image");
    dismissButton.setAttribute("class", "extension-controlled-icon close-icon");
    dismissButton.addEventListener("click", function dismissHandler() {
      hideControllingExtension(settingName);
      dismissButton.removeEventListener("click", dismissHandler);
    });
    elements.description.appendChild(dismissButton);
  } else {
    elements.section.hidden = true;
  }
}