Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

164 files changed, 14951 insertions, 0 deletions

diff --git a/browser/extensions/webcompat/about-compat/AboutCompat.jsm b/browser/extensions/webcompat/about-compat/AboutCompat.jsm
new file mode 100644
index 0000000000..7c844726f8
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/AboutCompat.jsm
@@ -0,0 +1,42 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+var EXPORTED_SYMBOLS = ["AboutCompat"];
+
+const Services =
+  globalThis.Services ||
+  ChromeUtils.import("resource://gre/modules/Services.jsm").Services;
+
+const addonID = "webcompat@mozilla.org";
+const addonPageRelativeURL = "/about-compat/aboutCompat.html";
+
+function AboutCompat() {
+  this.chromeURL =
+    WebExtensionPolicy.getByID(addonID).getURL(addonPageRelativeURL);
+}
+AboutCompat.prototype = {
+  QueryInterface: ChromeUtils.generateQI(["nsIAboutModule"]),
+  getURIFlags() {
+    return (
+      Ci.nsIAboutModule.URI_MUST_LOAD_IN_EXTENSION_PROCESS |
+      Ci.nsIAboutModule.IS_SECURE_CHROME_UI
+    );
+  },
+
+  newChannel(aURI, aLoadInfo) {
+    const uri = Services.io.newURI(this.chromeURL);
+    const channel = Services.io.newChannelFromURIWithLoadInfo(uri, aLoadInfo);
+    channel.originalURI = aURI;
+
+    channel.owner = (
+      Services.scriptSecurityManager.createContentPrincipal ||
+      // Handles fallback to earlier versions.
+      // eslint-disable-next-line mozilla/valid-services-property
+      Services.scriptSecurityManager.createCodebasePrincipal
+    )(uri, aLoadInfo.originAttributes);
+    return channel;
+  },
+};
diff --git a/browser/extensions/webcompat/about-compat/aboutCompat.css b/browser/extensions/webcompat/about-compat/aboutCompat.css
new file mode 100644
index 0000000000..b51db7f9f5
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/aboutCompat.css
@@ -0,0 +1,187 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+@media (any-pointer: fine) {
+  :root {
+    font-family: sans-serif;
+    margin: 40px auto;
+    min-width: 30em;
+    max-width: 60em;
+  }
+
+  table {
+    width: 100%;
+    padding-bottom: 2em;
+    border-spacing: 0;
+  }
+
+  td {
+    border-bottom: 1px solid var(--in-content-border-color);
+  }
+
+  td:last-child > button {
+    float: inline-end;
+  }
+}
+
+/* Mobile UI where common.css is not loaded */
+
+@media (any-pointer: coarse), (any-pointer: none) {
+  * {
+    margin: 0;
+    padding: 0;
+  }
+
+  :root {
+    --background-color: #fff;
+    --text-color: #0c0c0d;
+    --border-color: #e1e1e2;
+    --button-background-color: #f5f5f5;
+    --selected-tab-text-color: #0061e0;
+  }
+
+  @media (prefers-color-scheme: dark) {
+    :root {
+      --background-color: #292833;
+      --text-color: #f9f9fa;
+      --border-color: rgba(255, 255, 255, 0.15);
+      --button-background-color: rgba(0, 0, 0, 0.15);
+      --selected-tab-text-color: #00ddff;
+    }
+  }
+
+  body {
+    background-color: var(--background-color);
+    color: var(--text-color);
+    font: message-box;
+    font-size: 14px;
+    -moz-text-size-adjust: none;
+    display: grid;
+    grid-template-areas: "a b c" "d d d";
+    grid-template-columns: 1fr 1fr 1fr;
+    grid-template-rows: fit-content(100%) 1fr;
+  }
+
+  .tab[data-l10n-id="label-overrides"] {
+    grid-area: a;
+  }
+
+  .tab[data-l10n-id="label-interventions"] {
+    grid-area: b;
+  }
+
+  .tab[data-l10n-id="label-smartblock"] {
+    grid-area: c;
+  }
+
+  table {
+    grid-area: d;
+  }
+
+  table,
+  tr,
+  p {
+    display: block;
+  }
+
+  table {
+    border-top: 2px solid var(--border-color);
+    margin-top: -2px;
+    width: 100%;
+    z-index: 1;
+    display: none;
+  }
+
+  tr {
+    border-bottom: 1px solid var(--border-color);
+    padding: 0;
+  }
+
+  a {
+    color: inherit;
+    font-size: 94%;
+  }
+
+  .tab {
+    cursor: pointer;
+    z-index: 2;
+    display: inline-block;
+    text-align: left;
+    border-block: 2px solid transparent;
+    font-size: 1em;
+    font-weight: bold;
+    padding: 1em;
+  }
+
+  .tab.active {
+    color: var(--selected-tab-text-color);
+    border-bottom-color: currentColor;
+    margin-bottom: 0;
+    padding-bottom: calc(1em + 2px);
+  }
+
+  .tab.active + table {
+    display: block;
+  }
+
+  td {
+    grid-area: b;
+    padding-left: 1em;
+  }
+
+  td:first-child {
+    grid-area: a;
+    padding-top: 1em;
+  }
+
+  td:last-child {
+    grid-area: c;
+    padding-bottom: 1em;
+  }
+
+  tr {
+    display: grid;
+    grid-template-areas: "a c" "b c";
+    grid-template-columns: 1fr 6.5em;
+  }
+
+  td[colspan="4"] {
+    padding: 1em;
+    font-style: italic;
+    text-align: center;
+  }
+
+  td:not([colspan]):nth-child(1) {
+    font-weight: bold;
+    padding-bottom: 0.25em;
+  }
+
+  td:nth-child(2) {
+    padding-bottom: 1em;
+  }
+
+  td:nth-child(3) {
+    display: flex;
+    padding: 0;
+  }
+
+  button {
+    cursor: pointer;
+    width: 100%;
+    height: 100%;
+    background: var(--button-background-color);
+    color: inherit;
+    inset-inline-end: 0;
+    margin: 0;
+    padding: 0;
+    border: 0;
+    border-inline-start: 1px solid var(--border-color);
+    font-weight: 600;
+    appearance: none;
+  }
+
+  button::-moz-focus-inner {
+    border: 0;
+  }
+}
diff --git a/browser/extensions/webcompat/about-compat/aboutCompat.html b/browser/extensions/webcompat/about-compat/aboutCompat.html
new file mode 100644
index 0000000000..d820f20ee2
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/aboutCompat.html
@@ -0,0 +1,51 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<!DOCTYPE html>
+<html>
+  <head>
+    <base />
+
+    <!-- If you change this script tag you must update the hash in the extension's
+         `content_security_policy` 'sha256-MmZkN2QaIHhfRWPZ8TVRjijTn5Ci1iEabtTEWrt9CCo=' -->
+    <script>
+      /* globals browser */ document.head.firstElementChild.href =
+        browser.runtime.getURL("");
+    </script>
+
+    <meta charset="utf-8" />
+    <meta name="color-scheme" content="light dark" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <link rel="stylesheet" href="about-compat/aboutCompat.css" />
+    <link
+      rel="stylesheet"
+      media="screen and (pointer:fine), projection"
+      type="text/css"
+      href="chrome://global/skin/in-content/common.css"
+    />
+    <link rel="localization" href="toolkit/about/aboutCompat.ftl" />
+    <title data-l10n-id="text-title"></title>
+    <script src="about-compat/aboutCompat.js"></script>
+  </head>
+  <body>
+    <h2 class="tab active" data-l10n-id="label-overrides"></h2>
+    <table id="overrides">
+      <col />
+      <col />
+      <col />
+    </table>
+    <h2 class="tab" data-l10n-id="label-interventions"></h2>
+    <table id="interventions">
+      <col />
+      <col />
+      <col />
+    </table>
+    <h2 class="tab" data-l10n-id="label-smartblock"></h2>
+    <table id="smartblock" class="shims">
+      <col />
+      <col />
+      <col />
+    </table>
+  </body>
+</html>
diff --git a/browser/extensions/webcompat/about-compat/aboutCompat.js b/browser/extensions/webcompat/about-compat/aboutCompat.js
new file mode 100644
index 0000000000..e01b853877
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/aboutCompat.js
@@ -0,0 +1,283 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+let availablePatches;
+
+const portToAddon = (function () {
+  let port;
+
+  function connect() {
+    port = browser.runtime.connect({ name: "AboutCompatTab" });
+    port.onMessage.addListener(onMessageFromAddon);
+    port.onDisconnect.addListener(e => {
+      port = undefined;
+    });
+  }
+
+  connect();
+
+  async function send(message) {
+    if (port) {
+      return port.postMessage(message);
+    }
+    return Promise.reject("background script port disconnected");
+  }
+
+  return { send };
+})();
+
+const $ = function (sel) {
+  return document.querySelector(sel);
+};
+
+const DOMContentLoadedPromise = new Promise(resolve => {
+  document.addEventListener(
+    "DOMContentLoaded",
+    () => {
+      resolve();
+    },
+    { once: true }
+  );
+});
+
+Promise.all([
+  browser.runtime.sendMessage("getAllInterventions"),
+  DOMContentLoadedPromise,
+]).then(([info]) => {
+  document.body.addEventListener("click", async evt => {
+    const ele = evt.target;
+    if (ele.nodeName === "BUTTON") {
+      const row = ele.closest("[data-id]");
+      if (row) {
+        evt.preventDefault();
+        ele.disabled = true;
+        const id = row.getAttribute("data-id");
+        try {
+          await browser.runtime.sendMessage({ command: "toggle", id });
+        } catch (_) {
+          ele.disabled = false;
+        }
+      }
+    } else if (ele.classList.contains("tab")) {
+      document.querySelectorAll(".tab").forEach(tab => {
+        tab.classList.remove("active");
+      });
+      ele.classList.add("active");
+    }
+  });
+
+  availablePatches = info;
+  redraw();
+});
+
+function onMessageFromAddon(msg) {
+  const alsoShowHidden = location.hash === "#all";
+
+  if ("interventionsChanged" in msg) {
+    redrawTable($("#interventions"), msg.interventionsChanged, alsoShowHidden);
+  }
+
+  if ("overridesChanged" in msg) {
+    redrawTable($("#overrides"), msg.overridesChanged, alsoShowHidden);
+  }
+
+  if ("shimsChanged" in msg) {
+    updateShimTables(msg.shimsChanged, alsoShowHidden);
+  }
+
+  const id = msg.toggling || msg.toggled;
+  const button = $(`[data-id="${id}"] button`);
+  if (!button) {
+    return;
+  }
+  const active = msg.active;
+  document.l10n.setAttributes(
+    button,
+    active ? "label-disable" : "label-enable"
+  );
+  button.disabled = !!msg.toggling;
+}
+
+function redraw() {
+  if (!availablePatches) {
+    return;
+  }
+  const { overrides, interventions, shims } = availablePatches;
+  const alsoShowHidden = location.hash === "#all";
+  redrawTable($("#overrides"), overrides, alsoShowHidden);
+  redrawTable($("#interventions"), interventions, alsoShowHidden);
+  updateShimTables(shims, alsoShowHidden);
+}
+
+function clearTableAndAddMessage(table, msgId) {
+  table.querySelectorAll("tr").forEach(tr => {
+    tr.remove();
+  });
+
+  const tr = document.createElement("tr");
+  tr.className = "message";
+  tr.id = msgId;
+
+  const td = document.createElement("td");
+  td.setAttribute("colspan", "3");
+  document.l10n.setAttributes(td, msgId);
+  tr.appendChild(td);
+
+  table.appendChild(tr);
+}
+
+function hideMessagesOnTable(table) {
+  table.querySelectorAll("tr.message").forEach(tr => {
+    tr.remove();
+  });
+}
+
+function updateShimTables(shimsChanged, alsoShowHidden) {
+  const tables = document.querySelectorAll("table.shims");
+  if (!tables.length) {
+    return;
+  }
+
+  for (const { bug, disabledReason, hidden, id, name, type } of shimsChanged) {
+    // if any shim is disabled by global pref, all of them are. just show the
+    // "disabled in about:config" message on each shim table in that case.
+    if (disabledReason === "globalPref") {
+      for (const table of tables) {
+        clearTableAndAddMessage(table, "text-disabled-in-about-config");
+      }
+      return;
+    }
+
+    // otherwise, find which table the shim belongs in. if there is none,
+    // ignore the shim (we're not showing it on the UI for whatever reason).
+    const table = document.querySelector(`table.shims#${type}`);
+    if (!table) {
+      continue;
+    }
+
+    // similarly, skip shims hidden from the UI (only for testing, etc).
+    if (!alsoShowHidden && hidden) {
+      continue;
+    }
+
+    // also, hide the shim if it is disabled because it is not meant for this
+    // platform, release (etc) rather than being disabled by pref/about:compat
+    const notApplicable =
+      disabledReason &&
+      disabledReason !== "pref" &&
+      disabledReason !== "session";
+    if (!alsoShowHidden && notApplicable) {
+      continue;
+    }
+
+    // create an updated table-row for the shim
+    const tr = document.createElement("tr");
+    tr.setAttribute("data-id", id);
+
+    let td = document.createElement("td");
+    td.innerText = name;
+    tr.appendChild(td);
+
+    td = document.createElement("td");
+    const a = document.createElement("a");
+    a.href = `https://bugzilla.mozilla.org/show_bug.cgi?id=${bug}`;
+    document.l10n.setAttributes(a, "label-more-information", { bug });
+    a.target = "_blank";
+    td.appendChild(a);
+    tr.appendChild(td);
+
+    td = document.createElement("td");
+    tr.appendChild(td);
+    const button = document.createElement("button");
+    document.l10n.setAttributes(
+      button,
+      disabledReason ? "label-enable" : "label-disable"
+    );
+    td.appendChild(button);
+
+    // is it already in the table?
+    const row = table.querySelector(`tr[data-id="${id}"]`);
+    if (row) {
+      row.replaceWith(tr);
+    } else {
+      table.appendChild(tr);
+    }
+  }
+
+  for (const table of tables) {
+    if (!table.querySelector("tr:not(.message)")) {
+      // no shims? then add a message that none are available for this platform/config
+      clearTableAndAddMessage(table, `text-no-${table.id}`);
+    } else {
+      // otherwise hide any such message, since we have shims on the list
+      hideMessagesOnTable(table);
+    }
+  }
+}
+
+function redrawTable(table, data, alsoShowHidden) {
+  const df = document.createDocumentFragment();
+  table.querySelectorAll("tr").forEach(tr => {
+    tr.remove();
+  });
+
+  let noEntriesMessage;
+  if (data === false) {
+    noEntriesMessage = "text-disabled-in-about-config";
+  } else if (data.length === 0) {
+    noEntriesMessage = `text-no-${table.id}`;
+  }
+
+  if (noEntriesMessage) {
+    const tr = document.createElement("tr");
+    df.appendChild(tr);
+
+    const td = document.createElement("td");
+    td.setAttribute("colspan", "3");
+    document.l10n.setAttributes(td, noEntriesMessage);
+    tr.appendChild(td);
+
+    table.appendChild(df);
+    return;
+  }
+
+  for (const row of data) {
+    if (row.hidden && !alsoShowHidden) {
+      continue;
+    }
+
+    const tr = document.createElement("tr");
+    tr.setAttribute("data-id", row.id);
+    df.appendChild(tr);
+
+    let td = document.createElement("td");
+    td.innerText = row.domain;
+    tr.appendChild(td);
+
+    td = document.createElement("td");
+    const a = document.createElement("a");
+    const bug = row.bug;
+    a.href = `https://bugzilla.mozilla.org/show_bug.cgi?id=${bug}`;
+    document.l10n.setAttributes(a, "label-more-information", { bug });
+    a.target = "_blank";
+    td.appendChild(a);
+    tr.appendChild(td);
+
+    td = document.createElement("td");
+    tr.appendChild(td);
+    const button = document.createElement("button");
+    document.l10n.setAttributes(
+      button,
+      row.active ? "label-disable" : "label-enable"
+    );
+    td.appendChild(button);
+  }
+  table.appendChild(df);
+}
+
+window.onhashchange = redraw;
diff --git a/browser/extensions/webcompat/about-compat/aboutPage.js b/browser/extensions/webcompat/about-compat/aboutPage.js
new file mode 100644
index 0000000000..0f2e7c4ad4
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/aboutPage.js
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global ExtensionAPI, XPCOMUtils */
+
+const Services =
+  globalThis.Services ||
+  ChromeUtils.import("resource://gre/modules/Services.jsm").Services;
+
+XPCOMUtils.defineLazyServiceGetter(
+  this,
+  "resProto",
+  "@mozilla.org/network/protocol;1?name=resource",
+  "nsISubstitutingProtocolHandler"
+);
+
+const ResourceSubstitution = "webcompat";
+const ProcessScriptURL = "resource://webcompat/aboutPageProcessScript.js";
+const ContractID = "@mozilla.org/network/protocol/about;1?what=compat";
+
+this.aboutPage = class extends ExtensionAPI {
+  onStartup() {
+    const { rootURI } = this.extension;
+
+    resProto.setSubstitution(
+      ResourceSubstitution,
+      Services.io.newURI("about-compat/", null, rootURI)
+    );
+
+    if (!(ContractID in Cc)) {
+      Services.ppmm.loadProcessScript(ProcessScriptURL, true);
+      this.processScriptRegistered = true;
+    }
+  }
+
+  onShutdown() {
+    resProto.setSubstitution(ResourceSubstitution, null);
+
+    if (this.processScriptRegistered) {
+      Services.ppmm.removeDelayedProcessScript(ProcessScriptURL);
+    }
+  }
+};
diff --git a/browser/extensions/webcompat/about-compat/aboutPage.json b/browser/extensions/webcompat/about-compat/aboutPage.json
new file mode 100644
index 0000000000..42e6114188
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/aboutPage.json
@@ -0,0 +1,6 @@
+[
+  {
+    "namespace": "aboutCompat",
+    "description": "Enables the about:compat page"
+  }
+]
diff --git a/browser/extensions/webcompat/about-compat/aboutPageProcessScript.js b/browser/extensions/webcompat/about-compat/aboutPageProcessScript.js
new file mode 100644
index 0000000000..13cb4fd0bf
--- /dev/null
+++ b/browser/extensions/webcompat/about-compat/aboutPageProcessScript.js
@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* eslint-env mozilla/process-script */
+
+"use strict";
+
+// Note: This script is used only when a static registration for our
+// component is not already present in the libxul binary.
+
+const Cm = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
+
+const classID = Components.ID("{97bf9550-2a7b-11e9-b56e-0800200c9a66}");
+
+if (!Cm.isCIDRegistered(classID)) {
+  const { ComponentUtils } = ChromeUtils.importESModule(
+    "resource://gre/modules/ComponentUtils.sys.mjs"
+  );
+
+  const factory = ComponentUtils.generateSingletonFactory(function () {
+    const { AboutCompat } = ChromeUtils.import(
+      "resource://webcompat/AboutCompat.jsm"
+    );
+    return new AboutCompat();
+  });
+
+  Cm.registerFactory(
+    classID,
+    "about:compat",
+    "@mozilla.org/network/protocol/about;1?what=compat",
+    factory
+  );
+}
diff --git a/browser/extensions/webcompat/components.conf b/browser/extensions/webcompat/components.conf
new file mode 100644
index 0000000000..ca5a6c3dbd
--- /dev/null
+++ b/browser/extensions/webcompat/components.conf
@@ -0,0 +1,17 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Note: This file will add static component registration entries for our
+# components to the libxul binary, though the actual component JSMs will be
+# packaged with the extension.
+Classes = [
+    {
+        'cid': '{97bf9550-2a7b-11e9-b56e-0800200c9a66}',
+        'contract_ids': ['@mozilla.org/network/protocol/about;1?what=compat'],
+        'jsm': 'resource://webcompat/AboutCompat.jsm',
+        'constructor': 'AboutCompat',
+    },
+]
diff --git a/browser/extensions/webcompat/data/injections.js b/browser/extensions/webcompat/data/injections.js
new file mode 100644
index 0000000000..3c0dc58bce
--- /dev/null
+++ b/browser/extensions/webcompat/data/injections.js
@@ -0,0 +1,1059 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals module, require */
+
+// This is a hack for the tests.
+if (typeof InterventionHelpers === "undefined") {
+  var InterventionHelpers = require("../lib/intervention_helpers");
+}
+
+/**
+ * For detailed information on our policies, and a documention on this format
+ * and its possibilites, please check the Mozilla-Wiki at
+ *
+ * https://wiki.mozilla.org/Compatibility/Go_Faster_Addon/Override_Policies_and_Workflows#User_Agent_overrides
+ */
+const AVAILABLE_INJECTIONS = [
+  {
+    id: "testbed-injection",
+    platform: "all",
+    domain: "webcompat-addon-testbed.herokuapp.com",
+    bug: "0000000",
+    hidden: true,
+    contentScripts: {
+      matches: ["*://webcompat-addon-testbed.herokuapp.com/*"],
+      css: [
+        {
+          file: "injections/css/bug0000000-testbed-css-injection.css",
+        },
+      ],
+      js: [
+        {
+          file: "injections/js/bug0000000-testbed-js-injection.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1452707",
+    platform: "all",
+    domain: "ib.absa.co.za",
+    bug: "1452707",
+    contentScripts: {
+      matches: ["https://ib.absa.co.za/*"],
+      js: [
+        {
+          file: "injections/js/bug1452707-window.controllers-shim-ib.absa.co.za.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1457335",
+    platform: "desktop",
+    domain: "histography.io",
+    bug: "1457335",
+    contentScripts: {
+      matches: ["*://histography.io/*"],
+      js: [
+        {
+          file: "injections/js/bug1457335-histography.io-ua-change.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1472075",
+    platform: "desktop",
+    domain: "bankofamerica.com",
+    bug: "1472075",
+    contentScripts: {
+      matches: [
+        "*://*.bankofamerica.com/*",
+        "*://*.ml.com/*", // #120104
+      ],
+      js: [
+        {
+          file: "injections/js/bug1472075-bankofamerica.com-ua-change.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1579159",
+    platform: "android",
+    domain: "m.tailieu.vn",
+    bug: "1579159",
+    contentScripts: {
+      matches: ["*://m.tailieu.vn/*", "*://m.elib.vn/*"],
+      js: [
+        {
+          file: "injections/js/bug1579159-m.tailieu.vn-pdfjs-worker-disable.js",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1583366",
+    platform: "desktop",
+    domain: "Download prompt for files with no content-type",
+    bug: "1583366",
+    data: {
+      urls: ["https://ads-us.rd.linksynergy.com/as.php*"],
+      contentType: {
+        name: "content-type",
+        value: "text/html; charset=utf-8",
+      },
+    },
+    customFunc: "noSniffFix",
+  },
+  {
+    id: "bug1570328",
+    platform: "android",
+    domain: "developer.apple.com",
+    bug: "1570328",
+    contentScripts: {
+      matches: ["*://developer.apple.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1570328-developer-apple.com-transform-scale.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1575000",
+    platform: "all",
+    domain: "apply.lloydsbank.co.uk",
+    bug: "1575000",
+    contentScripts: {
+      matches: ["*://apply.lloydsbank.co.uk/*"],
+      css: [
+        {
+          file: "injections/css/bug1575000-apply.lloydsbank.co.uk-radio-buttons-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1605611",
+    platform: "android",
+    domain: "maps.google.com",
+    bug: "1605611",
+    contentScripts: {
+      matches: InterventionHelpers.matchPatternsForGoogle(
+        "*://www.google.",
+        "/maps*"
+      ),
+      css: [
+        {
+          file: "injections/css/bug1605611-maps.google.com-directions-time.css",
+        },
+      ],
+      js: [
+        {
+          file: "injections/js/bug1605611-maps.google.com-directions-time.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1610344",
+    platform: "all",
+    domain: "directv.com.co",
+    bug: "1610344",
+    contentScripts: {
+      matches: [
+        "https://*.directv.com.co/*",
+        "https://*.directv.com.ec/*", // bug 1827706
+      ],
+      css: [
+        {
+          file: "injections/css/bug1610344-directv.com.co-hide-unsupported-message.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1644830",
+    platform: "desktop",
+    domain: "usps.com",
+    bug: "1644830",
+    contentScripts: {
+      matches: ["https://*.usps.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1644830-missingmail.usps.com-checkboxes-not-visible.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1651917",
+    platform: "android",
+    domain: "teletrader.com",
+    bug: "1651917",
+    contentScripts: {
+      matches: ["*://*.teletrader.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1651917-teletrader.com.body-transform-origin.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1653075",
+    platform: "desktop",
+    domain: "livescience.com",
+    bug: "1653075",
+    contentScripts: {
+      matches: ["*://*.livescience.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1653075-livescience.com-scrollbar-width.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1654877",
+    platform: "android",
+    domain: "preev.com",
+    bug: "1654877",
+    contentScripts: {
+      matches: ["*://preev.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1654877-preev.com-moz-appearance-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1654907",
+    platform: "android",
+    domain: "reactine.ca",
+    bug: "1654907",
+    contentScripts: {
+      matches: ["*://*.reactine.ca/*"],
+      css: [
+        {
+          file: "injections/css/bug1654907-reactine.ca-hide-unsupported.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1631811",
+    platform: "all",
+    domain: "datastudio.google.com",
+    bug: "1631811",
+    contentScripts: {
+      matches: ["https://datastudio.google.com/embed/reporting/*"],
+      js: [
+        {
+          file: "injections/js/bug1631811-datastudio.google.com-indexedDB.js",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1694470",
+    platform: "android",
+    domain: "m.myvidster.com",
+    bug: "1694470",
+    contentScripts: {
+      matches: ["https://m.myvidster.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1694470-myvidster.com-content-not-shown.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1731825",
+    platform: "desktop",
+    domain: "Office 365 email handling prompt",
+    bug: "1731825",
+    contentScripts: {
+      matches: [
+        "*://*.live.com/*",
+        "*://*.office.com/*",
+        "*://*.sharepoint.com/*",
+        "*://*.office365.com/*",
+      ],
+      js: [
+        {
+          file: "injections/js/bug1731825-office365-email-handling-prompt-autohide.js",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1707795",
+    platform: "desktop",
+    domain: "Office Excel spreadsheets",
+    bug: "1707795",
+    contentScripts: {
+      matches: [
+        "*://*.live.com/*",
+        "*://*.office.com/*",
+        "*://*.sharepoint.com/*",
+      ],
+      css: [
+        {
+          file: "injections/css/bug1707795-office365-sheets-overscroll-disable.css",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1712833",
+    platform: "all",
+    domain: "buskocchi.desuca.co.jp",
+    bug: "1712833",
+    contentScripts: {
+      matches: ["*://buskocchi.desuca.co.jp/*"],
+      css: [
+        {
+          file: "injections/css/bug1712833-buskocchi.desuca.co.jp-fix-map-height.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1722955",
+    platform: "android",
+    domain: "frontgate.com",
+    bug: "1722955",
+    contentScripts: {
+      matches: ["*://*.frontgate.com/*"],
+      js: [
+        {
+          file: "lib/ua_helpers.js",
+        },
+        {
+          file: "injections/js/bug1722955-frontgate.com-ua-override.js",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1724764",
+    platform: "android",
+    domain: "Issues related to missing window.print",
+    bug: "1724764",
+    contentScripts: {
+      matches: [
+        "*://*.edupage.org/*", // 1804477 and 1800118
+      ],
+      js: [
+        {
+          file: "injections/js/bug1724764-window-print.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1724868",
+    platform: "android",
+    domain: "news.yahoo.co.jp",
+    bug: "1724868",
+    contentScripts: {
+      matches: ["*://news.yahoo.co.jp/articles/*", "*://s.yimg.jp/*"],
+      js: [
+        {
+          file: "injections/js/bug1724868-news.yahoo.co.jp-ua-override.js",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1741234",
+    platform: "all",
+    domain: "patient.alphalabs.ca",
+    bug: "1741234",
+    contentScripts: {
+      matches: ["*://patient.alphalabs.ca/*"],
+      css: [
+        {
+          file: "injections/css/bug1741234-patient.alphalabs.ca-height-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1739489",
+    platform: "desktop",
+    domain: "Sites using draft.js",
+    bug: "1739489",
+    contentScripts: {
+      matches: [
+        "*://draftjs.org/*", // Bug 1739489
+        "*://www.facebook.com/*", // Bug 1739489
+        "*://twitter.com/*", // Bug 1776229
+        "*://mobile.twitter.com/*", // Bug 1776229
+        "*://*.reddit.com/*", // Bug 1829755
+      ],
+      js: [
+        {
+          file: "injections/js/bug1739489-draftjs-beforeinput.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1765947",
+    platform: "android",
+    domain: "veniceincoming.com",
+    bug: "1765947",
+    contentScripts: {
+      matches: ["*://veniceincoming.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1765947-veniceincoming.com-left-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug11769762",
+    platform: "all",
+    domain: "tiktok.com",
+    bug: "1769762",
+    contentScripts: {
+      matches: ["https://www.tiktok.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1769762-tiktok.com-plugins-shim.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1770962",
+    platform: "all",
+    domain: "coldwellbankerhomes.com",
+    bug: "1770962",
+    contentScripts: {
+      matches: ["*://*.coldwellbankerhomes.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1770962-coldwellbankerhomes.com-image-height.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1774490",
+    platform: "all",
+    domain: "rainews.it",
+    bug: "1774490",
+    contentScripts: {
+      matches: ["*://www.rainews.it/*"],
+      css: [
+        {
+          file: "injections/css/bug1774490-rainews.it-gallery-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1774005",
+    platform: "all",
+    domain: "Sites relying on window.InstallTrigger",
+    bug: "1774005",
+    contentScripts: {
+      matches: [
+        "*://*.crunchyroll.com/*", // Bug 1777597
+        "*://*.ersthelfer.tv/*", // Bug 1817520
+        "*://*.webex.com/*", // Bug 1788934
+        "*://ifcinema.institutfrancais.com/*", // Bug 1806423
+        "*://islamionline.islamicbank.ps/*", // Bug 1821439
+        "*://*.itv.com/*", // Bug 1830203
+        "*://mobilevikings.be/*/registration/*", // Bug 1797400
+        "*://www.schoolnutritionandfitness.com/*", // Bug 1793761
+      ],
+      js: [
+        {
+          file: "injections/js/bug1774005-installtrigger-shim.js",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1784302",
+    platform: "android",
+    domain: "open.toutiao.com",
+    bug: "1784302",
+    contentScripts: {
+      matches: ["*://open.toutiao.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1784302-effectiveType-shim.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1784141",
+    platform: "android",
+    domain: "aveeno.com and acuvue.com",
+    bug: "1784141",
+    contentScripts: {
+      matches: [
+        "*://*.aveeno.com/*",
+        "*://*.aveeno.ca/*",
+        "*://*.aveeno.com.au/*",
+        "*://*.aveeno.co.kr/*",
+        "*://*.aveeno.co.uk/*",
+        "*://*.aveeno.ie/*",
+        "*://*.acuvue.com/*", // 1804730
+        "*://*.acuvue.com.ar/*",
+        "*://*.acuvue.com.br/*",
+        "*://*.acuvue.ca/*",
+        "*://*.acuvue-fr.ca/*",
+        "*://*.acuvue.cl/*",
+        "*://*.acuvue.co.cr/*",
+        "*://*.acuvue.com.co/*",
+        "*://*.acuvue.com.do/*",
+        "*://*.acuvue.com.pe/*",
+        "*://*.acuvue.com.sv/*",
+        "*://*.acuvue.com.gt/*",
+        "*://*.acuvue.hn/*",
+        "*://*.acuvue.com.mx/*",
+        "*://*.acuvue.com.pa/*",
+        "*://*.acuvue.com.py/*",
+        "*://*.acuvue.com.pr/*",
+        "*://*.acuvue.com.uy/*",
+        "*://*.acuvue.com.au/*",
+        "*://*.acuvue.com.cn/*",
+        "*://*.acuvue.com.hk/*",
+        "*://*.acuvue.co.in/*",
+        "*://*.acuvue.co.id/*",
+        "*://acuvuevision.jp/*",
+        "*://*.acuvue.co.kr/*",
+        "*://*.acuvue.com.my/*",
+        "*://*.acuvue.co.nz/*",
+        "*://*.acuvue.com.sg/*",
+        "*://*.acuvue.com.tw/*",
+        "*://*.acuvue.co.th/*",
+        "*://*.acuvue.com.vn/*",
+        "*://*.acuvue.at/*",
+        "*://*.acuvue.be/*",
+        "*://*.fr.acuvue.be/*",
+        "*://*.acuvue-croatia.com/*",
+        "*://*.acuvue.cz/*",
+        "*://*.acuvue.dk/*",
+        "*://*.acuvue.fi/*",
+        "*://*.acuvue.fr/*",
+        "*://*.acuvue.de/*",
+        "*://*.acuvue.gr/*",
+        "*://*.acuvue.hu/*",
+        "*://*.acuvue.ie/*",
+        "*://*.acuvue.co.il/*",
+        "*://*.acuvue.it/*",
+        "*://*.acuvuekz.com/*",
+        "*://*.acuvue.lu/*",
+        "*://*.en.acuvuearabia.com/*",
+        "*://*.acuvuearabia.com/*",
+        "*://*.acuvue.nl/*",
+        "*://*.acuvue.no/*",
+        "*://*.acuvue.pl/*",
+        "*://*.acuvue.pt/*",
+        "*://*.acuvue.ro/*",
+        "*://*.acuvue.ru/*",
+        "*://*.acuvue.sk/*",
+        "*://*.acuvue.si/*",
+        "*://*.acuvue.co.za/*",
+        "*://*.jnjvision.com.tr/*",
+        "*://*.acuvue.co.uk/*",
+        "*://*.acuvue.ua/*",
+        "*://*.acuvue.com.pe/*",
+        "*://*.acuvue.es/*",
+        "*://*.acuvue.se/*",
+        "*://*.acuvue.ch/*",
+      ],
+      css: [
+        {
+          file: "injections/css/bug1784141-aveeno.com-acuvue.com-unsupported.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1784199",
+    platform: "all",
+    domain: "Sites based on Entrata Platform",
+    bug: "1784199",
+    contentScripts: {
+      matches: [
+        "*://*.aptsovation.com/*",
+        "*://*.avanabayview.com/*", // #118617
+        "*://*.breakpointeandcoronado.com/*", // #117735
+        "*://*.liveatlasathens.com/*", // #111189
+        "*://*.liveobserverpark.com/*", // #105244
+        "*://*.midwayurban.com/*", // #116523
+        "*://*.nhcalaska.com/*",
+        "*://*.prospectportal.com/*", // #115206
+        "*://*.securityproperties.com/*",
+        "*://*.theloftsorlando.com/*",
+        "*://*.vanallenapartments.com/*", // #120056
+      ],
+      css: [
+        {
+          file: "injections/css/bug1784199-entrata-platform-unsupported.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1795490",
+    platform: "android",
+    domain: "www.china-airlines.com",
+    bug: "1795490",
+    contentScripts: {
+      matches: ["*://www.china-airlines.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1795490-www.china-airlines.com-undisable-date-fields-on-mobile.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1799968",
+    platform: "linux",
+    domain: "www.samsung.com",
+    bug: "1799968",
+    contentScripts: {
+      matches: ["*://www.samsung.com/*/watches/*/*"],
+      js: [
+        {
+          file: "injections/js/bug1799968-www.samsung.com-appVersion-linux-fix.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1799980",
+    platform: "all",
+    domain: "healow.com",
+    bug: "1799980",
+    contentScripts: {
+      matches: ["*://healow.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1799980-healow.com-infinite-loop-fix.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1799994",
+    platform: "desktop",
+    domain: "www.vivobarefoot.com",
+    bug: "1799994",
+    contentScripts: {
+      matches: ["*://www.vivobarefoot.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1799994-www.vivobarefoot.com-product-filters-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1800000",
+    platform: "desktop",
+    domain: "www.honda.co.uk",
+    bug: "1800000",
+    contentScripts: {
+      matches: ["*://www.honda.co.uk/cars/book-a-service.html*"],
+      css: [
+        {
+          file: "injections/css/bug1800000-www.honda.co.uk-choose-dealer-button-fix.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1448747",
+    platform: "android",
+    domain: "FastClick breakage",
+    bug: "1448747",
+    contentScripts: {
+      matches: [
+        "*://*.co2meter.com/*", // 10959
+        "*://*.franmar.com/*", // 27273
+        "*://*.themusiclab.org/*", // 49667
+        "*://*.oregonfoodbank.org/*", // 53203
+        "*://*.fourbarrelcoffee.com/*", // 59427
+        "*://bluetokaicoffee.com/*", // 99867
+        "*://bathpublishing.com/*", // 100145
+        "*://dylantalkstone.com/*", // 101356
+        "*://renewd.com.au/*", // 104998
+        "*://*.lamudi.co.id/*", // 106767
+        "*://*.thehawksmoor.com/*", // 107549
+        "*://weaversofireland.com/*", // 116816
+        "*://*.iledefrance-mobilites.fr/*", // 117344
+        "*://*.lawnmowerpartsworld.com/*", // 117577
+        "*://*.discountcoffee.co.uk/*", // 118757
+        "*://torguard.net/*", // 120113
+        "*://*.arcsivr.com/*", // 120716
+      ],
+      js: [
+        {
+          file: "injections/js/bug1448747-fastclick-shim.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1818818",
+    platform: "android",
+    domain: "FastClick breakage - legacy",
+    bug: "1818818",
+    contentScripts: {
+      matches: [
+        "*://*.chatiw.com/*", // 5544
+        "*://*.wellcare.com/*", // 116595
+      ],
+      js: [
+        {
+          file: "injections/js/bug1818818-fastclick-legacy-shim.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1819476",
+    platform: "all",
+    domain: "axisbank.com",
+    bug: "1819476",
+    contentScripts: {
+      matches: ["*://*.axisbank.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1819476-axisbank.com-webkitSpeechRecognition-shim.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1819450",
+    platform: "android",
+    domain: "cmbchina.com",
+    bug: "1819450",
+    contentScripts: {
+      matches: ["*://www.cmbchina.com/*", "*://cmbchina.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1819450-cmbchina.com-ua-change.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1819678",
+    platform: "android",
+    domain: "cnki.net",
+    bug: "1819678",
+    contentScripts: {
+      matches: ["*://*.cnki.net/*"],
+      js: [
+        {
+          file: "injections/js/bug1819678-cnki.net-undisable-search-field.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1827678-webc77727",
+    platform: "android",
+    domain: "free4talk.com",
+    bug: "1827678",
+    contentScripts: {
+      matches: ["*://www.free4talk.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1819678-free4talk.com-window-chrome-shim.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1827678-webc119017",
+    platform: "desktop",
+    domain: "nppes.cms.hhs.gov",
+    bug: "1827678",
+    contentScripts: {
+      matches: ["*://nppes.cms.hhs.gov/*"],
+      css: [
+        {
+          file: "injections/css/bug1819678-nppes.cms.hhs.gov-unsupported-banner.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1830776",
+    platform: "all",
+    domain: "blueshieldca.com",
+    bug: "1830776",
+    contentScripts: {
+      matches: ["*://*.blueshieldca.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1830776-blueshieldca.com-unsupported.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1829949",
+    platform: "desktop",
+    domain: "tomshardware.com",
+    bug: "1829949",
+    contentScripts: {
+      matches: ["*://*.tomshardware.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1829949-tomshardware.com-scrollbar-width.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1829952",
+    platform: "android",
+    domain: "eventer.co.il",
+    bug: "1829952",
+    contentScripts: {
+      matches: ["*://*.eventer.co.il/*"],
+      css: [
+        {
+          file: "injections/css/bug1829952-eventer.co.il-button-height.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1830747",
+    platform: "android",
+    domain: "my.babbel.com",
+    bug: "1830747",
+    contentScripts: {
+      matches: ["*://my.babbel.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1830747-babbel.com-page-height.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1830752",
+    platform: "all",
+    domain: "afisha.ru",
+    bug: "1830752",
+    contentScripts: {
+      matches: ["*://*.afisha.ru/*"],
+      css: [
+        {
+          file: "injections/css/bug1830752-afisha.ru-slider-pointer-events.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1830761",
+    platform: "all",
+    domain: "91mobiles.com",
+    bug: "1830761",
+    contentScripts: {
+      matches: ["*://*.91mobiles.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1830761-91mobiles.com-content-height.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1830796",
+    platform: "android",
+    domain: "copyleaks.com",
+    bug: "1830796",
+    contentScripts: {
+      matches: ["*://*.copyleaks.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1830796-copyleaks.com-hide-unsupported.css",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1830810",
+    platform: "all",
+    domain: "interceramic.com",
+    bug: "1830810",
+    contentScripts: {
+      matches: ["*://interceramic.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1830810-interceramic.com-hide-unsupported.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1830813",
+    platform: "desktop",
+    domain: "onstove.com",
+    bug: "1830813",
+    contentScripts: {
+      matches: ["*://*.onstove.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1830813-page.onstove.com-hide-unsupported.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1831007",
+    platform: "all",
+    domain: "All international Nintendo domains",
+    bug: "1831007",
+    contentScripts: {
+      matches: [
+        "*://*.mojenintendo.cz/*",
+        "*://*.nintendo-europe.com/*",
+        "*://*.nintendo.at/*",
+        "*://*.nintendo.be/*",
+        "*://*.nintendo.ch/*",
+        "*://*.nintendo.co.il/*",
+        "*://*.nintendo.co.jp/*",
+        "*://*.nintendo.co.kr/*",
+        "*://*.nintendo.co.nz/*",
+        "*://*.nintendo.co.uk/*",
+        "*://*.nintendo.co.za/*",
+        "*://*.nintendo.com.au/*",
+        "*://*.nintendo.com.hk/*",
+        "*://*.nintendo.com/*",
+        "*://*.nintendo.de/*",
+        "*://*.nintendo.dk/*",
+        "*://*.nintendo.es/*",
+        "*://*.nintendo.fi/*",
+        "*://*.nintendo.fr/*",
+        "*://*.nintendo.gr/*",
+        "*://*.nintendo.hu/*",
+        "*://*.nintendo.it/*",
+        "*://*.nintendo.nl/*",
+        "*://*.nintendo.no/*",
+        "*://*.nintendo.pt/*",
+        "*://*.nintendo.ru/*",
+        "*://*.nintendo.se/*",
+        "*://*.nintendo.sk/*",
+        "*://*.nintendo.tw/*",
+        "*://*.nintendoswitch.com.cn/*",
+      ],
+      js: [
+        {
+          file: "injections/js/bug1831007-nintendo-window-OnetrustActiveGroups.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1836157",
+    platform: "android",
+    domain: "thai-masszazs.net",
+    bug: "1836157",
+    contentScripts: {
+      matches: ["*://www.thai-masszazs.net/en/*"],
+      js: [
+        {
+          file: "injections/js/bug1836157-thai-masszazs-niceScroll-disable.js",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1836103",
+    platform: "all",
+    domain: "autostar-novoross.ru",
+    bug: "1836103",
+    contentScripts: {
+      matches: ["*://autostar-novoross.ru/*"],
+      css: [
+        {
+          file: "injections/css/bug1836103-autostar-novoross.ru-make-map-taller.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1836105",
+    platform: "all",
+    domain: "cnn.com",
+    bug: "1836105",
+    contentScripts: {
+      matches: ["*://*.cnn.com/*"],
+      css: [
+        {
+          file: "injections/css/bug1836105-cnn.com-fix-blank-pages-when-printing.css",
+        },
+      ],
+    },
+  },
+  {
+    id: "bug1836177",
+    platform: "desktop",
+    domain: "clalit.co.il",
+    bug: "1836177",
+    contentScripts: {
+      matches: [
+        "*://e-services.clalit.co.il/OnlineWeb/General/InfoFullLogin.aspx*",
+      ],
+      css: [
+        {
+          file: "injections/css/bug1836177-clalit.co.il-hide-number-input-spinners.css",
+        },
+      ],
+      allFrames: true,
+    },
+  },
+  {
+    id: "bug1842437",
+    platform: "desktop",
+    domain: "www.youtube.com",
+    bug: "1842437",
+    contentScripts: {
+      matches: ["*://www.youtube.com/*"],
+      js: [
+        {
+          file: "injections/js/bug1842437-www.youtube.com-performance-now-precision.js",
+        },
+      ],
+    },
+  },
+];
+
+module.exports = AVAILABLE_INJECTIONS;
diff --git a/browser/extensions/webcompat/data/shims.js b/browser/extensions/webcompat/data/shims.js
new file mode 100644
index 0000000000..8e08dd6c95
--- /dev/null
+++ b/browser/extensions/webcompat/data/shims.js
@@ -0,0 +1,874 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals module, require */
+
+const AVAILABLE_SHIMS = [
+  {
+    hiddenInAboutCompat: true,
+    id: "LiveTestShim",
+    platform: "all",
+    name: "Live test shim",
+    bug: "livetest",
+    file: "live-test-shim.js",
+    matches: ["*://webcompat-addon-testbed.herokuapp.com/shims_test.js"],
+    needsShimHelpers: ["getOptions", "optIn"],
+  },
+  {
+    hiddenInAboutCompat: true,
+    id: "MochitestShim",
+    platform: "all",
+    branch: ["all:ignoredOtherPlatform"],
+    name: "Test shim for Mochitests",
+    bug: "mochitest",
+    file: "mochitest-shim-1.js",
+    matches: [
+      "*://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test.js",
+    ],
+    needsShimHelpers: ["getOptions", "optIn"],
+    options: {
+      simpleOption: true,
+      complexOption: { a: 1, b: "test" },
+      branchValue: { value: true, branches: [] },
+      platformValue: { value: true, platform: "neverUsed" },
+    },
+    unblocksOnOptIn: ["*://trackertest.org/*"],
+  },
+  {
+    hiddenInAboutCompat: true,
+    disabled: true,
+    id: "MochitestShim2",
+    platform: "all",
+    name: "Test shim for Mochitests (disabled by default)",
+    bug: "mochitest",
+    file: "mochitest-shim-2.js",
+    matches: [
+      "*://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test_2.js",
+    ],
+    needsShimHelpers: ["getOptions", "optIn"],
+    options: {
+      simpleOption: true,
+      complexOption: { a: 1, b: "test" },
+      branchValue: { value: true, branches: [] },
+      platformValue: { value: true, platform: "neverUsed" },
+    },
+    unblocksOnOptIn: ["*://trackertest.org/*"],
+  },
+  {
+    hiddenInAboutCompat: true,
+    id: "MochitestShim3",
+    platform: "all",
+    name: "Test shim for Mochitests (host)",
+    bug: "mochitest",
+    file: "mochitest-shim-3.js",
+    notHosts: ["example.com"],
+    matches: [
+      "*://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test_3.js",
+    ],
+  },
+  {
+    hiddenInAboutCompat: true,
+    id: "MochitestShim4",
+    platform: "all",
+    name: "Test shim for Mochitests (notHost)",
+    bug: "mochitest",
+    file: "mochitest-shim-3.js",
+    hosts: ["example.net"],
+    matches: [
+      "*://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test_3.js",
+    ],
+  },
+  {
+    hiddenInAboutCompat: true,
+    id: "MochitestShim5",
+    platform: "all",
+    name: "Test shim for Mochitests (branch)",
+    bug: "mochitest",
+    file: "mochitest-shim-3.js",
+    branches: ["never matches"],
+    matches: [
+      "*://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test_3.js",
+    ],
+  },
+  {
+    hiddenInAboutCompat: true,
+    id: "MochitestShim6",
+    platform: "never matches",
+    name: "Test shim for Mochitests (platform)",
+    bug: "mochitest",
+    file: "mochitest-shim-3.js",
+    matches: [
+      "*://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test_3.js",
+    ],
+  },
+  {
+    id: "AddThis",
+    platform: "all",
+    name: "AddThis",
+    bug: "1713694",
+    file: "addthis-angular.js",
+    matches: [
+      "*://s7.addthis.com/icons/official-addthis-angularjs/current/dist/official-addthis-angularjs.min.js*",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Adform",
+    platform: "all",
+    name: "Adform",
+    bug: "1713695",
+    file: "adform.js",
+    matches: [
+      "*://track.adform.net/serving/scripts/trackpoint/",
+      "*://track.adform.net/serving/scripts/trackpoint/async/",
+      {
+        patterns: ["*://track.adform.net/Serving/TrackPoint/*"],
+        target: "tracking-pixel.png",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "AdNexusAST",
+    platform: "all",
+    name: "AdNexus AST",
+    bug: "1734130",
+    file: "adnexus-ast.js",
+    matches: ["*://*.adnxs.com/*/ast.js*"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "AdNexusPrebid",
+    platform: "all",
+    name: "AdNexus Prebid",
+    bug: "1713696",
+    file: "adnexus-prebid.js",
+    matches: ["*://*.adnxs.com/*/pb.js*", "*://*.adnxs.com/*/prebid*"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "AdobeEverestJS",
+    platform: "all",
+    name: "Adobe EverestJS",
+    bug: "1728114",
+    file: "everest.js",
+    matches: ["*://www.everestjs.net/static/st.v3.js*"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    // keep this above AdSafeProtectedTrackingPixels
+    id: "AdSafeProtectedGoogleIMAAdapter",
+    platform: "all",
+    name: "Ad Safe Protected Google IMA Adapter",
+    bug: "1508639",
+    file: "adsafeprotected-ima.js",
+    matches: ["*://static.adsafeprotected.com/vans-adapter-google-ima.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "AdsByGoogle",
+    platform: "all",
+    name: "Ads by Google",
+    bug: "1713726",
+    file: "google-ads.js",
+    matches: [
+      "*://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js",
+      {
+        patterns: [
+          "*://pagead2.googlesyndication.com/pagead/*.js*fcd=true",
+          "*://pagead2.googlesyndication.com/pagead/js/*.js*fcd=true",
+        ],
+        target: "empty-script.js",
+        types: ["xmlhttprequest"],
+      },
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "AdvertisingCom",
+    platform: "all",
+    name: "advertising.com",
+    bug: "1701685",
+    matches: [
+      {
+        patterns: ["*://pixel.advertising.com/firefox-etp"],
+        target: "tracking-pixel.png",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+      {
+        patterns: ["*://cdn.cmp.advertising.com/firefox-etp"],
+        target: "empty-script.js",
+        types: ["xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+      {
+        patterns: ["*://*.advertising.com/*.js*"],
+        target: "https://cdn.cmp.advertising.com/firefox-etp",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+      {
+        patterns: ["*://*.advertising.com/*"],
+        target: "https://pixel.advertising.com/firefox-etp",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+    ],
+  },
+  {
+    id: "Branch",
+    platform: "all",
+    name: "Branch Web SDK",
+    bug: "1716220",
+    file: "branch.js",
+    matches: ["*://cdn.branch.io/branch-latest.min.js*"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "DoubleVerify",
+    platform: "all",
+    name: "DoubleVerify",
+    bug: "1771557",
+    file: "doubleverify.js",
+    matches: ["*://pub.doubleverify.com/signals/pub.js*"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "AmazonTAM",
+    platform: "all",
+    name: "Amazon Transparent Ad Marketplace",
+    bug: "1713698",
+    file: "apstag.js",
+    matches: ["*://c.amazon-adsystem.com/aax2/apstag.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "BmAuth",
+    platform: "all",
+    name: "BmAuth by 9c9media",
+    bug: "1486337",
+    file: "bmauth.js",
+    matches: ["*://auth.9c9media.ca/auth/main.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Chartbeat",
+    platform: "all",
+    name: "Chartbeat",
+    bug: "1713699",
+    file: "chartbeat.js",
+    matches: [
+      "*://static.chartbeat.com/js/chartbeat.js",
+      "*://static.chartbeat.com/js/chartbeat_video.js",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Criteo",
+    platform: "all",
+    name: "Criteo",
+    bug: "1713720",
+    file: "criteo.js",
+    matches: ["*://static.criteo.net/js/ld/publishertag.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    // keep this above AdSafeProtectedTrackingPixels
+    id: "Doubleclick",
+    platform: "all",
+    name: "Doubleclick",
+    bug: "1713693",
+    matches: [
+      {
+        patterns: [
+          "*://securepubads.g.doubleclick.net/gampad/*ad-blk*",
+          "*://pubads.g.doubleclick.net/gampad/*ad-blk*",
+        ],
+        target: "empty-shim.txt",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+      {
+        patterns: [
+          "*://securepubads.g.doubleclick.net/gampad/*xml_vmap1*",
+          "*://pubads.g.doubleclick.net/gampad/*xml_vmap1*",
+        ],
+        target: "vmad.xml",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+      {
+        patterns: [
+          "*://vast.adsafeprotected.com/vast*",
+          "*://securepubads.g.doubleclick.net/gampad/*xml_vmap2*",
+          "*://pubads.g.doubleclick.net/gampad/*xml_vmap2*",
+        ],
+        target: "vast2.xml",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+      {
+        patterns: [
+          "*://securepubads.g.doubleclick.net/gampad/*ad*",
+          "*://pubads.g.doubleclick.net/gampad/*ad*",
+        ],
+        target: "vast3.xml",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "PBMWebAPIFixes",
+    platform: "all",
+    name: "Private Browsing Web APIs",
+    bug: "1773110",
+    runFirst: "private-browsing-web-api-fixes.js",
+    matches: [
+      "*://*.imgur.com/js/vendor.*.bundle.js",
+      "*://*.imgur.io/js/vendor.*.bundle.js",
+      "*://www.rva311.com/static/js/main.*.chunk.js",
+      "*://web-assets.toggl.com/app/assets/scripts/*.js", // bug 1783919
+    ],
+    onlyIfPrivateBrowsing: true,
+  },
+  {
+    id: "Eluminate",
+    platform: "all",
+    name: "Eluminate",
+    bug: "1503211",
+    file: "eluminate.js",
+    matches: ["*://libs.coremetrics.com/eluminate.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "FacebookSDK",
+    platform: "all",
+    branches: ["nightly:android"],
+    name: "Facebook SDK",
+    bug: "1226498",
+    file: "facebook-sdk.js",
+    logos: ["facebook.svg", "play.svg"],
+    matches: [
+      "*://connect.facebook.net/*/sdk.js*",
+      "*://connect.facebook.net/*/all.js*",
+      {
+        patterns: ["*://www.facebook.com/platform/impression.php*"],
+        target: "tracking-pixel.png",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+    ],
+    needsShimHelpers: ["optIn", "getOptions"],
+    onlyIfBlockedByETP: true,
+    unblocksOnOptIn: [
+      "*://connect.facebook.net/*/sdk.js*",
+      "*://connect.facebook.net/*/all.js*",
+      "*://*.xx.fbcdn.net/*", // covers:
+      // "*://scontent-.*-\d.xx.fbcdn.net/*",
+      // "*://static.xx.fbcdn.net/rsrc.php/*",
+      "*://graph.facebook.com/v2*access_token*",
+      "*://graph.facebook.com/v*/me*",
+      "*://graph.facebook.com/*/picture*",
+      "*://www.facebook.com/*/plugins/login_button.php*",
+      "*://www.facebook.com/x/oauth/status*",
+      {
+        patterns: [
+          "*://www.facebook.com/*/plugins/video.php*",
+          "*://www.facebook.com/rsrc.php/*",
+        ],
+        branches: ["nightly"],
+      },
+    ],
+  },
+  {
+    id: "Fastclick",
+    platform: "all",
+    name: "Fastclick",
+    bug: "1738220",
+    file: "fastclick.js",
+    matches: [
+      "*://secure.cdn.fastclick.net/js/cnvr-launcher/*/launcher-stub.min.js*",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GoogleAnalyticsAndTagManager",
+    platform: "all",
+    name: "Google Analytics and Tag Manager",
+    bug: "1713687",
+    file: "google-analytics-and-tag-manager.js",
+    matches: [
+      "*://www.google-analytics.com/analytics.js*",
+      "*://www.google-analytics.com/gtm/js*",
+      "*://www.googletagmanager.com/gtm.js*",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GoogleAnalyticsECommercePlugin",
+    platform: "all",
+    name: "Google Analytics E-Commerce Plugin",
+    bug: "1620533",
+    file: "google-analytics-ecommerce-plugin.js",
+    matches: ["*://www.google-analytics.com/plugins/ua/ec.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GoogleAnalyticsLegacy",
+    platform: "all",
+    name: "Google Analytics (legacy version)",
+    bug: "1487072",
+    file: "google-analytics-legacy.js",
+    matches: ["*://ssl.google-analytics.com/ga.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GoogleIMA",
+    platform: "all",
+    name: "Google Interactive Media Ads",
+    bug: "1713690",
+    file: "google-ima.js",
+    matches: [
+      "*://s0.2mdn.net/instream/html5/ima3.js",
+      "*://imasdk.googleapis.com/js/sdkloader/ima3.js",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GooglePageAd",
+    platform: "all",
+    name: "Google Page Ad",
+    bug: "1713692",
+    file: "google-page-ad.js",
+    matches: ["*://www.googleadservices.com/pagead/conversion_async.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GooglePublisherTags",
+    platform: "all",
+    name: "Google Publisher Tags",
+    bug: "1713685",
+    file: "google-publisher-tags.js",
+    matches: [
+      "*://www.googletagservices.com/tag/js/gpt.js*",
+      "*://pagead2.googlesyndication.com/tag/js/gpt.js*",
+      "*://pagead2.googlesyndication.com/gpt/pubads_impl_*.js*",
+      "*://securepubads.g.doubleclick.net/tag/js/gpt.js*",
+      "*://securepubads.g.doubleclick.net/gpt/pubads_impl_*.js*",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Google SafeFrame",
+    platform: "all",
+    name: "Google SafeFrame",
+    bug: "1713691",
+    matches: [
+      {
+        patterns: [
+          "*://tpc.googlesyndication.com/safeframe/*/html/container.html",
+          "*://*.safeframe.googlesyndication.com/safeframe/*/html/container.html",
+        ],
+        target: "google-safeframe.html",
+        types: ["sub_frame"],
+      },
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "GoogleTrends",
+    platform: "all",
+    name: "Google Trends",
+    bug: "1624914",
+    custom: "google-trends-dfpi-fix",
+    onlyIfDFPIActive: true,
+    matches: [
+      {
+        patterns: ["*://trends.google.com/trends/embed*"],
+        types: ["sub_frame"],
+      },
+    ],
+  },
+  {
+    id: "IAM",
+    platform: "all",
+    name: "INFOnline IAM",
+    bug: "1761774",
+    file: "iam.js",
+    matches: ["*://script.ioam.de/iam.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    // keep this above AdSafeProtectedTrackingPixels
+    id: "IASPET",
+    platform: "all",
+    name: "Integral Ad Science PET",
+    bug: "1713701",
+    file: "iaspet.js",
+    matches: [
+      "*://cdn.adsafeprotected.com/iasPET.1.js",
+      "*://static.adsafeprotected.com/iasPET.1.js",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "MNet",
+    platform: "all",
+    name: "Media.net Ads",
+    bug: "1713703",
+    file: "empty-script.js",
+    matches: ["*://adservex.media.net/videoAds.js*"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Moat",
+    platform: "all",
+    name: "Moat",
+    bug: "1713704",
+    file: "moat.js",
+    matches: [
+      "*://*.moatads.com/*/moatad.js*",
+      "*://*.moatads.com/*/moatapi.js*",
+      "*://*.moatads.com/*/moatheader.js*",
+      "*://*.moatads.com/*/yi.js*",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Nielsen",
+    platform: "all",
+    name: "Nielsen",
+    bug: "1760754",
+    file: "nielsen.js",
+    matches: ["*://*.imrworldwide.com/v60.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Optimizely",
+    platform: "all",
+    name: "Optimizely",
+    bug: "1714431",
+    file: "optimizely.js",
+    matches: [
+      "*://cdn.optimizely.com/js/*.js",
+      "*://cdn.optimizely.com/public/*.js",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Rambler",
+    platform: "all",
+    name: "Rambler Authenticator",
+    bug: "1606428",
+    file: "rambler-authenticator.js",
+    matches: ["*://id.rambler.ru/rambler-id-helper/auth_events.js"],
+    needsShimHelpers: ["optIn"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "RichRelevance",
+    platform: "all",
+    name: "Rich Relevance",
+    bug: "1713725",
+    file: "rich-relevance.js",
+    matches: ["*://media.richrelevance.com/rrserver/js/1.2/p13n.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Firebase",
+    platform: "all",
+    name: "Firebase",
+    bug: "1771783",
+    onlyIfPrivateBrowsing: true,
+    runFirst: "firebase.js",
+    matches: [
+      // bugs 1750699, 1767407
+      "*://www.gstatic.com/firebasejs/*/firebase-messaging.js*",
+    ],
+    contentScripts: [
+      {
+        cookieStoreId: "firefox-private",
+        js: "firebase.js",
+        runAt: "document_start",
+        matches: [
+          "*://www.homedepot.ca/*", // bug 1778993
+          "*://orangerie.eu/*", // bug 1758442
+          "*://web.whatsapp.com/*", // bug 1767407
+          "*://www.tripadvisor.com/*", // bug 1779536
+          "*://www.office.com/*", // bug 1783921
+        ],
+      },
+    ],
+  },
+  {
+    id: "StickyAdsTV",
+    platform: "all",
+    name: "StickyAdsTV",
+    bug: "1717806",
+    matches: [
+      {
+        patterns: ["https://ads.stickyadstv.com/firefox-etp"],
+        target: "tracking-pixel.png",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+      {
+        patterns: [
+          "*://ads.stickyadstv.com/auto-user-sync*",
+          "*://ads.stickyadstv.com/user-matching*",
+        ],
+        target: "https://ads.stickyadstv.com/firefox-etp",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+    ],
+  },
+  {
+    id: "Vidible",
+    branch: ["nightly"],
+    platform: "all",
+    name: "Vidible",
+    bug: "1713710",
+    file: "vidible.js",
+    logos: ["play.svg"],
+    matches: [
+      "*://*.vidible.tv/*/vidible-min.js*",
+      "*://vdb-cdn-files.s3.amazonaws.com/*/vidible-min.js*",
+    ],
+    needsShimHelpers: ["optIn"],
+    onlyIfBlockedByETP: true,
+    unblocksOnOptIn: [
+      "*://delivery.vidible.tv/jsonp/pid=*/vid=*/*.js*",
+      "*://delivery.vidible.tv/placement/*",
+      "*://img.vidible.tv/prod/*",
+      "*://cdn-ssl.vidible.tv/prod/player/js/*.js",
+      "*://hlsrv.vidible.tv/prod/*.m3u8*",
+      "*://videos.vidible.tv/prod/*.key*",
+      "*://videos.vidible.tv/prod/*.mp4*",
+      "*://videos.vidible.tv/prod/*.webm*",
+      "*://videos.vidible.tv/prod/*.ts*",
+    ],
+  },
+  {
+    id: "Kinja",
+    platform: "all",
+    name: "Kinja",
+    bug: "1656171",
+    contentScripts: [
+      {
+        js: "kinja.js",
+        matches: [
+          "*://www.avclub.com/*",
+          "*://deadspin.com/*",
+          "*://gizmodo.com/*",
+          "*://jalopnik.com/*",
+          "*://jezebel.com/*",
+          "*://kotaku.com/*",
+          "*://lifehacker.com/*",
+          "*://www.theonion.com/*",
+          "*://www.theroot.com/*",
+          "*://thetakeout.com/*",
+          "*://theinventory.com/*",
+        ],
+        runAt: "document_start",
+        allFrames: true,
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+  {
+    id: "MicrosoftLogin",
+    platform: "desktop",
+    name: "Microsoft Login",
+    bug: "1638383",
+    requestStorageAccessForRedirect: [
+      ["*://web.powerva.microsoft.com/*", "*://login.microsoftonline.com/*"],
+      ["*://teams.microsoft.com/*", "*://login.microsoftonline.com/*"],
+      ["*://*.teams.microsoft.us/*", "*://login.microsoftonline.us/*"],
+    ],
+    contentScripts: [
+      {
+        js: "microsoftLogin.js",
+        matches: [
+          "*://web.powerva.microsoft.com/*",
+          "*://teams.microsoft.com/*",
+          "*://*.teams.microsoft.us/*",
+        ],
+        runAt: "document_start",
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+  {
+    id: "MicrosoftVirtualAssistant",
+    platform: "all",
+    name: "Microsoft Virtual Assistant",
+    bug: "1801277",
+    contentScripts: [
+      {
+        js: "microsoftVirtualAssistant.js",
+        matches: ["*://publisher.liveperson.net/*"],
+        runAt: "document_start",
+        allFrames: true,
+      },
+    ],
+  },
+  {
+    id: "History",
+    platform: "all",
+    name: "History.com",
+    bug: "1624853",
+    contentScripts: [
+      {
+        js: "history.js",
+        matches: ["*://play.history.com/*"],
+        runAt: "document_start",
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+  {
+    id: "Crave.ca",
+    platform: "all",
+    name: "Crave.ca",
+    bug: "1746439",
+    contentScripts: [
+      {
+        js: "crave-ca.js",
+        matches: ["*://account.bellmedia.ca/login*"],
+        runAt: "document_start",
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+  {
+    id: "Instagram.com",
+    platform: "android",
+    name: "Instagram.com",
+    bug: "1804445",
+    contentScripts: [
+      {
+        js: "instagram.js",
+        matches: ["*://www.instagram.com/*"],
+        runAt: "document_start",
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+  {
+    id: "MaxMindGeoIP",
+    platform: "all",
+    name: "MaxMind GeoIP",
+    bug: "1754389",
+    file: "maxmind-geoip.js",
+    matches: ["*://js.maxmind.com/js/apis/geoip2/*/geoip2.js"],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "WebTrends",
+    platform: "all",
+    name: "WebTrends",
+    bug: "1766414",
+    file: "webtrends.js",
+    matches: [
+      "*://s.webtrends.com/js/advancedLinkTracking.js",
+      "*://s.webtrends.com/js/webtrends.js",
+      "*://s.webtrends.com/js/webtrends.min.js",
+    ],
+    onlyIfBlockedByETP: true,
+  },
+  {
+    id: "Blogger",
+    platform: "all",
+    name: "Blogger",
+    bug: "1776869",
+    contentScripts: [
+      {
+        js: "blogger.js",
+        matches: ["*://www.blogger.com/comment/frame/*"],
+        runAt: "document_start",
+        allFrames: true,
+      },
+      {
+        js: "bloggerAccount.js",
+        matches: ["*://www.blogger.com/blog/*"],
+        runAt: "document_end",
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+  {
+    // keep this below any other shims checking adsafeprotected URLs
+    id: "AdSafeProtectedTrackingPixels",
+    platform: "all",
+    name: "Ad Safe Protected tracking pixels",
+    bug: "1717806",
+    matches: [
+      {
+        patterns: ["https://static.adsafeprotected.com/firefox-etp-pixel"],
+        target: "tracking-pixel.png",
+        types: ["image", "imageset", "xmlhttprequest"],
+      },
+      {
+        patterns: ["https://static.adsafeprotected.com/firefox-etp-js"],
+        target: "empty-script.js",
+        types: ["xmlhttprequest"],
+      },
+      {
+        patterns: [
+          "*://*.adsafeprotected.com/*.gif*",
+          "*://*.adsafeprotected.com/*.png*",
+        ],
+        target: "https://static.adsafeprotected.com/firefox-etp-pixel",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+      {
+        patterns: [
+          "*://*.adsafeprotected.com/*.js*",
+          "*://*.adsafeprotected.com/*/adj*",
+          "*://*.adsafeprotected.com/*/imp/*",
+          "*://*.adsafeprotected.com/*/Serving/*",
+          "*://*.adsafeprotected.com/*/unit/*",
+          "*://*.adsafeprotected.com/jload",
+          "*://*.adsafeprotected.com/jload?*",
+          "*://*.adsafeprotected.com/jsvid",
+          "*://*.adsafeprotected.com/jsvid?*",
+          "*://*.adsafeprotected.com/mon*",
+          "*://*.adsafeprotected.com/tpl",
+          "*://*.adsafeprotected.com/tpl?*",
+          "*://*.adsafeprotected.com/services/pub*",
+        ],
+        target: "https://static.adsafeprotected.com/firefox-etp-js",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+      {
+        // note, fallback case seems to be an image
+        patterns: ["*://*.adsafeprotected.com/*"],
+        target: "https://static.adsafeprotected.com/firefox-etp-pixel",
+        types: ["image", "imageset", "xmlhttprequest"],
+        onlyIfBlockedByETP: true,
+      },
+    ],
+  },
+  {
+    id: "SpotifyEmbed",
+    platform: "all",
+    name: "SpotifyEmbed",
+    bug: "1792395",
+    contentScripts: [
+      {
+        js: "spotify-embed.js",
+        matches: ["*://open.spotify.com/embed/*"],
+        runAt: "document_start",
+        allFrames: true,
+      },
+    ],
+    onlyIfDFPIActive: true,
+  },
+];
+
+module.exports = AVAILABLE_SHIMS;
diff --git a/browser/extensions/webcompat/data/ua_overrides.js b/browser/extensions/webcompat/data/ua_overrides.js
new file mode 100644
index 0000000000..150d13465d
--- /dev/null
+++ b/browser/extensions/webcompat/data/ua_overrides.js
@@ -0,0 +1,1371 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser, module, require */
+
+// This is a hack for the tests.
+if (typeof InterventionHelpers === "undefined") {
+  var InterventionHelpers = require("../lib/intervention_helpers");
+}
+if (typeof UAHelpers === "undefined") {
+  var UAHelpers = require("../lib/ua_helpers");
+}
+
+/**
+ * For detailed information on our policies, and a documention on this format
+ * and its possibilites, please check the Mozilla-Wiki at
+ *
+ * https://wiki.mozilla.org/Compatibility/Go_Faster_Addon/Override_Policies_and_Workflows#User_Agent_overrides
+ */
+const AVAILABLE_UA_OVERRIDES = [
+  {
+    id: "testbed-override",
+    platform: "all",
+    domain: "webcompat-addon-testbed.herokuapp.com",
+    bug: "0000000",
+    config: {
+      hidden: true,
+      matches: ["*://webcompat-addon-testbed.herokuapp.com/*"],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36 for WebCompat"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1577519 - directv.com - Create a UA override for directv.com for playback on desktop
+     * WebCompat issue #3846 - https://webcompat.com/issues/3846
+     *
+     * directv.com (attwatchtv.com) is blocking Firefox via UA sniffing. Spoofing as Chrome allows
+     * to access the site and playback works fine. This is former directvnow.com
+     */
+    id: "bug1577519",
+    platform: "desktop",
+    domain: "directv.com",
+    bug: "1577519",
+    config: {
+      matches: [
+        "*://*.attwatchtv.com/*",
+        "*://*.directv.com.ec/*", // bug 1827706
+        "*://*.directv.com/*",
+      ],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1570108 - steamcommunity.com - UA override for steamcommunity.com
+     * WebCompat issue #34171 - https://webcompat.com/issues/34171
+     *
+     * steamcommunity.com blocks chat feature for Firefox users showing unsupported browser message.
+     * When spoofing as Chrome the chat works fine
+     */
+    id: "bug1570108",
+    platform: "desktop",
+    domain: "steamcommunity.com",
+    bug: "1570108",
+    config: {
+      matches: ["*://steamcommunity.com/chat*"],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1582582 - sling.com - UA override for sling.com
+     * WebCompat issue #17804 - https://webcompat.com/issues/17804
+     *
+     * sling.com blocks Firefox users showing unsupported browser message.
+     * When spoofing as Chrome playing content works fine
+     */
+    id: "bug1582582",
+    platform: "desktop",
+    domain: "sling.com",
+    bug: "1582582",
+    config: {
+      matches: ["https://watch.sling.com/*", "https://www.sling.com/*"],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1610026 - www.mobilesuica.com - UA override for www.mobilesuica.com
+     * WebCompat issue #4608 - https://webcompat.com/issues/4608
+     *
+     * mobilesuica.com showing unsupported message for Firefox users
+     * Spoofing as Chrome allows to access the page
+     */
+    id: "bug1610026",
+    platform: "all",
+    domain: "www.mobilesuica.com",
+    bug: "1610026",
+    config: {
+      matches: ["https://www.mobilesuica.com/*"],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1385206 - Create UA override for rakuten.co.jp on Firefox Android
+     * (Imported from ua-update.json.in)
+     *
+     * rakuten.co.jp serves a Desktop version if Firefox is included in the UA.
+     */
+    id: "bug1385206",
+    platform: "android",
+    domain: "rakuten.co.jp",
+    bug: "1385206",
+    config: {
+      matches: ["*://*.rakuten.co.jp/*"],
+      uaTransformer: originalUA => {
+        return originalUA.replace(/Firefox.+$/, "");
+      },
+    },
+  },
+  {
+    /*
+     * Bug 969844 - mobile.de sends desktop site to Firefox on Android
+     *
+     * mobile.de sends the desktop site to Firefox Mobile.
+     * Spoofing as Chrome works fine.
+     */
+    id: "bug969844",
+    platform: "android",
+    domain: "mobile.de",
+    bug: "969844",
+    config: {
+      matches: ["*://*.mobile.de/*"],
+      uaTransformer: _ => {
+        return "Mozilla/5.0 (Linux; Android 6.0.1; SM-G920F Build/MMB29K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.91 Mobile Safari/537.36";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1509873 - zmags.com - Add UA override for secure.viewer.zmags.com
+     * WebCompat issue #21576 - https://webcompat.com/issues/21576
+     *
+     * The zmags viewer locks out Firefox Mobile with a "Browser unsupported"
+     * message, but tests showed that it works just fine with a Chrome UA.
+     * Outreach attempts were unsuccessful, and as the site has a relatively
+     * high rank, we alter the UA.
+     */
+    id: "bug1509873",
+    platform: "android",
+    domain: "zmags.com",
+    bug: "1509873",
+    config: {
+      matches: ["*://*.viewer.zmags.com/*"],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.91 Mobile Safari/537.36"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1574522 - UA override for enuri.com on Firefox for Android
+     * WebCompat issue #37139 - https://webcompat.com/issues/37139
+     *
+     * enuri.com returns a different template for Firefox on Android
+     * based on server side UA detection. This results in page content cut offs.
+     * Spoofing as Chrome fixes the issue
+     */
+    id: "bug1574522",
+    platform: "android",
+    domain: "enuri.com",
+    bug: "1574522",
+    config: {
+      matches: ["*://enuri.com/*"],
+      uaTransformer: _ => {
+        return "Mozilla/5.0 (Linux; Android 6.0.1; SM-G900M) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.111 Mobile Safari/537.36";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1574564 - UA override for ceskatelevize.cz on Firefox for Android
+     * WebCompat issue #15467 - https://webcompat.com/issues/15467
+     *
+     * ceskatelevize sets streamingProtocol depending on the User-Agent it sees
+     * in the request headers, returning DASH for Chrome, HLS for iOS,
+     * and Flash for Firefox Mobile. Since Mobile has no Flash, the video
+     * doesn't work. Spoofing as Chrome makes the video play
+     */
+    id: "bug1574564",
+    platform: "android",
+    domain: "ceskatelevize.cz",
+    bug: "1574564",
+    config: {
+      matches: ["*://*.ceskatelevize.cz/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1577267 - UA override for metfone.com.kh on Firefox for Android
+     * WebCompat issue #16363 - https://webcompat.com/issues/16363
+     *
+     * metfone.com.kh has a server side UA detection which returns desktop site
+     * for Firefox for Android. Spoofing as Chrome allows to receive mobile version
+     */
+    id: "bug1577267",
+    platform: "android",
+    domain: "metfone.com.kh",
+    bug: "1577267",
+    config: {
+      matches: ["*://*.metfone.com.kh/*"],
+      uaTransformer: originalUA => {
+        return (
+          UAHelpers.getPrefix(originalUA) +
+          " AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.111 Mobile Safari/537.36"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1598198 - User Agent extension for Samsung's galaxy.store URLs
+     *
+     * Samsung's galaxy.store shortlinks are supposed to redirect to a Samsung
+     * intent:// URL on Samsung devices, but to an error page on other brands.
+     * As we do not provide device info in our user agent string, this check
+     * fails, and even Samsung users land on an error page if they use Firefox
+     * for Android.
+     * This intervention adds a simple "Samsung" identifier to the User Agent
+     * on only the Galaxy Store URLs if the device happens to be a Samsung.
+     */
+    id: "bug1598198",
+    platform: "android",
+    domain: "galaxy.store",
+    bug: "1598198",
+    config: {
+      matches: [
+        "*://galaxy.store/*",
+        "*://dev.galaxy.store/*",
+        "*://stg.galaxy.store/*",
+      ],
+      uaTransformer: originalUA => {
+        if (!browser.systemManufacturer) {
+          return originalUA;
+        }
+
+        const manufacturer = browser.systemManufacturer.getManufacturer();
+        if (manufacturer && manufacturer.toLowerCase() === "samsung") {
+          return originalUA.replace("Mobile;", "Mobile; Samsung;");
+        }
+
+        return originalUA;
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1595215 - UA overrides for Uniqlo sites
+     * Webcompat issue #38825 - https://webcompat.com/issues/38825
+     *
+     * To receive the proper mobile version instead of the desktop version or
+     * avoid redirect loop, the UA is spoofed.
+     */
+    id: "bug1595215",
+    platform: "android",
+    domain: "uniqlo.com",
+    bug: "1595215",
+    config: {
+      matches: ["*://*.uniqlo.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Mobile Safari";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1622063 - UA override for wp1-ext.usps.gov
+     * Webcompat issue #29867 - https://webcompat.com/issues/29867
+     *
+     * The Job Search site for USPS does not work for Firefox Mobile
+     * browsers (a 500 is returned).
+     */
+    id: "bug1622063",
+    platform: "android",
+    domain: "wp1-ext.usps.gov",
+    bug: "1622063",
+    config: {
+      matches: ["*://wp1-ext.usps.gov/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1697324 - Update the override for mobile2.bmo.com
+     * Previously Bug 1622081 - UA override for mobile2.bmo.com
+     * Webcompat issue #45019 - https://webcompat.com/issues/45019
+     *
+     * Unless the UA string contains "Chrome", mobile2.bmo.com will
+     * display a modal saying the browser is out-of-date.
+     */
+    id: "bug1697324",
+    platform: "android",
+    domain: "mobile2.bmo.com",
+    bug: "1697324",
+    config: {
+      matches: ["*://mobile2.bmo.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1628455 - UA override for autotrader.ca
+     * Webcompat issue #50961 - https://webcompat.com/issues/50961
+     *
+     * autotrader.ca is showing desktop site for Firefox on Android
+     * based on server side UA detection. Spoofing as Chrome allows to
+     * get mobile experience
+     */
+    id: "bug1628455",
+    platform: "android",
+    domain: "autotrader.ca",
+    bug: "1628455",
+    config: {
+      matches: ["https://*.autotrader.ca/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1646791 - bancosantander.es - Re-add UA override.
+     * Bug 1665129 - *.gruposantander.es - Add wildcard domains.
+     * WebCompat issue #33462 - https://webcompat.com/issues/33462
+     * SuMo request - https://support.mozilla.org/es/questions/1291085
+     *
+     * santanderbank expects UA to have 'like Gecko', otherwise it runs
+     * xmlDoc.onload whose support has been dropped. It results in missing labels in forms
+     * and some other issues.  Adding 'like Gecko' fixes those issues.
+     */
+    id: "bug1646791",
+    platform: "all",
+    domain: "santanderbank.com",
+    bug: "1646791",
+    config: {
+      matches: [
+        "*://*.bancosantander.es/*",
+        "*://*.gruposantander.es/*",
+        "*://*.santander.co.uk/*",
+      ],
+      uaTransformer: originalUA => {
+        // The first line related to Firefox 100 is for Bug 1743445.
+        // [TODO]: Remove when bug 1743429 gets backed out.
+        return UAHelpers.capVersionTo99(originalUA).replace(
+          "Gecko",
+          "like Gecko"
+        );
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1651292 - UA override for www.jp.square-enix.com
+     * Webcompat issue #53018 - https://webcompat.com/issues/53018
+     *
+     * Unless the UA string contains "Chrome 66+", a section of
+     * www.jp.square-enix.com will show a never ending LOADING
+     * page.
+     */
+    id: "bug1651292",
+    platform: "android",
+    domain: "www.jp.square-enix.com",
+    bug: "1651292",
+    config: {
+      matches: ["*://www.jp.square-enix.com/music/sem/page/FF7R/ost/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome/83";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1666754 - Mobile UA override for lffl.org
+     * Bug 1665720 - lffl.org article page takes 2x as much time to load on Moto G
+     *
+     * This site returns desktop site based on server side UA detection.
+     * Spoofing as Chrome allows to get mobile experience
+     */
+    id: "bug1666754",
+    platform: "android",
+    domain: "lffl.org",
+    bug: "1666754",
+    config: {
+      matches: ["*://*.lffl.org/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1704673 - Add UA override for app.xiaomi.com
+     * Webcompat issue #66163 - https://webcompat.com/issues/66163
+     *
+     * The page isn’t redirecting properly error message received.
+     * Spoofing as Chrome makes the page load
+     */
+    id: "bug1704673",
+    platform: "android",
+    domain: "app.xiaomi.com",
+    bug: "1704673",
+    config: {
+      matches: ["*://app.xiaomi.com/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1712807 - Add UA override for www.dealnews.com
+     * Webcompat issue #39341 - https://webcompat.com/issues/39341
+     *
+     * The sites shows Firefox a different layout compared to Chrome.
+     * Spoofing as Chrome fixes this.
+     */
+    id: "bug1712807",
+    platform: "android",
+    domain: "www.dealnews.com",
+    bug: "1712807",
+    config: {
+      matches: ["*://www.dealnews.com/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1719859 - Add UA override for saxoinvestor.fr
+     * Webcompat issue #74678 - https://webcompat.com/issues/74678
+     *
+     * The site blocks Firefox with a server-side UA sniffer. Appending a
+     * Chrome version segment to the UA makes it work.
+     */
+    id: "bug1719859",
+    platform: "all",
+    domain: "saxoinvestor.fr",
+    bug: "1719859",
+    config: {
+      matches: ["*://*.saxoinvestor.fr/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome/91.0.4472.114";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1722954 - Add UA override for game.granbluefantasy.jp
+     * Webcompat issue #34310 - https://github.com/webcompat/web-bugs/issues/34310
+     *
+     * The website is sending a version of the site which is too small. Adding a partial
+     * safari iOS version of the UA sends us the right layout.
+     */
+    id: "bug1722954",
+    platform: "android",
+    domain: "granbluefantasy.jp",
+    bug: "1722954",
+    config: {
+      matches: ["*://*.granbluefantasy.jp/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " iPhone OS 12_0 like Mac OS X";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1738317 - Add UA override for vmos.cn
+     * Webcompat issue #90432 - https://github.com/webcompat/web-bugs/issues/90432
+     *
+     * Firefox for Android receives a desktop-only layout based on server-side
+     * UA sniffing. Spoofing as Chrome works fine.
+     */
+    id: "bug1738317",
+    platform: "android",
+    domain: "vmos.cn",
+    bug: "1738317",
+    config: {
+      matches: ["*://*.vmos.cn/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1743627 - Add UA override for renaud-bray.com
+     * Webcompat issue #55276 - https://github.com/webcompat/web-bugs/issues/55276
+     *
+     * Firefox for Android depends on "Version/" being there in the UA string,
+     * or it'll throw a runtime error.
+     */
+    id: "bug1743627",
+    platform: "android",
+    domain: "renaud-bray.com",
+    bug: "1743627",
+    config: {
+      matches: ["*://*.renaud-bray.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Version/0";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1743751 - Add UA override for slrclub.com
+     * Webcompat issue #91373 - https://github.com/webcompat/web-bugs/issues/91373
+     *
+     * On Firefox Android, the browser is receiving the desktop layout.
+     * Spoofing as Chrome works fine.
+     */
+    id: "bug1743751",
+    platform: "android",
+    domain: "slrclub.com",
+    bug: "1743751",
+    config: {
+      matches: ["*://*.slrclub.com/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1743754 - Add UA override for slrclub.com
+     * Webcompat issue #86839 - https://github.com/webcompat/web-bugs/issues/86839
+     *
+     * On Firefox Android, the browser is failing a UA parsing on Firefox UA.
+     */
+    id: "bug1743754",
+    platform: "android",
+    domain: "workflow.base.vn",
+    bug: "1743754",
+    config: {
+      matches: ["*://workflow.base.vn/*"],
+      uaTransformer: () => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1743429 - Add UA override for sites broken with the Version 100 User Agent
+     *
+     * Some sites have issues with a UA string with Firefox version 100 or higher,
+     * so present as version 99 for now.
+     */
+    id: "bug1743429",
+    platform: "all",
+    domain: "Sites with known Version 100 User Agent breakage",
+    bug: "1743429",
+    config: {
+      matches: [
+        "*://411.ca/", // #121332
+        "*://*.commerzbank.de/*", // Bug 1767630
+        "*://*.mms.telekom.de/*", // #1800241
+        "*://ubank.com.au/*", // #104099
+        "*://wifi.sncf/*", // #100194
+      ],
+      uaTransformer: originalUA => {
+        return UAHelpers.capVersionTo99(originalUA);
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1753461 - UA override for serieson.naver.com
+     * Webcompat issue #99993 - https://webcompat.com/issues/97298
+     *
+     * The site locks out Firefox users unless a Chrome UA is given,
+     * and locks out Linux users as well (so we use Windows+Chrome).
+     */
+    id: "bug1753461",
+    platform: "desktop",
+    domain: "serieson.naver.com",
+    bug: "1753461",
+    config: {
+      matches: ["*://serieson.naver.com/*"],
+      uaTransformer: originalUA => {
+        return "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.99 Safari/537.36";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1756872 - UA override for www.dolcegabbana.com
+     * Webcompat issue #99993 - https://webcompat.com/issues/99993
+     *
+     * The site's layout is broken on Firefox for Android
+     * without a full Chrome user-agent string.
+     */
+    id: "bug1756872",
+    platform: "android",
+    domain: "www.dolcegabbana.com",
+    bug: "1756872",
+    config: {
+      matches: ["*://www.dolcegabbana.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1771200 - UA override for animalplanet.com
+     * Webcompat issue #99993 - https://webcompat.com/issues/103727
+     *
+     * The videos are not playing and an error message is displayed
+     * in Firefox for Android, but work with Chrome UA
+     */
+    id: "bug1771200",
+    platform: "android",
+    domain: "animalplanet.com",
+    bug: "1771200",
+    config: {
+      matches: ["*://*.animalplanet.com/video/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1771200 - UA override for lazada.co.id
+     * Webcompat issue #106229 - https://webcompat.com/issues/106229
+     *
+     * The map is not playing and an error message is displayed
+     * in Firefox for Android, but work with Chrome UA
+     */
+    id: "bug1779059",
+    platform: "android",
+    domain: "lazada.co.id",
+    bug: "1779059",
+    config: {
+      matches: ["*://member-m.lazada.co.id/address/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1778168 - UA override for watch.antennaplus.gr
+     * Webcompat issue #106529 - https://webcompat.com/issues/106529
+     *
+     * The site's content is not loaded unless a Chrome UA is used,
+     * and breaks on Linux (so we claim Windows instead in that case).
+     */
+    id: "bug1778168",
+    platform: "desktop",
+    domain: "watch.antennaplus.gr",
+    bug: "1778168",
+    config: {
+      matches: ["*://watch.antennaplus.gr/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA({
+          desktopOS: "nonLinux",
+        });
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1776897 - UA override for www.edencast.fr
+     * Webcompat issue #106545 - https://webcompat.com/issues/106545
+     *
+     * The site's podcast audio player does not load unless a Chrome UA is used.
+     */
+    id: "bug1776897",
+    platform: "all",
+    domain: "www.edencast.fr",
+    bug: "1776897",
+    config: {
+      matches: ["*://www.edencast.fr/zoomcast*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1784361 - UA override for coldwellbankerhomes.com
+     * Webcompat issue #108535 - https://webcompat.com/issues/108535
+     *
+     * An error is thrown due to missing element, unless Chrome UA is used
+     */
+    id: "bug1784361",
+    platform: "android",
+    domain: "coldwellbankerhomes.com",
+    bug: "1784361",
+    config: {
+      matches: ["*://*.coldwellbankerhomes.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1786404 - UA override for business.help.royalmail.com
+     * Webcompat issue #109070 - https://webcompat.com/issues/109070
+     *
+     * Replacing `Firefox` with `FireFox` to evade one of their UA tests...
+     */
+    id: "bug1786404",
+    platform: "all",
+    domain: "business.help.royalmail.com",
+    bug: "1786404",
+    config: {
+      matches: ["*://business.help.royalmail.com/app/webforms/*"],
+      uaTransformer: originalUA => {
+        return originalUA.replace("Firefox", "FireFox");
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1790698 - UA override for wolf777.com
+     * Webcompat issue #103981 - https://webcompat.com/issues/103981
+     *
+     * Add 'Linux; ' next to the Android version or the site breaks
+     */
+    id: "bug1790698",
+    platform: "android",
+    domain: "wolf777.com",
+    bug: "1790698",
+    config: {
+      matches: ["*://wolf777.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA.replace("Android", "Linux; Android");
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1800936 - UA override for cov19ent.kdca.go.kr
+     * Webcompat issue #110655 - https://webcompat.com/issues/110655
+     *
+     * Add 'Chrome;' to the UA for the site to load styles
+     */
+    id: "bug1800936",
+    platform: "all",
+    domain: "cov19ent.kdca.go.kr",
+    bug: "1800936",
+    config: {
+      matches: ["*://cov19ent.kdca.go.kr/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1803131 - UA override for argaam.com
+     * Webcompat issue #113638 - https://webcompat.com/issues/113638
+     *
+     * To receive the proper mobile version instead of the desktop version
+     * the UA is spoofed.
+     */
+    id: "bug1803131",
+    platform: "android",
+    domain: "argaam.com",
+    bug: "1803131",
+    config: {
+      matches: ["*://*.argaam.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1819702 - UA override for feelgoodcontacts.com
+     * Webcompat issue #118030 - https://webcompat.com/issues/118030
+     *
+     * Spoof the UA to receive the mobile version instead
+     * of the broken desktop version for Android.
+     */
+    id: "bug1819702",
+    platform: "android",
+    domain: "feelgoodcontacts.com",
+    bug: "1819702",
+    config: {
+      matches: ["*://*.feelgoodcontacts.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1823966 - UA override for elearning.dmv.ca.gov
+     * Original report: https://bugzilla.mozilla.org/show_bug.cgi?id=1823785
+     */
+    id: "bug1823966",
+    platform: "all",
+    domain: "elearning.dmv.ca.gov",
+    bug: "1823966",
+    config: {
+      matches: ["*://*.elearning.dmv.ca.gov/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for admissions.nid.edu
+     * Webcompat issue #65753 - https://webcompat.com/issues/65753
+     */
+    id: "bug1827678-webc65753",
+    platform: "all",
+    domain: "admissions.nid.edu",
+    bug: "1827678",
+    config: {
+      matches: ["*://*.admissions.nid.edu/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for www.hepsiburada.com
+     * Webcompat issue #66888 - https://webcompat.com/issues/66888
+     */
+    id: "bug1827678-webc66888",
+    platform: "android",
+    domain: "www.hepsiburada.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://www.hepsiburada.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for bankmandiri.co.id
+     * Webcompat issue #67924 - https://webcompat.com/issues/67924
+     */
+    id: "bug1827678-webc67924",
+    platform: "android",
+    domain: "bankmandiri.co.id",
+    bug: "1827678",
+    config: {
+      matches: ["*://*.bankmandiri.co.id/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for frankfred.com
+     * Webcompat issue #68007 - https://webcompat.com/issues/68007
+     */
+    id: "bug1827678-webc68007",
+    platform: "android",
+    domain: "frankfred.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://*.frankfred.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for static.slots.lv
+     * Webcompat issue #68379 - https://webcompat.com/issues/68379
+     */
+    id: "bug1827678-webc68379",
+    platform: "android",
+    domain: "static.slots.lv",
+    bug: "1827678",
+    config: {
+      matches: ["*://static.slots.lv/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for mobile.onvue.com
+     * Webcompat issue #68520 - https://webcompat.com/issues/68520
+     */
+    id: "bug1827678-webc68520",
+    platform: "android",
+    domain: "mobile.onvue.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://mobile.onvue.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for avizia.com
+     * Webcompat issue #68635 - https://webcompat.com/issues/68635
+     */
+    id: "bug1827678-webc68635",
+    platform: "all",
+    domain: "avizia.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://*.avizia.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for www.yourtexasbenefits.com
+     * Webcompat issue #76785 - https://webcompat.com/issues/76785
+     */
+    id: "bug1827678-webc76785",
+    platform: "android",
+    domain: "www.yourtexasbenefits.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://www.yourtexasbenefits.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for www.free4talk.com
+     * Webcompat issue #77727 - https://webcompat.com/issues/77727
+     */
+    id: "bug1827678-webc77727",
+    platform: "android",
+    domain: "www.free4talk.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://www.free4talk.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for watch.indee.tv
+     * Webcompat issue #77912 - https://webcompat.com/issues/77912
+     */
+    id: "bug1827678-webc77912",
+    platform: "all",
+    domain: "watch.indee.tv",
+    bug: "1827678",
+    config: {
+      matches: ["*://watch.indee.tv/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for viewer-ebook.books.com.tw
+     * Webcompat issue #80180 - https://webcompat.com/issues/80180
+     */
+    id: "bug1827678-webc80180",
+    platform: "all",
+    domain: "viewer-ebook.books.com.tw",
+    bug: "1827678",
+    config: {
+      matches: ["*://viewer-ebook.books.com.tw/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for jelly.jd.com
+     * Webcompat issue #83269 - https://webcompat.com/issues/83269
+     */
+    id: "bug1827678-webc83269",
+    platform: "android",
+    domain: "jelly.jd.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://jelly.jd.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for f2bbs.com
+     * Webcompat issue #84932 - https://webcompat.com/issues/84932
+     */
+    id: "bug1827678-webc84932",
+    platform: "android",
+    domain: "f2bbs.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://f2bbs.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for kt.com
+     * Webcompat issue #119012 - https://webcompat.com/issues/119012
+     */
+    id: "bug1827678-webc119012",
+    platform: "all",
+    domain: "kt.com",
+    bug: "1827678",
+    config: {
+      matches: ["*://*.kt.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for oirsa.org
+     * Webcompat issue #119402 - https://webcompat.com/issues/119402
+     */
+    id: "bug1827678-webc119402",
+    platform: "all",
+    domain: "oirsa.org",
+    bug: "1827678",
+    config: {
+      matches: ["*://*.oirsa.org/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for sistema.ibglbrasil.com.br
+     * Webcompat issue #119785 - https://webcompat.com/issues/119785
+     */
+    id: "bug1827678-webc119785",
+    platform: "all",
+    domain: "sistema.ibglbrasil.com.br",
+    bug: "1827678",
+    config: {
+      matches: ["*://sistema.ibglbrasil.com.br/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1827678 - UA override for onp.cloud.waterloo.ca
+     * Webcompat issue #120450 - https://webcompat.com/issues/120450
+     */
+    id: "bug1827678-webc120450",
+    platform: "all",
+    domain: "onp.cloud.waterloo.ca",
+    bug: "1827678",
+    config: {
+      matches: ["*://onp.cloud.waterloo.ca/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1830739 - UA override for casino sites
+     *
+     * The sites are showing unsupported message with the same UI
+     */
+    id: "bug1830739",
+    platform: "android",
+    domain: "casino sites",
+    bug: "1830739",
+    config: {
+      matches: [
+        "*://*.captainjackcasino.com/*", // 79490
+        "*://*.casinoextreme.eu/*", // 118175
+        "*://*.cryptoloko.com/*", // 117911
+        "*://*.heapsowins.com/*", // 120027
+        "*://*.planet7casino.com/*", // 120609
+        "*://*.yebocasino.co.za/*", // 88409
+      ],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1830821 - UA override for m.tworld.co.kr
+     * Webcompat issue #118998 - https://webcompat.com/issues/118998
+     */
+    id: "bug1830821-webc118998",
+    platform: "android",
+    domain: "m.tworld.co.kr",
+    bug: "1830821",
+    config: {
+      matches: ["*://m.tworld.co.kr/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1830821 - UA override for webcartop.jp
+     * Webcompat issue #113663 - https://webcompat.com/issues/113663
+     */
+    id: "bug1830821-webc113663",
+    platform: "android",
+    domain: "webcartop.jp",
+    bug: "1830821",
+    config: {
+      matches: ["*://*.webcartop.jp/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1830821 - UA override for enjoy.point.auone.jp
+     * Webcompat issue #90981 - https://webcompat.com/issues/90981
+     */
+    id: "bug1830821-webc90981",
+    platform: "android",
+    domain: "enjoy.point.auone.jp",
+    bug: "1830821",
+    config: {
+      matches: ["*://enjoy.point.auone.jp/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1751604 - UA override for /www.otsuka.co.jp/fib/
+     *
+     * The site's content is not loaded on mobile unless a Chrome UA is used.
+     */
+    id: "bug1829126",
+    platform: "android",
+    domain: "www.otsuka.co.jp",
+    bug: "1829126",
+    config: {
+      matches: ["*://www.otsuka.co.jp/fib/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1831441 - UA override for luna.amazon.com
+     *
+     * Games are unplayable unless a Chrome UA is used.
+     */
+    id: "bug1831441",
+    platform: "all",
+    domain: "luna.amazon.com",
+    bug: "1831441",
+    config: {
+      matches: ["*://luna.amazon.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836109 - UA override for watch.tonton.com.my
+     *
+     * The site's content is not loaded unless a Chrome UA is used.
+     */
+    id: "bug1836109",
+    platform: "all",
+    domain: "watch.tonton.com.my",
+    bug: "1836109",
+    config: {
+      matches: ["*://watch.tonton.com.my/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836112 - UA override for www.capcut.cn
+     *
+     * The site's content is not loaded unless a Chrome UA is used.
+     */
+    id: "bug1836112",
+    platform: "all",
+    domain: "www.capcut.cn",
+    bug: "1836112",
+    config: {
+      matches: ["*://www.capcut.cn/editor*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836116 - UA override for www.slushy.com
+     *
+     * The site's content is not loaded without a Chrome UA spoof.
+     */
+    id: "bug1836116",
+    platform: "all",
+    domain: "www.slushy.com",
+    bug: "1836116",
+    config: {
+      matches: ["*://www.slushy.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome/113.0.0.0";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836135 - UA override for gts-pro.sdimedia.com
+     *
+     * The site's content is not loaded without a Chrome UA spoof.
+     */
+    id: "bug1836135",
+    platform: "all",
+    domain: "gts-pro.sdimedia.com",
+    bug: "1836135",
+    config: {
+      matches: ["*://gts-pro.sdimedia.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA.replace("Firefox/", "Fx/") + " Chrome/113.0.0.0";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836140 - UA override for indices.iriworldwide.com
+     *
+     * The site's content is not loaded without a UA spoof.
+     */
+    id: "bug1836140",
+    platform: "all",
+    domain: "indices.iriworldwide.com",
+    bug: "1836140",
+    config: {
+      matches: ["*://indices.iriworldwide.com/covid19/*"],
+      uaTransformer: originalUA => {
+        return originalUA.replace("Firefox/", "Fx/");
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836178 - UA override for atracker.pro
+     *
+     * The site's content is not loaded without a Chrome UA spoof.
+     */
+    id: "bug1836178",
+    platform: "all",
+    domain: "atracker.pro",
+    bug: "1836178",
+    config: {
+      matches: ["*://atracker.pro/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome/113.0.0.0";
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836181 - UA override for conference.amwell.com
+     *
+     * The site's content is not loaded unless a Chrome UA is used.
+     */
+    id: "bug1836181",
+    platform: "all",
+    domain: "conference.amwell.com",
+    bug: "1836181",
+    config: {
+      matches: ["*://conference.amwell.com/*"],
+      uaTransformer: originalUA => {
+        return UAHelpers.getDeviceAppropriateChromeUA();
+      },
+    },
+  },
+  {
+    /*
+     * Bug 1836182 - UA override for www.flatsatshadowglen.com
+     *
+     * The site's content is not loaded without a Chrome UA spoof.
+     */
+    id: "bug1836182",
+    platform: "all",
+    domain: "www.flatsatshadowglen.com",
+    bug: "1836182",
+    config: {
+      matches: ["*://www.flatsatshadowglen.com/*"],
+      uaTransformer: originalUA => {
+        return originalUA + " Chrome/113.0.0.0";
+      },
+    },
+  },
+];
+
+module.exports = AVAILABLE_UA_OVERRIDES;
diff --git a/browser/extensions/webcompat/experiment-apis/aboutConfigPrefs.js b/browser/extensions/webcompat/experiment-apis/aboutConfigPrefs.js
new file mode 100644
index 0000000000..21ad297dc1
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/aboutConfigPrefs.js
@@ -0,0 +1,53 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global ExtensionAPI, ExtensionCommon, Services, XPCOMUtils */
+
+this.aboutConfigPrefs = class extends ExtensionAPI {
+  getAPI(context) {
+    const EventManager = ExtensionCommon.EventManager;
+    const extensionIDBase = context.extension.id.split("@")[0];
+    const extensionPrefNameBase = `extensions.${extensionIDBase}.`;
+
+    return {
+      aboutConfigPrefs: {
+        onPrefChange: new EventManager({
+          context,
+          name: "aboutConfigPrefs.onUAOverridesPrefChange",
+          register: (fire, name) => {
+            const prefName = `${extensionPrefNameBase}${name}`;
+            const callback = () => {
+              fire.async(name).catch(() => {}); // ignore Message Manager disconnects
+            };
+            Services.prefs.addObserver(prefName, callback);
+            return () => {
+              Services.prefs.removeObserver(prefName, callback);
+            };
+          },
+        }).api(),
+        async getBranch(branchName) {
+          const branch = `${extensionPrefNameBase}${branchName}.`;
+          return Services.prefs.getChildList(branch).map(pref => {
+            const name = pref.replace(branch, "");
+            return { name, value: Services.prefs.getBoolPref(pref) };
+          });
+        },
+        async getPref(name) {
+          try {
+            return Services.prefs.getBoolPref(
+              `${extensionPrefNameBase}${name}`
+            );
+          } catch (_) {
+            return undefined;
+          }
+        },
+        async setPref(name, value) {
+          Services.prefs.setBoolPref(`${extensionPrefNameBase}${name}`, value);
+        },
+      },
+    };
+  }
+};
diff --git a/browser/extensions/webcompat/experiment-apis/aboutConfigPrefs.json b/browser/extensions/webcompat/experiment-apis/aboutConfigPrefs.json
new file mode 100644
index 0000000000..44284f199c
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/aboutConfigPrefs.json
@@ -0,0 +1,72 @@
+[
+  {
+    "namespace": "aboutConfigPrefs",
+    "description": "experimental API extension to allow access to about:config preferences",
+    "events": [
+      {
+        "name": "onPrefChange",
+        "type": "function",
+        "parameters": [
+          {
+            "name": "name",
+            "type": "string",
+            "description": "The preference which changed"
+          }
+        ],
+        "extraParameters": [
+          {
+            "name": "name",
+            "type": "string",
+            "description": "The preference to monitor"
+          }
+        ]
+      }
+    ],
+    "functions": [
+      {
+        "name": "getBranch",
+        "type": "function",
+        "description": "Get all child prefs for a branch",
+        "parameters": [
+          {
+            "name": "branchName",
+            "type": "string",
+            "description": "The branch name"
+          }
+        ],
+        "async": true
+      },
+      {
+        "name": "getPref",
+        "type": "function",
+        "description": "Get a preference's value",
+        "parameters": [
+          {
+            "name": "name",
+            "type": "string",
+            "description": "The preference name"
+          }
+        ],
+        "async": true
+      },
+      {
+        "name": "setPref",
+        "type": "function",
+        "description": "Set a preference's value",
+        "parameters": [
+          {
+            "name": "name",
+            "type": "string",
+            "description": "The preference name"
+          },
+          {
+            "name": "value",
+            "type": "boolean",
+            "description": "The new value"
+          }
+        ],
+        "async": true
+      }
+    ]
+  }
+]
diff --git a/browser/extensions/webcompat/experiment-apis/appConstants.js b/browser/extensions/webcompat/experiment-apis/appConstants.js
new file mode 100644
index 0000000000..2869f299a4
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/appConstants.js
@@ -0,0 +1,28 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global AppConstants, ExtensionAPI, XPCOMUtils */
+
+this.appConstants = class extends ExtensionAPI {
+  getAPI(context) {
+    return {
+      appConstants: {
+        getReleaseBranch: () => {
+          if (AppConstants.NIGHTLY_BUILD) {
+            return "nightly";
+          } else if (AppConstants.MOZ_DEV_EDITION) {
+            return "dev_edition";
+          } else if (AppConstants.EARLY_BETA_OR_EARLIER) {
+            return "early_beta_or_earlier";
+          } else if (AppConstants.RELEASE_OR_BETA) {
+            return "release_or_beta";
+          }
+          return "unknown";
+        },
+      },
+    };
+  }
+};
diff --git a/browser/extensions/webcompat/experiment-apis/appConstants.json b/browser/extensions/webcompat/experiment-apis/appConstants.json
new file mode 100644
index 0000000000..cf04915eca
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/appConstants.json
@@ -0,0 +1,15 @@
+[
+  {
+    "namespace": "appConstants",
+    "description": "experimental API to expose some app constants",
+    "functions": [
+      {
+        "name": "getReleaseBranch",
+        "type": "function",
+        "description": "",
+        "async": true,
+        "parameters": []
+      }
+    ]
+  }
+]
diff --git a/browser/extensions/webcompat/experiment-apis/matchPatterns.js b/browser/extensions/webcompat/experiment-apis/matchPatterns.js
new file mode 100644
index 0000000000..422cba5fc4
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/matchPatterns.js
@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global ExtensionAPI */
+
+this.matchPatterns = class extends ExtensionAPI {
+  getAPI(context) {
+    return {
+      matchPatterns: {
+        getMatcher(patterns) {
+          const set = new MatchPatternSet(patterns);
+          return Cu.cloneInto(
+            {
+              matches: url => {
+                return set.matches(url);
+              },
+            },
+            context.cloneScope,
+            {
+              cloneFunctions: true,
+            }
+          );
+        },
+      },
+    };
+  }
+};
diff --git a/browser/extensions/webcompat/experiment-apis/matchPatterns.json b/browser/extensions/webcompat/experiment-apis/matchPatterns.json
new file mode 100644
index 0000000000..6fb4dc10fc
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/matchPatterns.json
@@ -0,0 +1,29 @@
+[
+  {
+    "namespace": "matchPatterns",
+    "description": "experimental API extension to expose MatchPattern functionality",
+    "functions": [
+      {
+        "name": "getMatcher",
+        "type": "function",
+        "description": "get a MatchPatternSet",
+        "parameters": [
+          {
+            "name": "patterns",
+            "description": "Array of string URL patterns to match",
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          }
+        ],
+        "returns": {
+          "type": "object",
+          "properties": {
+            "matches": { "type": "function" }
+          }
+        }
+      }
+    ]
+  }
+]
diff --git a/browser/extensions/webcompat/experiment-apis/systemManufacturer.js b/browser/extensions/webcompat/experiment-apis/systemManufacturer.js
new file mode 100644
index 0000000000..b7dc68415c
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/systemManufacturer.js
@@ -0,0 +1,23 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global ExtensionAPI, Services, XPCOMUtils */
+
+this.systemManufacturer = class extends ExtensionAPI {
+  getAPI(context) {
+    return {
+      systemManufacturer: {
+        getManufacturer() {
+          try {
+            return Services.sysinfo.getProperty("manufacturer");
+          } catch (_) {
+            return undefined;
+          }
+        },
+      },
+    };
+  }
+};
diff --git a/browser/extensions/webcompat/experiment-apis/systemManufacturer.json b/browser/extensions/webcompat/experiment-apis/systemManufacturer.json
new file mode 100644
index 0000000000..c64fccc46d
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/systemManufacturer.json
@@ -0,0 +1,20 @@
+[
+  {
+    "namespace": "systemManufacturer",
+    "description": "experimental API extension to allow reading the device's manufacturer",
+    "functions": [
+      {
+        "name": "getManufacturer",
+        "type": "function",
+        "description": "Get the device's manufacturer",
+        "parameters": [],
+        "returns": {
+          "type": "string",
+          "properties": {},
+          "additionalProperties": { "type": "any" },
+          "description": "The manufacturer's name."
+        }
+      }
+    ]
+  }
+]
diff --git a/browser/extensions/webcompat/experiment-apis/trackingProtection.js b/browser/extensions/webcompat/experiment-apis/trackingProtection.js
new file mode 100644
index 0000000000..0f5d9a4233
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/trackingProtection.js
@@ -0,0 +1,216 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global ExtensionAPI, ExtensionCommon, ExtensionParent, Services, XPCOMUtils */
+
+// eslint-disable-next-line mozilla/reject-importGlobalProperties
+XPCOMUtils.defineLazyGlobalGetters(this, ["URL", "ChannelWrapper"]);
+
+class AllowList {
+  constructor(id) {
+    this._id = id;
+  }
+
+  setShims(patterns, notHosts) {
+    this._shimPatterns = patterns;
+    this._shimMatcher = new MatchPatternSet(patterns || []);
+    this._shimNotHosts = notHosts || [];
+    return this;
+  }
+
+  setAllows(patterns, hosts) {
+    this._allowPatterns = patterns;
+    this._allowMatcher = new MatchPatternSet(patterns || []);
+    this._allowHosts = hosts || [];
+    return this;
+  }
+
+  shims(url, topHost) {
+    return (
+      this._shimMatcher?.matches(url) && !this._shimNotHosts?.includes(topHost)
+    );
+  }
+
+  allows(url, topHost) {
+    return (
+      this._allowMatcher?.matches(url) && this._allowHosts?.includes(topHost)
+    );
+  }
+}
+
+class Manager {
+  constructor() {
+    this._allowLists = new Map();
+  }
+
+  _getAllowList(id) {
+    if (!this._allowLists.has(id)) {
+      this._allowLists.set(id, new AllowList(id));
+    }
+    return this._allowLists.get(id);
+  }
+
+  _ensureStarted() {
+    if (this._classifierObserver) {
+      return;
+    }
+
+    this._unblockedChannelIds = new Set();
+    this._channelClassifier = Cc[
+      "@mozilla.org/url-classifier/channel-classifier-service;1"
+    ].getService(Ci.nsIChannelClassifierService);
+    this._classifierObserver = {};
+    this._classifierObserver.observe = (subject, topic, data) => {
+      switch (topic) {
+        case "http-on-stop-request": {
+          const { channelId } = subject.QueryInterface(Ci.nsIIdentChannel);
+          this._unblockedChannelIds.delete(channelId);
+          break;
+        }
+        case "urlclassifier-before-block-channel": {
+          const channel = subject.QueryInterface(
+            Ci.nsIUrlClassifierBlockedChannel
+          );
+          const { channelId, url } = channel;
+          let topHost;
+          try {
+            topHost = new URL(channel.topLevelUrl).hostname;
+          } catch (_) {
+            return;
+          }
+          // If anti-tracking webcompat is disabled, we only permit replacing
+          // channels, not fully unblocking them.
+          if (Manager.ENABLE_WEBCOMPAT) {
+            // if any allowlist unblocks the request entirely, we allow it
+            for (const allowList of this._allowLists.values()) {
+              if (allowList.allows(url, topHost)) {
+                this._unblockedChannelIds.add(channelId);
+                channel.allow();
+                return;
+              }
+            }
+          }
+          // otherwise, if any allowlist shims the request we say it's replaced
+          for (const allowList of this._allowLists.values()) {
+            if (allowList.shims(url, topHost)) {
+              this._unblockedChannelIds.add(channelId);
+              channel.replace();
+              return;
+            }
+          }
+          break;
+        }
+      }
+    };
+    Services.obs.addObserver(this._classifierObserver, "http-on-stop-request");
+    this._channelClassifier.addListener(this._classifierObserver);
+  }
+
+  stop() {
+    if (!this._classifierObserver) {
+      return;
+    }
+
+    Services.obs.removeObserver(
+      this._classifierObserver,
+      "http-on-stop-request"
+    );
+    this._channelClassifier.removeListener(this._classifierObserver);
+    delete this._channelClassifier;
+    delete this._classifierObserver;
+  }
+
+  wasChannelIdUnblocked(channelId) {
+    return this._unblockedChannelIds?.has(channelId);
+  }
+
+  allow(allowListId, patterns, hosts) {
+    this._ensureStarted();
+    this._getAllowList(allowListId).setAllows(patterns, hosts);
+  }
+
+  shim(allowListId, patterns, notHosts) {
+    this._ensureStarted();
+    this._getAllowList(allowListId).setShims(patterns, notHosts);
+  }
+
+  revoke(allowListId) {
+    this._allowLists.delete(allowListId);
+  }
+}
+var manager = new Manager();
+
+function getChannelId(context, requestId) {
+  const wrapper = ChannelWrapper.getRegisteredChannel(
+    requestId,
+    context.extension.policy,
+    context.xulBrowser.frameLoader.remoteTab
+  );
+  return wrapper?.channel?.QueryInterface(Ci.nsIIdentChannel)?.channelId;
+}
+
+var dFPIPrefName = "network.cookie.cookieBehavior";
+var dFPIPbPrefName = "network.cookie.cookieBehavior.pbmode";
+var dFPIStatus;
+function updateDFPIStatus() {
+  dFPIStatus = {
+    nonPbMode: 5 == Services.prefs.getIntPref(dFPIPrefName),
+    pbMode: 5 == Services.prefs.getIntPref(dFPIPbPrefName),
+  };
+}
+
+this.trackingProtection = class extends ExtensionAPI {
+  onShutdown(isAppShutdown) {
+    if (manager) {
+      manager.stop();
+    }
+    Services.prefs.removeObserver(dFPIPrefName, updateDFPIStatus);
+    Services.prefs.removeObserver(dFPIPbPrefName, updateDFPIStatus);
+  }
+
+  getAPI(context) {
+    Services.prefs.addObserver(dFPIPrefName, updateDFPIStatus);
+    Services.prefs.addObserver(dFPIPbPrefName, updateDFPIStatus);
+    updateDFPIStatus();
+
+    return {
+      trackingProtection: {
+        async shim(allowListId, patterns, notHosts) {
+          manager.shim(allowListId, patterns, notHosts);
+        },
+        async allow(allowListId, patterns, hosts) {
+          manager.allow(allowListId, patterns, hosts);
+        },
+        async revoke(allowListId) {
+          manager.revoke(allowListId);
+        },
+        async wasRequestUnblocked(requestId) {
+          if (!manager) {
+            return false;
+          }
+          const channelId = getChannelId(context, requestId);
+          if (!channelId) {
+            return false;
+          }
+          return manager.wasChannelIdUnblocked(channelId);
+        },
+        async isDFPIActive(isPrivate) {
+          if (isPrivate) {
+            return dFPIStatus.pbMode;
+          }
+          return dFPIStatus.nonPbMode;
+        },
+      },
+    };
+  }
+};
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  Manager,
+  "ENABLE_WEBCOMPAT",
+  "privacy.antitracking.enableWebcompat",
+  false
+);
diff --git a/browser/extensions/webcompat/experiment-apis/trackingProtection.json b/browser/extensions/webcompat/experiment-apis/trackingProtection.json
new file mode 100644
index 0000000000..c495f39add
--- /dev/null
+++ b/browser/extensions/webcompat/experiment-apis/trackingProtection.json
@@ -0,0 +1,102 @@
+[
+  {
+    "namespace": "trackingProtection",
+    "description": "experimental API allow requests through ETP",
+    "functions": [
+      {
+        "name": "isDFPIActive",
+        "type": "function",
+        "description": "Returns whether dFPI is active for private/non-private browsing tabs",
+        "parameters": [
+          {
+            "type": "boolean",
+            "name": "isPrivate"
+          }
+        ],
+        "async": true
+      },
+      {
+        "name": "shim",
+        "type": "function",
+        "description": "Set specified URL patterns as intended to be shimmed",
+        "parameters": [
+          {
+            "name": "allowlistId",
+            "description": "Identfier for the allow-list, so it may be added-to or revoked",
+            "type": "string"
+          },
+          {
+            "name": "patterns",
+            "description": "Array of match patterns",
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          {
+            "name": "notHosts",
+            "description": "Hosts on which to not shim these patterns",
+            "type": "array",
+            "optional": true,
+            "items": {
+              "type": "string"
+            }
+          }
+        ]
+      },
+      {
+        "name": "allow",
+        "type": "function",
+        "description": "Set specified URL patterns as intended to be allowed through the content blocker for the specified top hosts",
+        "parameters": [
+          {
+            "name": "allowlistId",
+            "description": "Identfier for the allow-list, so it may be added-to or revoked",
+            "type": "string"
+          },
+          {
+            "name": "patterns",
+            "description": "Array of match patterns",
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          },
+          {
+            "name": "hosts",
+            "description": "Hosts to allow the patterns on",
+            "type": "array",
+            "items": {
+              "type": "string"
+            }
+          }
+        ],
+        "async": true
+      },
+      {
+        "name": "revoke",
+        "type": "function",
+        "description": "Revokes the given allow-list entirely (both shims and allows)",
+        "parameters": [
+          {
+            "name": "allowListId",
+            "type": "string"
+          }
+        ],
+        "async": true
+      },
+      {
+        "name": "wasRequestUnblocked",
+        "type": "function",
+        "description": "Whether the given requestId was unblocked by any allowList",
+        "parameters": [
+          {
+            "name": "requestId",
+            "type": "string"
+          }
+        ],
+        "async": true
+      }
+    ]
+  }
+]
diff --git a/browser/extensions/webcompat/injections/css/bug0000000-testbed-css-injection.css b/browser/extensions/webcompat/injections/css/bug0000000-testbed-css-injection.css
new file mode 100644
index 0000000000..566685c2da
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug0000000-testbed-css-injection.css
@@ -0,0 +1,7 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#css-injection.red {
+  background-color: #0f0;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1570328-developer-apple.com-transform-scale.css b/browser/extensions/webcompat/injections/css/bug1570328-developer-apple.com-transform-scale.css
new file mode 100644
index 0000000000..05f7e685b9
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1570328-developer-apple.com-transform-scale.css
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * developer.apple.com - content of the page is shifted to the left
+ * Bug #1570328 - https://bugzilla.mozilla.org/show_bug.cgi?id=1570328
+ * WebCompat issue #4070 - https://webcompat.com/issues/4070
+ *
+ * The site is relying on zoom property which is not supported by Mozilla,
+ * see https://bugzilla.mozilla.org/show_bug.cgi?id=390936. Adding a combination
+ * of transform: scale(1.4), transform-origin and width fixes the issue
+ */
+@media only screen and (min-device-width: 320px) and (max-device-width: 980px),
+  (min-device-width: 1024px) and (max-device-width: 1024px) and (min-device-height: 1366px) and (max-device-height: 1366px) and (min-width: 320px) and (max-width: 980px) {
+  #tocContainer {
+    transform-origin: 0 0;
+    transform: scale(1.4);
+    width: 71.4%;
+  }
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1575000-apply.lloydsbank.co.uk-radio-buttons-fix.css b/browser/extensions/webcompat/injections/css/bug1575000-apply.lloydsbank.co.uk-radio-buttons-fix.css
new file mode 100644
index 0000000000..e157dc6920
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1575000-apply.lloydsbank.co.uk-radio-buttons-fix.css
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * apply.lloydsbank.co.uk - radio buttons are misplaced
+ * Bug #1575000 - https://bugzilla.mozilla.org/show_bug.cgi?id=1575000
+ * WebCompat issue #34969 - https://webcompat.com/issues/34969
+ *
+ * Radio buttons are displaced to the left due to positioning issue of ::before
+ * pseudo element, adding position relative to it's parent fixes the issue.
+ */
+.radio-content-field .radio.inline label span.text {
+  position: relative;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1605611-maps.google.com-directions-time.css b/browser/extensions/webcompat/injections/css/bug1605611-maps.google.com-directions-time.css
new file mode 100644
index 0000000000..75ca4a8723
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1605611-maps.google.com-directions-time.css
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Bug 1605611 - Cannot change Departure/arrival dates in Google Maps on Android
+ *
+ * Google Maps hides a datetime-local in its directions picker by giving it
+ * z-index:-50000, which causes it to be unclickable in Firefox. Here we
+ * use opacity:0 instead to hide it, while letting it remain clickable.
+ */
+
+.ml-route-options-picker-container input[type="datetime-local"] {
+  z-index: unset;
+  opacity: 0;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1610344-directv.com.co-hide-unsupported-message.css b/browser/extensions/webcompat/injections/css/bug1610344-directv.com.co-hide-unsupported-message.css
new file mode 100644
index 0000000000..9f673bee95
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1610344-directv.com.co-hide-unsupported-message.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * directv.com.co - Browser is not supported message
+ * Bug #1610344 - https://bugzilla.mozilla.org/show_bug.cgi?id=1610344
+ * WebCompat issue #41822 - https://webcompat.com/issues/41822
+ *
+ * directv.com.co is showing a "This browser is not supported" message in
+ * Firefox. Our tests indicated that everything is working just fine, and our
+ * previous contact attempts have not been successful. This intervention
+ * hides the large red unsupported banner.
+ */
+.browser-compatible.compatible.incompatible {
+  display: none;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1644830-missingmail.usps.com-checkboxes-not-visible.css b/browser/extensions/webcompat/injections/css/bug1644830-missingmail.usps.com-checkboxes-not-visible.css
new file mode 100644
index 0000000000..fc1cb7489a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1644830-missingmail.usps.com-checkboxes-not-visible.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * missingmail.usps.com - Unable to mark the check-boxes from "Disclaimer and
+ * Terms and Conditions" section
+ * Bug #1644830 - https://bugzilla.mozilla.org/show_bug.cgi?id=1644830
+ * WebCompat issue #53950 - https://webcompat.com/issues/53950
+ *
+ * missingmail.usps.com runs into a case of bug 997189, where an absolutely
+ * positioned inline-block element with floating siblings is shifter to the
+ * right, and thus invisible.
+ */
+.mrc-custom-checkbox-container input {
+  margin-left: -3rem;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1651917-teletrader.com.body-transform-origin.css b/browser/extensions/webcompat/injections/css/bug1651917-teletrader.com.body-transform-origin.css
new file mode 100644
index 0000000000..2c4429a301
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1651917-teletrader.com.body-transform-origin.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * teletrader.com - content is shifted down and right
+ * Bug #1651917 - https://bugzilla.mozilla.org/show_bug.cgi?id=1651917
+ * WebCompat issue #55217 - https://webcompat.com/issues/55217
+ *
+ * The content is shifted down and right, because they use webkit prefixes
+ * for scaling and redefining the origin. Firefox doesn't support
+ *     -webkit-transform-origin-x/y
+ * This is the object of https://bugzilla.mozilla.org/show_bug.cgi?id=1584881
+ * Adding transform-origin: 0 0; to body fixes the issue
+ */
+body {
+  transform-origin: 0 0;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1653075-livescience.com-scrollbar-width.css b/browser/extensions/webcompat/injections/css/bug1653075-livescience.com-scrollbar-width.css
new file mode 100644
index 0000000000..ae14d1ec13
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1653075-livescience.com-scrollbar-width.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * livescience.com - a scrollbar covering navigation menu
+ * Bug #1653075 - https://bugzilla.mozilla.org/show_bug.cgi?id=1653075
+ *
+ * The scrollbar is covering navigation items and that makes them half hidden.
+ * There are some ::-webkit-scrollbar css rules applied to the scrollbar,
+ * making it thinner. Adding similar rules for Firefox fixes the issue.
+ */
+
+.trending__list {
+  scrollbar-width: thin;
+  scrollbar-color: #f9ae3b #f5f5f5;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1654877-preev.com-moz-appearance-fix.css b/browser/extensions/webcompat/injections/css/bug1654877-preev.com-moz-appearance-fix.css
new file mode 100644
index 0000000000..b13c3052f3
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1654877-preev.com-moz-appearance-fix.css
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * preev.com - typed numbers are not fully visible
+ * Bug #1654877 - https://bugzilla.mozilla.org/show_bug.cgi?id=1654877
+ * WebCompat issue #55099 - https://webcompat.com/issues/55099
+ *
+ * It's hard to see the entered number because the spin button is
+ * taking too much space. While there is -moz-appearance: textfield,
+ * -webkit-appearance: none; underneath supersedes it,
+ * leaving the spin button visible. Adding -moz-appearance: textfield;
+ * as a separate rule fixes the issue
+ */
+input[type="number"],
+input[type="text"] {
+  -moz-appearance: textfield;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1654907-reactine.ca-hide-unsupported.css b/browser/extensions/webcompat/injections/css/bug1654907-reactine.ca-hide-unsupported.css
new file mode 100644
index 0000000000..6cecb6658a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1654907-reactine.ca-hide-unsupported.css
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * reactine.ca - Unsupported browser message
+ * Bug #1654907 - https://bugzilla.mozilla.org/show_bug.cgi?id=1654907
+ * WebCompat issue #55481 - https://webcompat.com/issues/55481
+ *
+ * reactine.ca is showing "Sorry this browser is not supported."
+ * message if Firefox for Android based on UA detection. Site seems
+ * to be working fine, so this intervention is to hide this message
+ */
+#browser-alert {
+  display: none !important;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1694470-myvidster.com-content-not-shown.css b/browser/extensions/webcompat/injections/css/bug1694470-myvidster.com-content-not-shown.css
new file mode 100644
index 0000000000..adec7101ba
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1694470-myvidster.com-content-not-shown.css
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * m.myvidster.com - Content is not shown
+ * Bug #1694470 - https://bugzilla.mozilla.org/show_bug.cgi?id=1694470
+ * WebCompat issue #67308 - https://webcompat.com/issues/67308
+ *
+ * The site depends on Sencha Touch and should receive some specific
+ * -webkit-box-flex be working.
+ */
+#home_refresh_var {
+  -webkit-box-flex: 1;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1707795-office365-sheets-overscroll-disable.css b/browser/extensions/webcompat/injections/css/bug1707795-office365-sheets-overscroll-disable.css
new file mode 100644
index 0000000000..7165ceb70f
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1707795-office365-sheets-overscroll-disable.css
@@ -0,0 +1,12 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * www.office.com - There is an overscroll effect on Excel sheets which is
+ * not a very pleasant user experience. This invention disables it.
+ */
+
+.ewr-sheetcontainer {
+  overscroll-behavior: none;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1712833-buskocchi.desuca.co.jp-fix-map-height.css b/browser/extensions/webcompat/injections/css/bug1712833-buskocchi.desuca.co.jp-fix-map-height.css
new file mode 100644
index 0000000000..b4b8ca4a34
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1712833-buskocchi.desuca.co.jp-fix-map-height.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * buskocchi.desuca.co.jp - Ensure that the map has a height so it is visible.
+ * Bug #1712833 - https://bugzilla.mozilla.org/show_bug.cgi?id=1712833
+ * WebCompat issue #50837 - https://webcompat.com/issues/50837
+ */
+
+form[name="main"] {
+  height: 100%;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1741234-patient.alphalabs.ca-height-fix.css b/browser/extensions/webcompat/injections/css/bug1741234-patient.alphalabs.ca-height-fix.css
new file mode 100644
index 0000000000..3765d1de1e
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1741234-patient.alphalabs.ca-height-fix.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * patient.alphalabs.ca - "Continue" button is overlapped by displaced page footer
+ * Bug #1741234 - https://bugzilla.mozilla.org/show_bug.cgi?id=1741234
+ * WebCompat issue #93156 - https://webcompat.com/issues/93156
+ */
+
+body {
+  height: 100%;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1765947-veniceincoming.com-left-fix.css b/browser/extensions/webcompat/injections/css/bug1765947-veniceincoming.com-left-fix.css
new file mode 100644
index 0000000000..8c1ab7b2ae
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1765947-veniceincoming.com-left-fix.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * veniceincoming.com - site is not usable
+ * Bug #1765947 - https://bugzilla.mozilla.org/show_bug.cgi?id=1765947
+ * WebCompat issue #102133 - https://webcompat.com/issues/102133
+ */
+
+.tour-list .single-tour .mobile-link {
+  left: 0;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1770962-coldwellbankerhomes.com-image-height.css b/browser/extensions/webcompat/injections/css/bug1770962-coldwellbankerhomes.com-image-height.css
new file mode 100644
index 0000000000..f9460951af
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1770962-coldwellbankerhomes.com-image-height.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * coldwellbankerhomes.com - Property images are displayed squeezed
+ * Bug #1770962 - https://bugzilla.mozilla.org/show_bug.cgi?id=1770962
+ * WebCompat issue #102872 - https://webcompat.com/issues/102872
+ */
+
+.property-snapshot-psr-panel
+  .prop-pix
+  .photo-carousel.owl
+  .owl-stage-outer
+  .owl-item
+  img {
+  height: -moz-available;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1774490-rainews.it-gallery-fix.css b/browser/extensions/webcompat/injections/css/bug1774490-rainews.it-gallery-fix.css
new file mode 100644
index 0000000000..840e4ad7fb
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1774490-rainews.it-gallery-fix.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * rainews.it - Image slideshow is not shown
+ * Bug #1774490 - https://bugzilla.mozilla.org/show_bug.cgi?id=1774490
+ * WebCompat issue #105402 - https://webcompat.com/issues/105402
+ */
+
+.photogallery-swiper .swiper-slide {
+  height: auto;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1784141-aveeno.com-acuvue.com-unsupported.css b/browser/extensions/webcompat/injections/css/bug1784141-aveeno.com-acuvue.com-unsupported.css
new file mode 100644
index 0000000000..50b5bb2e90
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1784141-aveeno.com-acuvue.com-unsupported.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * aveeno.com and acuvue.com - Unsupported message is displayed
+ *
+ * Bug #1784141 - aveeno.com - https://bugzilla.mozilla.org/show_bug.cgi?id=1784141
+ * Bug #1804730 - acuvue.com - https://bugzilla.mozilla.org/show_bug.cgi?id=1804730
+ *
+ * WebCompat issue #103557 - https://webcompat.com/issues/103557
+ * WebCompat issue #103557 - https://webcompat.com/issues/110797
+ */
+
+#browser-alert {
+  display: none !important;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1784199-entrata-platform-unsupported.css b/browser/extensions/webcompat/injections/css/bug1784199-entrata-platform-unsupported.css
new file mode 100644
index 0000000000..d20b84a99b
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1784199-entrata-platform-unsupported.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * aptsovation.com - Unsupported message is displayed on sites based on Entrata platform
+ * Bug #1784199 - https://bugzilla.mozilla.org/show_bug.cgi?id=1784199
+ * WebCompat issue #100131 - https://webcompat.com/issues/100131
+ */
+
+* {
+  color: unset;
+}
+
+#propertyProduct,
+.banner_overlay {
+  display: none;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1799994-www.vivobarefoot.com-product-filters-fix.css b/browser/extensions/webcompat/injections/css/bug1799994-www.vivobarefoot.com-product-filters-fix.css
new file mode 100644
index 0000000000..fd42fd7648
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1799994-www.vivobarefoot.com-product-filters-fix.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * www.vivobarefoot.com - product filters cannot be interacted-with
+ * Bug #1799994 - https://bugzilla.mozilla.org/show_bug.cgi?id=1799994
+ * WebCompat issue #108752 - https://webcompat.com/issues/108752
+ *
+ * The breakage is actually correct behavior, but because of Chrome
+ * bug https://bugs.chromium.org/p/chromium/issues/detail?id=606208
+ * it is currently not breaking on Chrome. We can work around it by
+ * bumping the z-index of the filter options.
+ */
+.page-products .filter-options {
+  z-index: 2;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1800000-www.honda.co.uk-choose-dealer-button-fix.css b/browser/extensions/webcompat/injections/css/bug1800000-www.honda.co.uk-choose-dealer-button-fix.css
new file mode 100644
index 0000000000..5ce3d9f15c
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1800000-www.honda.co.uk-choose-dealer-button-fix.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * www.honda.co.uk- "choose dealer" buttons cannot be interacted-with
+ * Bug #1800000 - https://bugzilla.mozilla.org/show_bug.cgi?id=1800000
+ * WebCompat issue #109242 - https://webcompat.com/issues/109242
+ *
+ * The breakage is actually correct behavior, but because of Chrome
+ * bug https://bugs.chromium.org/p/chromium/issues/detail?id=606208
+ * it is currently not breaking on Chrome. We can work around it by
+ * bumping the z-index of the filter options.
+ */
+.cta-button {
+  z-index: 2;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1819678-nppes.cms.hhs.gov-unsupported-banner.css b/browser/extensions/webcompat/injections/css/bug1819678-nppes.cms.hhs.gov-unsupported-banner.css
new file mode 100644
index 0000000000..ab9788ddc1
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1819678-nppes.cms.hhs.gov-unsupported-banner.css
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * nppes.cms.hhs.gov - Firefox is an unsupported browser
+ * WebCompat issue #119017 - https://github.com/webcompat/web-bugs/issues/119017
+ *
+ * As everything seems to work just fine, this intervention simply hides the
+ * banner.
+ */
+
+#unsupportedDiv {
+  display: none !important;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1829949-tomshardware.com-scrollbar-width.css b/browser/extensions/webcompat/injections/css/bug1829949-tomshardware.com-scrollbar-width.css
new file mode 100644
index 0000000000..f6bee8c878
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1829949-tomshardware.com-scrollbar-width.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * tomshardware.com - a scrollbar covering navigation menu
+ * Bug #1829949 - https://bugzilla.mozilla.org/show_bug.cgi?id=1829949
+ * WebCompat issue #121170 - https://github.com/webcompat/web-bugs/issues/121170
+ *
+ * The scrollbar is covering navigation items and that makes them half hidden.
+ * There are some ::-webkit-scrollbar css rules applied to the scrollbar,
+ * making it thinner. Adding similar rules for Firefox fixes the issue.
+ */
+
+.trending__list {
+  scrollbar-width: thin;
+  scrollbar-color: #000 #f5f5f5;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1829952-eventer.co.il-button-height.css b/browser/extensions/webcompat/injections/css/bug1829952-eventer.co.il-button-height.css
new file mode 100644
index 0000000000..54de51589a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1829952-eventer.co.il-button-height.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * eventer.co.il - a button is covering entire page
+ * Bug #1829952 - https://bugzilla.mozilla.org/show_bug.cgi?id=1829952
+ * WebCompat issue #121296 - https://github.com/webcompat/web-bugs/issues/121296
+ *
+ * The button is covering the page only in Firefox on mobile
+ * because of additional styles applied via @-moz-document url-prefix.
+ * Resetting the height makes the button normal size
+ */
+
+#purchasePageRedesignContainer .mobileStripButton {
+  height: auto;
+  min-height: auto;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1830747-babbel.com-page-height.css b/browser/extensions/webcompat/injections/css/bug1830747-babbel.com-page-height.css
new file mode 100644
index 0000000000..1f7585e637
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1830747-babbel.com-page-height.css
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * my.babbel.com - "Next" button is not visible
+ * Bug #1830747 - https://bugzilla.mozilla.org/show_bug.cgi?id=1830747
+ * WebCompat issue #119212 - https://github.com/webcompat/web-bugs/issues/119212
+ *
+ * The next button on the bottom of the page is not visible in Firefox,
+ * but visible in Chrome since the site is using -webkit-fill-available rule.
+ * Adding height: 100% to the page wrapper allows to see the button.
+ */
+
+[data-main] {
+  height: 100%;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1830752-afisha.ru-slider-pointer-events.css b/browser/extensions/webcompat/injections/css/bug1830752-afisha.ru-slider-pointer-events.css
new file mode 100644
index 0000000000..64974c46e4
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1830752-afisha.ru-slider-pointer-events.css
@@ -0,0 +1,23 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * afisha.ru - Slider not working
+ * Bug #1830752 - https://bugzilla.mozilla.org/show_bug.cgi?id=1830752
+ * WebCompat issue #120455 - https://github.com/webcompat/web-bugs/issues/120455
+ *
+ * The range slider for price filtering is not working because of pointer-events:none applied
+ * on the slider element. It's working in Chrome because of webkit specific rules
+ * set with -moz-range-thumb that override the pointer events on the slider thumb to auto.
+ * Setting the same rule with -moz-range-thumb makes the slider to work.
+ */
+
+.gNPvK::-moz-range-thumb,
+.y5iHc::-moz-range-thumb {
+  background-color: #0050ff;
+  border-color: #0050ff;
+  border-radius: 50%;
+  cursor: pointer;
+  pointer-events: auto;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1830761-91mobiles.com-content-height.css b/browser/extensions/webcompat/injections/css/bug1830761-91mobiles.com-content-height.css
new file mode 100644
index 0000000000..f2e24346e1
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1830761-91mobiles.com-content-height.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * 91mobiles.com - Text overlapping
+ * Bug #1830761 - https://bugzilla.mozilla.org/show_bug.cgi?id=1830761
+ * WebCompat issue #117029 - https://github.com/webcompat/web-bugs/issues/117029
+ *
+ * The content overlaps dedicated space since Firefox honors small heights on <td>
+ * due to https://bugzilla.mozilla.org/show_bug.cgi?id=1461852. Setting the height to
+ * fit-content makes it work as expected.
+ */
+
+#fixed-table tr td .cmp-summary-box,
+.cmpr-table .textpanel {
+  height: fit-content;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1830796-copyleaks.com-hide-unsupported.css b/browser/extensions/webcompat/injections/css/bug1830796-copyleaks.com-hide-unsupported.css
new file mode 100644
index 0000000000..753835de6a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1830796-copyleaks.com-hide-unsupported.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * copyleaks.com - Unsupported message
+ * Bug #1830796 - https://bugzilla.mozilla.org/show_bug.cgi?id=1830796
+ * WebCompat issue #121395 - https://github.com/webcompat/web-bugs/issues/121395
+ */
+
+#outdated {
+  display: none !important;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1830810-interceramic.com-hide-unsupported.css b/browser/extensions/webcompat/injections/css/bug1830810-interceramic.com-hide-unsupported.css
new file mode 100644
index 0000000000..7726140d0e
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1830810-interceramic.com-hide-unsupported.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * interceramic.com - Unsupported message
+ * Bug #1830810 - https://bugzilla.mozilla.org/show_bug.cgi?id=1830810
+ * WebCompat issue #117807 - https://github.com/webcompat/web-bugs/issues/117807
+ */
+
+#ff-modal {
+  display: none !important;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1830813-page.onstove.com-hide-unsupported.css b/browser/extensions/webcompat/injections/css/bug1830813-page.onstove.com-hide-unsupported.css
new file mode 100644
index 0000000000..707e75765e
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1830813-page.onstove.com-hide-unsupported.css
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * onstove.com - Unsupported message
+ * Bug #1830813 - https://bugzilla.mozilla.org/show_bug.cgi?id=1830813
+ * WebCompat issue #116760 - https://github.com/webcompat/web-bugs/issues/116760
+ */
+
+.gnb-alerts.gnb-old-browser {
+  height: 0;
+}
+
+.isCampaign .gnb-stove.gnb-default-fixed,
+.isCampaign .layout.layout-base .layout-header {
+  height: 68px;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1836103-autostar-novoross.ru-make-map-taller.css b/browser/extensions/webcompat/injections/css/bug1836103-autostar-novoross.ru-make-map-taller.css
new file mode 100644
index 0000000000..70fc01b86f
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1836103-autostar-novoross.ru-make-map-taller.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * autostar-novoross.ru - Map is not as tall as expected
+ * Bug #1836103 - https://bugzilla.mozilla.org/show_bug.cgi?id=1836103
+ * WebCompat issue #80763 - https://github.com/webcompat/web-bugs/issues/80763
+ */
+
+.t396 .tn-atom {
+  height: 100%;
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1836105-cnn.com-fix-blank-pages-when-printing.css b/browser/extensions/webcompat/injections/css/bug1836105-cnn.com-fix-blank-pages-when-printing.css
new file mode 100644
index 0000000000..db6f018619
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1836105-cnn.com-fix-blank-pages-when-printing.css
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * cnn.com - Printing in portrait mode results in blank pages
+ * Bug #1836105 - https://bugzilla.mozilla.org/show_bug.cgi?id=1836105
+ *
+ * Disable some of CNN's giant styles for height, top and margin-bottom,
+ * since they break print layout in Firefox (as per bug 1830307)
+ */
+
+@media print {
+  .header__wrapper-outer {
+    height: initial !important;
+    top: initial !important;
+    margin-bottom: initial !important;
+  }
+}
diff --git a/browser/extensions/webcompat/injections/css/bug1836177-clalit.co.il-hide-number-input-spinners.css b/browser/extensions/webcompat/injections/css/bug1836177-clalit.co.il-hide-number-input-spinners.css
new file mode 100644
index 0000000000..ef255c7b89
--- /dev/null
+++ b/browser/extensions/webcompat/injections/css/bug1836177-clalit.co.il-hide-number-input-spinners.css
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * clalit.co.il - Hide number input spinners as page intends
+ * Bug #1836177 - https://bugzilla.mozilla.org/show_bug.cgi?id=1836177
+ * WebCompat issue #109468 - https://github.com/webcompat/web-bugs/issues/109468
+ */
+
+input[type="number"] {
+  -moz-appearance: textfield;
+}
diff --git a/browser/extensions/webcompat/injections/js/bug0000000-testbed-js-injection.js b/browser/extensions/webcompat/injections/js/bug0000000-testbed-js-injection.js
new file mode 100644
index 0000000000..7a192d6c41
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug0000000-testbed-js-injection.js
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals exportFunction */
+
+Object.defineProperty(window.wrappedJSObject, "isTestFeatureSupported", {
+  get: exportFunction(function () {
+    return true;
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1448747-fastclick-shim.js b/browser/extensions/webcompat/injections/js/bug1448747-fastclick-shim.js
new file mode 100644
index 0000000000..7a8e85f538
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1448747-fastclick-shim.js
@@ -0,0 +1,35 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1448747 - Neutralize FastClick
+ *
+ * The patch is applied on sites using FastClick library
+ * to make sure `FastClick.notNeeded` returns `true`.
+ * This allows to disable FastClick and fix various breakage caused
+ * by the library (mainly non-functioning drop-down lists).
+ */
+
+/* globals exportFunction */
+
+(function () {
+  const proto = CSS2Properties.prototype.wrappedJSObject;
+  const descriptor = Object.getOwnPropertyDescriptor(proto, "touchAction");
+  const { get } = descriptor;
+
+  descriptor.get = exportFunction(function () {
+    try {
+      throw Error();
+    } catch (e) {
+      if (e.stack?.includes("notNeeded")) {
+        return "none";
+      }
+    }
+    return get.call(this);
+  }, window);
+
+  Object.defineProperty(proto, "touchAction", descriptor);
+})();
diff --git a/browser/extensions/webcompat/injections/js/bug1452707-window.controllers-shim-ib.absa.co.za.js b/browser/extensions/webcompat/injections/js/bug1452707-window.controllers-shim-ib.absa.co.za.js
new file mode 100644
index 0000000000..40e17b4a36
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1452707-window.controllers-shim-ib.absa.co.za.js
@@ -0,0 +1,33 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1452707 - Build site patch for ib.absa.co.za
+ * WebCompat issue #16401 - https://webcompat.com/issues/16401
+ *
+ * The online banking at ib.absa.co.za detect if window.controllers is a
+ * non-falsy value to detect if the current browser is Firefox or something
+ * else. In bug 1448045, this shim has been disabled for Firefox Nightly 61+,
+ * which breaks the UA detection on this site and results in a "Browser
+ * unsuppored" error message.
+ *
+ * This site patch simply sets window.controllers to a string, resulting in
+ * their check to work again.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "window.controllers has been shimmed for compatibility reasons. See https://webcompat.com/issues/16401 for details."
+);
+
+Object.defineProperty(window.wrappedJSObject, "controllers", {
+  get: exportFunction(function () {
+    return true;
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1457335-histography.io-ua-change.js b/browser/extensions/webcompat/injections/js/bug1457335-histography.io-ua-change.js
new file mode 100644
index 0000000000..06085acc5a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1457335-histography.io-ua-change.js
@@ -0,0 +1,38 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1457335 - histography.io - Override UA & navigator.vendor
+ * WebCompat issue #1804 - https://webcompat.com/issues/1804
+ *
+ * This site is using a strict matching of navigator.userAgent and
+ * navigator.vendor to allow access for Safari or Chrome. Here, we set the
+ * values appropriately so we get recognized as Chrome.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "The user agent has been overridden for compatibility reasons. See https://webcompat.com/issues/1804 for details."
+);
+
+const CHROME_UA = navigator.userAgent + " Chrome for WebCompat";
+
+Object.defineProperty(window.navigator.wrappedJSObject, "userAgent", {
+  get: exportFunction(function () {
+    return CHROME_UA;
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
+
+Object.defineProperty(window.navigator.wrappedJSObject, "vendor", {
+  get: exportFunction(function () {
+    return "Google Inc.";
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1472075-bankofamerica.com-ua-change.js b/browser/extensions/webcompat/injections/js/bug1472075-bankofamerica.com-ua-change.js
new file mode 100644
index 0000000000..5aa72e75ae
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1472075-bankofamerica.com-ua-change.js
@@ -0,0 +1,52 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1472075 - Build UA override for Bank of America for OSX & Linux
+ * WebCompat issue #2787 - https://webcompat.com/issues/2787
+ *
+ * BoA is showing a red warning to Linux and macOS users, while accepting
+ * Windows users without warning. From our side, there is no difference here
+ * and we receive a lot of user complains about the warnings, so we spoof
+ * as Firefox on Windows in those cases.
+ */
+
+/* globals exportFunction */
+
+if (!navigator.platform.includes("Win")) {
+  console.info(
+    "The user agent has been overridden for compatibility reasons. See https://webcompat.com/issues/2787 for details."
+  );
+
+  const WINDOWS_UA = navigator.userAgent.replace(
+    /\(.*; rv:/i,
+    "(Windows NT 10.0; Win64; x64; rv:"
+  );
+
+  Object.defineProperty(window.navigator.wrappedJSObject, "userAgent", {
+    get: exportFunction(function () {
+      return WINDOWS_UA;
+    }, window),
+
+    set: exportFunction(function () {}, window),
+  });
+
+  Object.defineProperty(window.navigator.wrappedJSObject, "appVersion", {
+    get: exportFunction(function () {
+      return "appVersion";
+    }, window),
+
+    set: exportFunction(function () {}, window),
+  });
+
+  Object.defineProperty(window.navigator.wrappedJSObject, "platform", {
+    get: exportFunction(function () {
+      return "Win64";
+    }, window),
+
+    set: exportFunction(function () {}, window),
+  });
+}
diff --git a/browser/extensions/webcompat/injections/js/bug1579159-m.tailieu.vn-pdfjs-worker-disable.js b/browser/extensions/webcompat/injections/js/bug1579159-m.tailieu.vn-pdfjs-worker-disable.js
new file mode 100644
index 0000000000..5c757466c6
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1579159-m.tailieu.vn-pdfjs-worker-disable.js
@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * m.tailieu.vn - Override PDFJS.disableWorker to be true
+ * WebCompat issue #39057 - https://webcompat.com/issues/39057
+ *
+ * Custom viewer built with PDF.js is not working in Firefox for Android
+ * Disabling worker to match Chrome behavior fixes the issue
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "window.PDFJS.disableWorker has been set to true for compatibility reasons. See https://webcompat.com/issues/39057 for details."
+);
+
+let globals = {};
+
+Object.defineProperty(window.wrappedJSObject, "PDFJS", {
+  get: exportFunction(function () {
+    return globals;
+  }, window),
+
+  set: exportFunction(function (value = {}) {
+    globals = value;
+    globals.disableWorker = true;
+  }, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1605611-maps.google.com-directions-time.js b/browser/extensions/webcompat/injections/js/bug1605611-maps.google.com-directions-time.js
new file mode 100644
index 0000000000..a068e8dcd5
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1605611-maps.google.com-directions-time.js
@@ -0,0 +1,38 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1605611 - Cannot change Departure/arrival dates in Google Maps on Android
+ *
+ * This patch re-enables the disabled "Leave now" button.
+ *
+ * See https://bugzilla.mozilla.org/show_bug.cgi?id=1800498 and
+ *     https://bugzilla.mozilla.org/show_bug.cgi?id=1605611 for details.
+ */
+
+const selector =
+  ".ml-directions-searchbox-parent [aria-haspopup=dialog][disabled=true]";
+
+document.addEventListener("DOMContentLoaded", () => {
+  // In case the element appeared before the MutationObserver was activated.
+  for (const elem of document.querySelectorAll(selector)) {
+    elem.disabled = false;
+  }
+  // Start watching for the insertion of the "Leave now" button.
+  const moOptions = {
+    attributeFilter: ["disabled"],
+    attributes: true,
+    subtree: true,
+  };
+  const mo = new MutationObserver(function (records) {
+    for (const { target } of records) {
+      if (target.matches(selector)) {
+        target.disabled = false;
+      }
+    }
+  });
+  mo.observe(document.body, moOptions);
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1631811-datastudio.google.com-indexedDB.js b/browser/extensions/webcompat/injections/js/bug1631811-datastudio.google.com-indexedDB.js
new file mode 100644
index 0000000000..fb9be74039
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1631811-datastudio.google.com-indexedDB.js
@@ -0,0 +1,22 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1631811 - disable indexedDB for datastudio.google.com iframes
+ *
+ * Indexed DB is disabled already for these iframes due to cookie blocking.
+ * This intervention changes the functionality from throwing a SecurityError
+ * when indexedDB is accessed to removing it from the window object
+ */
+
+console.info(
+  "window.indexedDB has been overwritten for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1631811 for details."
+);
+
+Object.defineProperty(window.wrappedJSObject, "indexedDB", {
+  get: undefined,
+  set: undefined,
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1722955-frontgate.com-ua-override.js b/browser/extensions/webcompat/injections/js/bug1722955-frontgate.com-ua-override.js
new file mode 100644
index 0000000000..577a55450a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1722955-frontgate.com-ua-override.js
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/*
+ * Bug 1722955 - Add UA override for frontgate.com
+ * Webcompat issue #36277 - https://github.com/webcompat/web-bugs/issues/36277
+ *
+ * The website is sending the desktop version to Firefox on mobile devices
+ * based on UA sniffing. Spoofing as Chrome fixes this.
+ */
+
+/* globals exportFunction, UAHelpers */
+
+console.info(
+  "The user agent has been overridden for compatibility reasons. See https://webcompat.com/issues/36277 for details."
+);
+
+UAHelpers.overrideWithDeviceAppropriateChromeUA();
diff --git a/browser/extensions/webcompat/injections/js/bug1724764-window-print.js b/browser/extensions/webcompat/injections/js/bug1724764-window-print.js
new file mode 100644
index 0000000000..20e9ecf22d
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1724764-window-print.js
@@ -0,0 +1,28 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Generic window.print shim
+ *
+ * Issues related to an error caused by missing window.print() method on Android.
+ * Adding print to the window object allows to unbreak the sites.
+ */
+
+/* globals exportFunction */
+
+if (typeof window.print === "undefined") {
+  console.info(
+    "window.print has been shimmed for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1659818 for details."
+  );
+
+  Object.defineProperty(window.wrappedJSObject, "print", {
+    get: exportFunction(function () {
+      return true;
+    }, window),
+
+    set: exportFunction(function () {}, window),
+  });
+}
diff --git a/browser/extensions/webcompat/injections/js/bug1724868-news.yahoo.co.jp-ua-override.js b/browser/extensions/webcompat/injections/js/bug1724868-news.yahoo.co.jp-ua-override.js
new file mode 100644
index 0000000000..ab7b76c799
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1724868-news.yahoo.co.jp-ua-override.js
@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1724868 - news.yahoo.co.jp - Override UA
+ * WebCompat issue #82605 - https://webcompat.com/issues/82605
+ *
+ * Yahoo Japan news doesn't allow playing video in Firefox on Android
+ * as they don't have it in their support matrix. They check UA override twice
+ * and display different ui with the same error. Changing UA to Chrome via
+ * content script allows playing the videos.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "The user agent has been overridden for compatibility reasons. See https://webcompat.com/issues/82605 for details."
+);
+
+Object.defineProperty(window.navigator.wrappedJSObject, "userAgent", {
+  get: exportFunction(function () {
+    return "Mozilla/5.0 (Linux; Android 11; Pixel 4a) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.159 Mobile Safari/537.36";
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1731825-office365-email-handling-prompt-autohide.js b/browser/extensions/webcompat/injections/js/bug1731825-office365-email-handling-prompt-autohide.js
new file mode 100644
index 0000000000..d1823aec74
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1731825-office365-email-handling-prompt-autohide.js
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1731825 - Office 365 email handling prompt autohide
+ *
+ * This site patch prevents the notification bar on Office 365
+ * apps from popping up on each page-load, offering to handle
+ * email with Outlook.
+ */
+
+/* globals exportFunction */
+
+const warning =
+  "Office 365 Outlook email handling prompt has been hidden. See https://bugzilla.mozilla.org/show_bug.cgi?id=1731825 for details.";
+
+const localStorageKey = "mailProtocolHandlerAlreadyOffered";
+
+const nav = navigator.wrappedJSObject;
+const { registerProtocolHandler } = nav;
+const { localStorage } = window.wrappedJSObject;
+
+Object.defineProperty(navigator.wrappedJSObject, "registerProtocolHandler", {
+  value: exportFunction(function (scheme, url, title) {
+    if (localStorage.getItem(localStorageKey)) {
+      console.info(warning);
+      return undefined;
+    }
+    registerProtocolHandler.call(nav, scheme, url, title);
+    localStorage.setItem(localStorageKey, true);
+    return undefined;
+  }, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1739489-draftjs-beforeinput.js b/browser/extensions/webcompat/injections/js/bug1739489-draftjs-beforeinput.js
new file mode 100644
index 0000000000..5ae55ec6f3
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1739489-draftjs-beforeinput.js
@@ -0,0 +1,116 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1739489 - Entering an emoji using the MacOS IME "crashes" Draft.js editors.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "textInput event has been remapped to beforeinput for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1739489 for details."
+);
+
+window.wrappedJSObject.TextEvent = window.wrappedJSObject.InputEvent;
+
+const { CustomEvent, Event, EventTarget } = window.wrappedJSObject;
+var Remapped = [
+  [CustomEvent, "constructor"],
+  [Event, "constructor"],
+  [Event, "initEvent"],
+  [EventTarget, "addEventListener"],
+  [EventTarget, "removeEventListener"],
+];
+
+for (const [obj, name] of Remapped) {
+  const { prototype } = obj;
+  const orig = prototype[name];
+  Object.defineProperty(prototype, name, {
+    value: exportFunction(function (type, b, c, d) {
+      if (type?.toLowerCase() === "textinput") {
+        type = "beforeinput";
+      }
+      return orig.call(this, type, b, c, d);
+    }, window),
+  });
+}
+
+if (location.host === "www.reddit.com") {
+  (function () {
+    const EditorCSS = ".public-DraftEditor-content[contenteditable=true]";
+    let obsEditor, obsStart, obsText, obsKey, observer;
+    const obsConfig = { characterData: true, childList: true, subtree: true };
+    const obsHandler = () => {
+      observer.disconnect();
+      const finalTextNode = obsEditor.querySelector(
+        `[data-offset-key="${obsKey}"] [data-text='true']`
+      ).firstChild;
+      const end = obsStart + obsText.length;
+      window
+        .getSelection()
+        .setBaseAndExtent(finalTextNode, end, finalTextNode, end);
+    };
+    observer = new MutationObserver(obsHandler);
+
+    document.documentElement.addEventListener(
+      "beforeinput",
+      e => {
+        if (e.inputType != "insertFromPaste") {
+          return;
+        }
+        const { target } = e;
+        obsEditor = target.closest(EditorCSS);
+        if (!obsEditor) {
+          return;
+        }
+        const items = e?.dataTransfer.items;
+        for (let item of items) {
+          if (item.type === "text/plain") {
+            e.preventDefault();
+            item.getAsString(text => {
+              obsText = text;
+
+              // find the editor-managed <span> which contains the text node the
+              // cursor starts on, and the cursor's location (or the selection start)
+              const sel = window.getSelection();
+              obsStart = sel.anchorOffset;
+              let anchor = sel.anchorNode;
+              if (!anchor.closest) {
+                anchor = anchor.parentElement;
+              }
+              anchor = anchor.closest("[data-offset-key]");
+              obsKey = anchor.getAttribute("data-offset-key");
+
+              // set us up to wait for the editor to either update or replace the
+              // <span> with that key (the one containing the text to be changed).
+              // we will then make sure the cursor is after the pasted text, as if
+              // the editor recreates the node, the cursor position is lost
+              observer.observe(obsEditor, obsConfig);
+
+              // force the editor to "paste". sending paste or other events will not
+              // work, nor using execCommand (adding HTML will screw up the DOM that
+              // the editor expects, and adding plain text will make it ignore newlines).
+              target.dispatchEvent(
+                new InputEvent("beforeinput", {
+                  inputType: "insertText",
+                  data: text,
+                  bubbles: true,
+                  cancelable: true,
+                })
+              );
+
+              // blur the editor to force it to update/flush its state, because otherwise
+              // the paste works, but the editor doesn't show it (until it is re-focused).
+              obsEditor.blur();
+            });
+            break;
+          }
+        }
+      },
+      true
+    );
+  })();
+}
diff --git a/browser/extensions/webcompat/injections/js/bug1769762-tiktok.com-plugins-shim.js b/browser/extensions/webcompat/injections/js/bug1769762-tiktok.com-plugins-shim.js
new file mode 100644
index 0000000000..7383a4e567
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1769762-tiktok.com-plugins-shim.js
@@ -0,0 +1,35 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1769762 - Empty out navigator.plugins
+ * WebCompat issue #103612 - https://webcompat.com/issues/103612
+ *
+ * Certain features of the site are breaking if navigator.plugins array is not empty:
+ *
+ * 1. "Likes" on the comments are not saved
+ * 2. Can't reply to other people's comments
+ * 3. "Likes" on the videos are not saved
+ * 4. Can't follow an account (after refreshing "Follow" button is visible again)
+ *
+ * (note that the first 2 are still broken if you open devtools even with this intervention)
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "The PluginArray has been overridden for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1753874 for details."
+);
+
+const pluginsArray = new window.wrappedJSObject.Array();
+Object.setPrototypeOf(pluginsArray, PluginArray.prototype);
+
+Object.defineProperty(navigator.wrappedJSObject, "plugins", {
+  get: exportFunction(function () {
+    return pluginsArray;
+  }, window),
+  set: exportFunction(function (val) {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1774005-installtrigger-shim.js b/browser/extensions/webcompat/injections/js/bug1774005-installtrigger-shim.js
new file mode 100644
index 0000000000..ca7ef5b6c5
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1774005-installtrigger-shim.js
@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1774005 - Generic window.InstallTrigger shim
+ *
+ * This interventions shims window.InstallTrigger to a string, which evaluates
+ * as `true` in web developers browser sniffing code. This intervention will
+ * be applied to multiple domains, see bug 1774005 for more information.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "The InstallTrigger has been shimmed for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1774005 for details."
+);
+
+Object.defineProperty(window.wrappedJSObject, "InstallTrigger", {
+  get: exportFunction(function () {
+    return "This property has been shimed for Web Compatibility reasons.";
+  }, window),
+  set: exportFunction(function (_) {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1784302-effectiveType-shim.js b/browser/extensions/webcompat/injections/js/bug1784302-effectiveType-shim.js
new file mode 100644
index 0000000000..7bde4a7d82
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1784302-effectiveType-shim.js
@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1784302 - Issues due to missing navigator.connection after
+ * https://bugzilla.mozilla.org/show_bug.cgi?id=1637922 landed.
+ * Webcompat issue #104838 - https://github.com/webcompat/web-bugs/issues/104838
+ */
+
+/* globals cloneInto, exportFunction */
+
+console.info(
+  "navigator.connection has been shimmed for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1756692 for details."
+);
+
+var connection = {
+  addEventListener: () => {},
+  removeEventListener: () => {},
+  effectiveType: "4g",
+};
+
+window.navigator.wrappedJSObject.connection = cloneInto(connection, window, {
+  cloneFunctions: true,
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1795490-www.china-airlines.com-undisable-date-fields-on-mobile.js b/browser/extensions/webcompat/injections/js/bug1795490-www.china-airlines.com-undisable-date-fields-on-mobile.js
new file mode 100644
index 0000000000..f3c0e03513
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1795490-www.china-airlines.com-undisable-date-fields-on-mobile.js
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1795490 - Cannot use date fields on China Airlines mobile page
+ *
+ * This patch ensures that the search input never has the [disabled]
+ * attribute, so that users may tap/click on it to search.
+ *
+ * See https://bugzilla.mozilla.org/show_bug.cgi?id=1795490 for details.
+ */
+
+const SELECTOR = `#departureDateMobile[disabled], #returnDateMobile[disabled]`;
+
+function check(target) {
+  if (target.nodeName === "INPUT" && target.matches(SELECTOR)) {
+    target.removeAttribute("disabled");
+    return true;
+  }
+  return false;
+}
+
+new MutationObserver(mutations => {
+  for (const { addedNodes, target, attributeName } of mutations) {
+    if (attributeName === "disabled") {
+      check(target);
+    } else {
+      addedNodes?.forEach(node => {
+        if (!check(node)) {
+          node
+            .querySelectorAll?.(SELECTOR)
+            ?.forEach(n => n.removeAttribute("disabled"));
+        }
+      });
+    }
+  }
+}).observe(document, { attributes: true, childList: true, subtree: true });
diff --git a/browser/extensions/webcompat/injections/js/bug1799968-www.samsung.com-appVersion-linux-fix.js b/browser/extensions/webcompat/injections/js/bug1799968-www.samsung.com-appVersion-linux-fix.js
new file mode 100644
index 0000000000..941f071e2c
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1799968-www.samsung.com-appVersion-linux-fix.js
@@ -0,0 +1,31 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1799968 - Build site patch for www.samsung.com
+ * WebCompat issue #108993 - https://webcompat.com/issues/108993
+ *
+ * Samsung's Watch pages try to detect the OS via navigator.appVersion,
+ * but fail with Linux because they expect it to contain the literal
+ * string "linux", and their JS breaks.
+ *
+ * As such this site patch sets appVersion to "5.0 (Linux)", and is
+ * only meant to be applied on Linux.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "navigator.appVersion has been shimmed for compatibility reasons. See https://webcompat.com/issues/108993 for details."
+);
+
+Object.defineProperty(navigator.wrappedJSObject, "appVersion", {
+  get: exportFunction(function () {
+    return "5.0 (Linux)";
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1799980-healow.com-infinite-loop-fix.js b/browser/extensions/webcompat/injections/js/bug1799980-healow.com-infinite-loop-fix.js
new file mode 100644
index 0000000000..191e97dec1
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1799980-healow.com-infinite-loop-fix.js
@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1799980 - Healow gets stuck in an infinite loop while pages load
+ *
+ * This patch keeps Healow's localization scripts from getting stuck in
+ * an infinite loop while their pages are loading.
+ *
+ * This happens because they use synchronous XMLHttpRequests to fetch a
+ * JSON file with their localized text on the first call to their i18n
+ * function, and then force subsequent calls to wait for it by waiting
+ * in an infinite loop.
+ *
+ * But since they're in an infinite loop, the code after the syncXHR will
+ * never be able to run, so this ultimately triggers a slow script warning.
+ *
+ * We can improve this by just preventing the infinite loop from happening,
+ * though since they disable caching on their JSON files it means that more
+ * XHRs may happen. But since those files are small, this seems like a
+ * reasonable compromise until they migrate to a better i18n solution.
+ *
+ * See https://bugzilla.mozilla.org/show_bug.cgi?id=1799980 for details.
+ */
+
+/* globals exportFunction */
+
+Object.defineProperty(window.wrappedJSObject, "ajaxRequestProcessing", {
+  get: exportFunction(function () {
+    return false;
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1818818-fastclick-legacy-shim.js b/browser/extensions/webcompat/injections/js/bug1818818-fastclick-legacy-shim.js
new file mode 100644
index 0000000000..91f1c1a19a
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1818818-fastclick-legacy-shim.js
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1818818 - Neutralize FastClick
+ *
+ * The patch is applied on sites using older version of FastClick library.
+ * This allows to disable FastClick and fix various breakage caused
+ * by the library.
+ */
+
+/* globals exportFunction */
+
+const proto = CSS2Properties.prototype.wrappedJSObject;
+Object.defineProperty(proto, "msTouchAction", {
+  get: exportFunction(function () {
+    return "none";
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1819450-cmbchina.com-ua-change.js b/browser/extensions/webcompat/injections/js/bug1819450-cmbchina.com-ua-change.js
new file mode 100644
index 0000000000..bbe76c465f
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1819450-cmbchina.com-ua-change.js
@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1819450 - cmbchina.com - Override UA
+ *
+ * The site is using UA detection to redirect to
+ * m.cmbchina.com (mobile version of the site). Adding `SAMSUNG` allows
+ * to bypass the detection of mobile browser.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "The user agent has been overridden for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1081239 for details."
+);
+
+const MODIFIED_UA = navigator.userAgent + " SAMSUNG";
+
+Object.defineProperty(window.navigator.wrappedJSObject, "userAgent", {
+  get: exportFunction(function () {
+    return MODIFIED_UA;
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1819476-axisbank.com-webkitSpeechRecognition-shim.js b/browser/extensions/webcompat/injections/js/bug1819476-axisbank.com-webkitSpeechRecognition-shim.js
new file mode 100644
index 0000000000..a72e938e4f
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1819476-axisbank.com-webkitSpeechRecognition-shim.js
@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * axisbank.com - Shim webkitSpeechRecognition
+ * WebCompat issue #117770 - https://webcompat.com/issues/117770
+ *
+ * The page with bank offerings is not loading options due to the
+ * site relying on webkitSpeechRecognition, which is undefined in Firefox.
+ * Shimming it to `class {}` makes the pages work.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "webkitSpeechRecognition was shimmed for compatibility reasons. See https://webcompat.com/issues/117770 for details."
+);
+
+Object.defineProperty(window.wrappedJSObject, "webkitSpeechRecognition", {
+  value: exportFunction(function () {
+    return class {};
+  }, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1819678-cnki.net-undisable-search-field.js b/browser/extensions/webcompat/injections/js/bug1819678-cnki.net-undisable-search-field.js
new file mode 100644
index 0000000000..c230feb43d
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1819678-cnki.net-undisable-search-field.js
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1819678 - cnki.net - Cannot use search field
+ * WebCompat issue #115777 - https://webcompat.com/issues/115777
+ *
+ * This patch ensures that the search input never has the [disabled]
+ * attribute, so that users may tap/click on it to search.
+ *
+ * See https://bugzilla.mozilla.org/show_bug.cgi?id=1819678 for details.
+ */
+
+console.info(
+  "search input disabled attribute was removed for compatibility reasons. See https://webcompat.com/issues/115777 for details."
+);
+
+const SELECTOR = `.searchimg[disabled]`;
+
+function check(target) {
+  if (target.nodeName === "INPUT" && target.matches(SELECTOR)) {
+    target.removeAttribute("disabled");
+    return true;
+  }
+  return false;
+}
+
+new MutationObserver(mutations => {
+  for (const { addedNodes, target, attributeName } of mutations) {
+    if (attributeName === "disabled") {
+      check(target);
+    } else {
+      addedNodes?.forEach(node => {
+        if (!check(node)) {
+          node
+            .querySelectorAll?.(SELECTOR)
+            ?.forEach(n => n.removeAttribute("disabled"));
+        }
+      });
+    }
+  }
+}).observe(document, { attributes: true, childList: true, subtree: true });
diff --git a/browser/extensions/webcompat/injections/js/bug1819678-free4talk.com-window-chrome-shim.js b/browser/extensions/webcompat/injections/js/bug1819678-free4talk.com-window-chrome-shim.js
new file mode 100644
index 0000000000..6e6b5823cb
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1819678-free4talk.com-window-chrome-shim.js
@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1827678 - UA spoof for www.free4talk.com
+ *
+ * This site is checking for window.chrome, so let's spoof that.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "window.chrome has been shimmed for compatibility reasons. See https://github.com/webcompat/web-bugs/issues/77727 for details."
+);
+
+Object.defineProperty(window.wrappedJSObject, "chrome", {
+  get: exportFunction(function () {
+    return true;
+  }, window),
+
+  set: exportFunction(function () {}, window),
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1830776-blueshieldca.com-unsupported.js b/browser/extensions/webcompat/injections/js/bug1830776-blueshieldca.com-unsupported.js
new file mode 100644
index 0000000000..2b1eb11baf
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1830776-blueshieldca.com-unsupported.js
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1830776 - blueshieldca.com
+ * WebCompat issue #112630 - https://webcompat.com/issues/112630
+ *
+ * The site is showing unsupported message in Firefox.
+ * They're also checking for "browserCollapsed" item in sessionStorage
+ * before showing the message, to only show it once. Adding this
+ * item to sessionStorage will make sure the message is not shown
+ * on the initial load.
+ */
+
+console.info(
+  "browserCollapsed in sessionStorage has been shimmed for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1830776 for details."
+);
+
+if (!sessionStorage.getItem("browserCollapsed")) {
+  sessionStorage.setItem("browserCollapsed", "true");
+}
diff --git a/browser/extensions/webcompat/injections/js/bug1831007-nintendo-window-OnetrustActiveGroups.js b/browser/extensions/webcompat/injections/js/bug1831007-nintendo-window-OnetrustActiveGroups.js
new file mode 100644
index 0000000000..433c416770
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1831007-nintendo-window-OnetrustActiveGroups.js
@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1831007 - Shim window.OnetrustActiveGroups for Nintendo sites
+ *
+ * Nintendo relies on `window.OnetrustActiveGroups` being defined. If it's not,
+ * users may have intermittent issues signing into their account, as they're
+ * then trying to call `.split()` on `undefined`.
+ *
+ * This intervention sets a default value (an empty string), but still allows
+ * the value to be overwritten at any time.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "The window.OnetrustActiveGroups property has been shimmed for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1831007 for details."
+);
+
+Object.defineProperty(window.wrappedJSObject, "OnetrustActiveGroups", {
+  value: "",
+  writable: true,
+});
diff --git a/browser/extensions/webcompat/injections/js/bug1836157-thai-masszazs-niceScroll-disable.js b/browser/extensions/webcompat/injections/js/bug1836157-thai-masszazs-niceScroll-disable.js
new file mode 100644
index 0000000000..719267748b
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1836157-thai-masszazs-niceScroll-disable.js
@@ -0,0 +1,23 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Bug 1836157 - Shim navigator.platform on www.thai-massaszs.net/en/
+ *
+ * This page adds niceScroll on Android, which breaks scrolling and
+ * zooming on Firefox. Adding ` Mac` to `navigator.platform` makes
+ * the page avoid adding niceScroll entirely, unbreaking the page.
+ */
+
+var plat = navigator.platform;
+if (!plat.includes("Mac")) {
+  console.info(
+    "The navigator.platform property has been shimmed to include 'Mac' for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1836157 for details."
+  );
+
+  Object.defineProperty(navigator.__proto__.wrappedJSObject, "platform", {
+    value: plat + " Mac",
+    writable: true,
+  });
+}
diff --git a/browser/extensions/webcompat/injections/js/bug1842437-www.youtube.com-performance-now-precision.js b/browser/extensions/webcompat/injections/js/bug1842437-www.youtube.com-performance-now-precision.js
new file mode 100644
index 0000000000..2d328de108
--- /dev/null
+++ b/browser/extensions/webcompat/injections/js/bug1842437-www.youtube.com-performance-now-precision.js
@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1842437 - When attempting to go back on youtube.com, the content remains the same
+ *
+ * If consecutive session history entries had history.state.entryTime set to same value,
+ * back button doesn't work as expected. The entryTime value is coming from performance.now()
+ * and modifying its return value slightly to make sure two close consecutive calls don't
+ * get the same result helped with resolving the issue.
+ */
+
+/* globals exportFunction */
+
+console.info(
+  "performance.now precision has been modified for compatibility reasons. See https://bugzilla.mozilla.org/show_bug.cgi?id=1756970 for details."
+);
+
+const origPerf = performance.wrappedJSObject;
+const origNow = origPerf.now;
+
+let counter = 0;
+let previousVal = 0;
+
+Object.defineProperty(window.performance.wrappedJSObject, "now", {
+  value: exportFunction(function () {
+    let originalVal = origNow.call(origPerf);
+    if (originalVal === previousVal) {
+      originalVal += 0.00000003 * ++counter;
+    } else {
+      previousVal = originalVal;
+      counter = 0;
+    }
+    return originalVal;
+  }, window),
+});
diff --git a/browser/extensions/webcompat/lib/about_compat_broker.js b/browser/extensions/webcompat/lib/about_compat_broker.js
new file mode 100644
index 0000000000..faaa56a38e
--- /dev/null
+++ b/browser/extensions/webcompat/lib/about_compat_broker.js
@@ -0,0 +1,141 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* global browser, module, onMessageFromTab */
+
+class AboutCompatBroker {
+  constructor(bindings) {
+    this._injections = bindings.injections;
+    this._uaOverrides = bindings.uaOverrides;
+    this._shims = bindings.shims;
+
+    if (!this._injections && !this._uaOverrides && !this._shims) {
+      throw new Error("No interventions; about:compat broker is not needed");
+    }
+
+    this.portsToAboutCompatTabs = this.buildPorts();
+    this._injections?.bindAboutCompatBroker(this);
+    this._uaOverrides?.bindAboutCompatBroker(this);
+    this._shims?.bindAboutCompatBroker(this);
+  }
+
+  buildPorts() {
+    const ports = new Set();
+
+    browser.runtime.onConnect.addListener(port => {
+      ports.add(port);
+      port.onDisconnect.addListener(function () {
+        ports.delete(port);
+      });
+    });
+
+    async function broadcast(message) {
+      for (const port of ports) {
+        port.postMessage(message);
+      }
+    }
+
+    return { broadcast };
+  }
+
+  filterOverrides(overrides) {
+    return overrides
+      .filter(override => override.availableOnPlatform)
+      .map(override => {
+        const { id, active, bug, domain, hidden } = override;
+        return { id, active, bug, domain, hidden };
+      });
+  }
+
+  getInterventionById(id) {
+    for (const [type, things] of Object.entries({
+      overrides: this._uaOverrides?.getAvailableOverrides() || [],
+      interventions: this._injections?.getAvailableInjections() || [],
+      shims: this._shims?.getAvailableShims() || [],
+    })) {
+      for (const what of things) {
+        if (what.id === id) {
+          return { type, what };
+        }
+      }
+    }
+    return {};
+  }
+
+  bootup() {
+    onMessageFromTab(msg => {
+      switch (msg.command || msg) {
+        case "toggle": {
+          const id = msg.id;
+          const { type, what } = this.getInterventionById(id);
+          if (!what) {
+            return Promise.reject(
+              `No such override or intervention to toggle: ${id}`
+            );
+          }
+          const active = type === "shims" ? !what.disabledReason : what.active;
+          this.portsToAboutCompatTabs
+            .broadcast({ toggling: id, active })
+            .then(async () => {
+              switch (type) {
+                case "interventions": {
+                  if (active) {
+                    await this._injections?.disableInjection(what);
+                  } else {
+                    await this._injections?.enableInjection(what);
+                  }
+                  break;
+                }
+                case "overrides": {
+                  if (active) {
+                    await this._uaOverrides?.disableOverride(what);
+                  } else {
+                    await this._uaOverrides?.enableOverride(what);
+                  }
+                  break;
+                }
+                case "shims": {
+                  if (active) {
+                    await this._shims?.disableShimForSession(id);
+                  } else {
+                    await this._shims?.enableShimForSession(id);
+                  }
+                  // no need to broadcast the "toggled" signal for shims, as
+                  // they send a shimsUpdated message themselves instead
+                  return;
+                }
+              }
+              this.portsToAboutCompatTabs.broadcast({
+                toggled: id,
+                active: !active,
+              });
+            });
+          break;
+        }
+        case "getAllInterventions": {
+          return Promise.resolve({
+            overrides:
+              (this._uaOverrides?.isEnabled() &&
+                this.filterOverrides(
+                  this._uaOverrides?.getAvailableOverrides()
+                )) ||
+              false,
+            interventions:
+              (this._injections?.isEnabled() &&
+                this.filterOverrides(
+                  this._injections?.getAvailableInjections()
+                )) ||
+              false,
+            shims: this._shims?.getAvailableShims() || false,
+          });
+        }
+      }
+      return undefined;
+    });
+  }
+}
+
+module.exports = AboutCompatBroker;
diff --git a/browser/extensions/webcompat/lib/custom_functions.js b/browser/extensions/webcompat/lib/custom_functions.js
new file mode 100644
index 0000000000..97603e0424
--- /dev/null
+++ b/browser/extensions/webcompat/lib/custom_functions.js
@@ -0,0 +1,109 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser, module */
+
+const replaceStringInRequest = (
+  requestId,
+  inString,
+  outString,
+  inEncoding = "utf-8"
+) => {
+  const filter = browser.webRequest.filterResponseData(requestId);
+  const decoder = new TextDecoder(inEncoding);
+  const encoder = new TextEncoder();
+  const RE = new RegExp(inString, "g");
+  const carryoverLength = inString.length;
+  let carryover = "";
+
+  filter.ondata = event => {
+    const replaced = (
+      carryover + decoder.decode(event.data, { stream: true })
+    ).replace(RE, outString);
+    filter.write(encoder.encode(replaced.slice(0, -carryoverLength)));
+    carryover = replaced.slice(-carryoverLength);
+  };
+
+  filter.onstop = event => {
+    if (carryover.length) {
+      filter.write(encoder.encode(carryover));
+    }
+    filter.close();
+  };
+};
+
+const CUSTOM_FUNCTIONS = {
+  detectSwipeFix: injection => {
+    const { urls, types } = injection.data;
+    const listener = (injection.data.listener = ({ requestId }) => {
+      replaceStringInRequest(
+        requestId,
+        "preventDefault:true",
+        "preventDefault:false"
+      );
+      return {};
+    });
+    browser.webRequest.onBeforeRequest.addListener(listener, { urls, types }, [
+      "blocking",
+    ]);
+  },
+  detectSwipeFixDisable: injection => {
+    const { listener } = injection.data;
+    browser.webRequest.onBeforeRequest.removeListener(listener);
+    delete injection.data.listener;
+  },
+  noSniffFix: injection => {
+    const { urls, contentType } = injection.data;
+    const listener = (injection.data.listener = e => {
+      e.responseHeaders.push(contentType);
+      return { responseHeaders: e.responseHeaders };
+    });
+
+    browser.webRequest.onHeadersReceived.addListener(listener, { urls }, [
+      "blocking",
+      "responseHeaders",
+    ]);
+  },
+  noSniffFixDisable: injection => {
+    const { listener } = injection.data;
+    browser.webRequest.onHeadersReceived.removeListener(listener);
+    delete injection.data.listener;
+  },
+  runScriptBeforeRequest: injection => {
+    const { bug, message, request, script, types } = injection;
+    const warning = `${message} See https://bugzilla.mozilla.org/show_bug.cgi?id=${bug} for details.`;
+
+    const listener = (injection.listener = e => {
+      const { tabId, frameId } = e;
+      return browser.tabs
+        .executeScript(tabId, {
+          file: script,
+          frameId,
+          runAt: "document_start",
+        })
+        .then(() => {
+          browser.tabs.executeScript(tabId, {
+            code: `console.warn(${JSON.stringify(warning)})`,
+            runAt: "document_start",
+          });
+        })
+        .catch(_ => {});
+    });
+
+    browser.webRequest.onBeforeRequest.addListener(
+      listener,
+      { urls: request, types: types || ["script"] },
+      ["blocking"]
+    );
+  },
+  runScriptBeforeRequestDisable: injection => {
+    const { listener } = injection;
+    browser.webRequest.onBeforeRequest.removeListener(listener);
+    delete injection.data.listener;
+  },
+};
+
+module.exports = CUSTOM_FUNCTIONS;
diff --git a/browser/extensions/webcompat/lib/injections.js b/browser/extensions/webcompat/lib/injections.js
new file mode 100644
index 0000000000..8760f551c7
--- /dev/null
+++ b/browser/extensions/webcompat/lib/injections.js
@@ -0,0 +1,165 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser, module */
+
+class Injections {
+  constructor(availableInjections, customFunctions) {
+    this.INJECTION_PREF = "perform_injections";
+
+    this._injectionsEnabled = true;
+
+    this._availableInjections = availableInjections;
+    this._activeInjections = new Map();
+    this._customFunctions = customFunctions;
+  }
+
+  bindAboutCompatBroker(broker) {
+    this._aboutCompatBroker = broker;
+  }
+
+  bootup() {
+    browser.aboutConfigPrefs.onPrefChange.addListener(() => {
+      this.checkInjectionPref();
+    }, this.INJECTION_PREF);
+    this.checkInjectionPref();
+  }
+
+  checkInjectionPref() {
+    browser.aboutConfigPrefs.getPref(this.INJECTION_PREF).then(value => {
+      if (value === undefined) {
+        browser.aboutConfigPrefs.setPref(this.INJECTION_PREF, true);
+      } else if (value === false) {
+        this.unregisterContentScripts();
+      } else {
+        this.registerContentScripts();
+      }
+    });
+  }
+
+  getAvailableInjections() {
+    return this._availableInjections;
+  }
+
+  isEnabled() {
+    return this._injectionsEnabled;
+  }
+
+  async registerContentScripts() {
+    const platformInfo = await browser.runtime.getPlatformInfo();
+    const platformMatches = [
+      "all",
+      platformInfo.os,
+      platformInfo.os == "android" ? "android" : "desktop",
+    ];
+    for (const injection of this._availableInjections) {
+      if (platformMatches.includes(injection.platform)) {
+        injection.availableOnPlatform = true;
+        await this.enableInjection(injection);
+      }
+    }
+
+    this._injectionsEnabled = true;
+    this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
+      interventionsChanged: this._aboutCompatBroker.filterOverrides(
+        this._availableInjections
+      ),
+    });
+  }
+
+  assignContentScriptDefaults(contentScripts) {
+    let finalConfig = Object.assign({}, contentScripts);
+
+    if (!finalConfig.runAt) {
+      finalConfig.runAt = "document_start";
+    }
+
+    return finalConfig;
+  }
+
+  async enableInjection(injection) {
+    if (injection.active) {
+      return undefined;
+    }
+
+    if (injection.customFunc) {
+      return this.enableCustomInjection(injection);
+    }
+
+    return this.enableContentScripts(injection);
+  }
+
+  enableCustomInjection(injection) {
+    if (injection.customFunc in this._customFunctions) {
+      this._customFunctions[injection.customFunc](injection);
+      injection.active = true;
+    } else {
+      console.error(
+        `Provided function ${injection.customFunc} wasn't found in functions list`
+      );
+    }
+  }
+
+  async enableContentScripts(injection) {
+    try {
+      const handle = await browser.contentScripts.register(
+        this.assignContentScriptDefaults(injection.contentScripts)
+      );
+      this._activeInjections.set(injection, handle);
+      injection.active = true;
+    } catch (ex) {
+      console.error(
+        "Registering WebCompat GoFaster content scripts failed: ",
+        ex
+      );
+    }
+  }
+
+  unregisterContentScripts() {
+    for (const injection of this._availableInjections) {
+      this.disableInjection(injection);
+    }
+
+    this._injectionsEnabled = false;
+    this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
+      interventionsChanged: false,
+    });
+  }
+
+  async disableInjection(injection) {
+    if (!injection.active) {
+      return undefined;
+    }
+
+    if (injection.customFunc) {
+      return this.disableCustomInjections(injection);
+    }
+
+    return this.disableContentScripts(injection);
+  }
+
+  disableCustomInjections(injection) {
+    const disableFunc = injection.customFunc + "Disable";
+
+    if (disableFunc in this._customFunctions) {
+      this._customFunctions[disableFunc](injection);
+      injection.active = false;
+    } else {
+      console.error(
+        `Provided function ${disableFunc} for disabling injection wasn't found in functions list`
+      );
+    }
+  }
+
+  async disableContentScripts(injection) {
+    const contentScript = this._activeInjections.get(injection);
+    await contentScript.unregister();
+    this._activeInjections.delete(injection);
+    injection.active = false;
+  }
+}
+
+module.exports = Injections;
diff --git a/browser/extensions/webcompat/lib/intervention_helpers.js b/browser/extensions/webcompat/lib/intervention_helpers.js
new file mode 100644
index 0000000000..16ea6572f2
--- /dev/null
+++ b/browser/extensions/webcompat/lib/intervention_helpers.js
@@ -0,0 +1,233 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals module */
+
+const GOOGLE_TLDS = [
+  "com",
+  "ac",
+  "ad",
+  "ae",
+  "com.af",
+  "com.ag",
+  "com.ai",
+  "al",
+  "am",
+  "co.ao",
+  "com.ar",
+  "as",
+  "at",
+  "com.au",
+  "az",
+  "ba",
+  "com.bd",
+  "be",
+  "bf",
+  "bg",
+  "com.bh",
+  "bi",
+  "bj",
+  "com.bn",
+  "com.bo",
+  "com.br",
+  "bs",
+  "bt",
+  "co.bw",
+  "by",
+  "com.bz",
+  "ca",
+  "com.kh",
+  "cc",
+  "cd",
+  "cf",
+  "cat",
+  "cg",
+  "ch",
+  "ci",
+  "co.ck",
+  "cl",
+  "cm",
+  "cn",
+  "com.co",
+  "co.cr",
+  "com.cu",
+  "cv",
+  "com.cy",
+  "cz",
+  "de",
+  "dj",
+  "dk",
+  "dm",
+  "com.do",
+  "dz",
+  "com.ec",
+  "ee",
+  "com.eg",
+  "es",
+  "com.et",
+  "fi",
+  "com.fj",
+  "fm",
+  "fr",
+  "ga",
+  "ge",
+  "gf",
+  "gg",
+  "com.gh",
+  "com.gi",
+  "gl",
+  "gm",
+  "gp",
+  "gr",
+  "com.gt",
+  "gy",
+  "com.hk",
+  "hn",
+  "hr",
+  "ht",
+  "hu",
+  "co.id",
+  "iq",
+  "ie",
+  "co.il",
+  "im",
+  "co.in",
+  "io",
+  "is",
+  "it",
+  "je",
+  "com.jm",
+  "jo",
+  "co.jp",
+  "co.ke",
+  "ki",
+  "kg",
+  "co.kr",
+  "com.kw",
+  "kz",
+  "la",
+  "com.lb",
+  "com.lc",
+  "li",
+  "lk",
+  "co.ls",
+  "lt",
+  "lu",
+  "lv",
+  "com.ly",
+  "co.ma",
+  "md",
+  "me",
+  "mg",
+  "mk",
+  "ml",
+  "com.mm",
+  "mn",
+  "ms",
+  "com.mt",
+  "mu",
+  "mv",
+  "mw",
+  "com.mx",
+  "com.my",
+  "co.mz",
+  "com.na",
+  "ne",
+  "com.nf",
+  "com.ng",
+  "com.ni",
+  "nl",
+  "no",
+  "com.np",
+  "nr",
+  "nu",
+  "co.nz",
+  "com.om",
+  "com.pk",
+  "com.pa",
+  "com.pe",
+  "com.ph",
+  "pl",
+  "com.pg",
+  "pn",
+  "com.pr",
+  "ps",
+  "pt",
+  "com.py",
+  "com.qa",
+  "ro",
+  "rs",
+  "ru",
+  "rw",
+  "com.sa",
+  "com.sb",
+  "sc",
+  "se",
+  "com.sg",
+  "sh",
+  "si",
+  "sk",
+  "com.sl",
+  "sn",
+  "sm",
+  "so",
+  "st",
+  "sr",
+  "com.sv",
+  "td",
+  "tg",
+  "co.th",
+  "com.tj",
+  "tk",
+  "tl",
+  "tm",
+  "to",
+  "tn",
+  "com.tr",
+  "tt",
+  "com.tw",
+  "co.tz",
+  "com.ua",
+  "co.ug",
+  "co.uk",
+  "com",
+  "com.uy",
+  "co.uz",
+  "com.vc",
+  "co.ve",
+  "vg",
+  "co.vi",
+  "com.vn",
+  "vu",
+  "ws",
+  "co.za",
+  "co.zm",
+  "co.zw",
+];
+
+var InterventionHelpers = {
+  /**
+   * Useful helper to generate a list of domains with a fixed base domain and
+   * multiple country-TLDs or other cases with various TLDs.
+   *
+   * Example:
+   *   matchPatternsForTLDs("*://mozilla.", "/*", ["com", "org"])
+   *     => ["*://mozilla.com/*", "*://mozilla.org/*"]
+   */
+  matchPatternsForTLDs(base, suffix, tlds) {
+    return tlds.map(tld => base + tld + suffix);
+  },
+
+  /**
+   * A modified version of matchPatternsForTLDs that always returns the match
+   * list for all known Google country TLDs.
+   */
+  matchPatternsForGoogle(base, suffix = "/*") {
+    return InterventionHelpers.matchPatternsForTLDs(base, suffix, GOOGLE_TLDS);
+  },
+};
+
+module.exports = InterventionHelpers;
diff --git a/browser/extensions/webcompat/lib/messaging_helper.js b/browser/extensions/webcompat/lib/messaging_helper.js
new file mode 100644
index 0000000000..d978ed384f
--- /dev/null
+++ b/browser/extensions/webcompat/lib/messaging_helper.js
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+// By default, only the first handler for browser.runtime.onMessage which
+// returns a value will get to return one. As such, we need to let them all
+// receive the message, and all have a chance to return a response (with the
+// first non-undefined result being the one that is ultimately returned).
+// This way, about:compat and the shims library can both get a chance to
+// process a message, and just return undefined if they wish to ignore it.
+
+const onMessageFromTab = (function () {
+  const handlers = new Set();
+
+  browser.runtime.onMessage.addListener((msg, sender) => {
+    const promises = [...handlers.values()].map(fn => fn(msg, sender));
+    return Promise.allSettled(promises).then(results => {
+      for (const { reason, value } of results) {
+        if (reason) {
+          console.error(reason);
+        } else if (value !== undefined) {
+          return value;
+        }
+      }
+      return undefined;
+    });
+  });
+
+  return function (handler) {
+    handlers.add(handler);
+  };
+})();
diff --git a/browser/extensions/webcompat/lib/module_shim.js b/browser/extensions/webcompat/lib/module_shim.js
new file mode 100644
index 0000000000..2fd39fdbbd
--- /dev/null
+++ b/browser/extensions/webcompat/lib/module_shim.js
@@ -0,0 +1,24 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * We cannot yet use proper JS modules within webextensions, as support for them
+ * is highly experimental and highly instable. So we end up just including all
+ * the JS files we need as separate background scripts, and since they all are
+ * executed within the same context, this works for our in-browser deployment.
+ *
+ * However, this code is tracked outside of mozilla-central, and we work on
+ * shipping this code in other products, like android-components as well.
+ * Because of that, we have automated tests running within that repository. To
+ * make our lives easier, we add `module.exports` statements to the JS source
+ * files, so we can easily import their contents into our NodeJS-based test
+ * suite.
+ *
+ * This works fine, but obviously, `module` is not defined when running
+ * in-browser. So let's use this empty object as a shim, so we don't run into
+ * runtime exceptions because of that.
+ */
+var module = {};
diff --git a/browser/extensions/webcompat/lib/requestStorageAccess_helper.js b/browser/extensions/webcompat/lib/requestStorageAccess_helper.js
new file mode 100644
index 0000000000..032225bb78
--- /dev/null
+++ b/browser/extensions/webcompat/lib/requestStorageAccess_helper.js
@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* globals browser */
+
+// Helper for calling the internal requestStorageAccessForOrigin method. The
+// method is called on the first-party document for the third-party which needs
+// first-party storage access.
+browser.runtime.onMessage.addListener(request => {
+  let { requestStorageAccessOrigin, warning } = request;
+  if (!requestStorageAccessOrigin) {
+    return false;
+  }
+
+  // Log a warning to the web console, informing about the shim.
+  console.warn(warning);
+
+  // Call the internal storage access API. Passing false means we don't require
+  // user activation, but will always show the storage access prompt. The user
+  // has to explicitly allow storage access.
+  return document
+    .requestStorageAccessForOrigin(requestStorageAccessOrigin, false)
+    .then(() => {
+      return { success: true };
+    })
+    .catch(() => {
+      return { success: false };
+    });
+});
diff --git a/browser/extensions/webcompat/lib/shim_messaging_helper.js b/browser/extensions/webcompat/lib/shim_messaging_helper.js
new file mode 100644
index 0000000000..ee109713a5
--- /dev/null
+++ b/browser/extensions/webcompat/lib/shim_messaging_helper.js
@@ -0,0 +1,65 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+if (!window.Shims) {
+  window.Shims = new Map();
+}
+
+if (!window.ShimsHelperReady) {
+  window.ShimsHelperReady = true;
+
+  browser.runtime.onMessage.addListener(details => {
+    const { shimId, warning } = details;
+    if (!shimId) {
+      return;
+    }
+    window.Shims.set(shimId, details);
+    if (warning) {
+      console.warn(warning);
+    }
+  });
+
+  async function handleMessage(port, shimId, messageId, message) {
+    let response;
+    const shim = window.Shims.get(shimId);
+    if (shim) {
+      const { needsShimHelpers, origin } = shim;
+      if (origin === location.origin) {
+        if (needsShimHelpers?.includes(message)) {
+          const msg = { shimId, message };
+          try {
+            response = await browser.runtime.sendMessage(msg);
+          } catch (_) {}
+        }
+      }
+    }
+    port.postMessage({ messageId, response });
+  }
+
+  window.addEventListener(
+    "ShimConnects",
+    e => {
+      e.stopPropagation();
+      e.preventDefault();
+      const { port, pendingMessages, shimId } = e.detail;
+      const shim = window.Shims.get(shimId);
+      if (!shim) {
+        return;
+      }
+      port.onmessage = ({ data }) => {
+        handleMessage(port, shimId, data.messageId, data.message);
+      };
+      for (const [messageId, message] of pendingMessages) {
+        handleMessage(port, shimId, messageId, message);
+      }
+    },
+    true
+  );
+
+  window.dispatchEvent(new CustomEvent("ShimHelperReady"));
+}
diff --git a/browser/extensions/webcompat/lib/shims.js b/browser/extensions/webcompat/lib/shims.js
new file mode 100644
index 0000000000..ee33627c57
--- /dev/null
+++ b/browser/extensions/webcompat/lib/shims.js
@@ -0,0 +1,1044 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser, module, onMessageFromTab */
+
+// To grant shims access to bundled logo images without risking
+// exposing our moz-extension URL, we have the shim request them via
+// nonsense URLs which we then redirect to the actual files (but only
+// on tabs where a shim using a given logo happens to be active).
+const LogosBaseURL = "https://smartblock.firefox.etp/";
+
+const releaseBranchPromise = browser.appConstants.getReleaseBranch();
+
+const platformPromise = browser.runtime.getPlatformInfo().then(info => {
+  return info.os === "android" ? "android" : "desktop";
+});
+
+let debug = async function () {
+  if ((await releaseBranchPromise) !== "release_or_beta") {
+    console.debug.apply(this, arguments);
+  }
+};
+let error = async function () {
+  if ((await releaseBranchPromise) !== "release_or_beta") {
+    console.error.apply(this, arguments);
+  }
+};
+let warn = async function () {
+  if ((await releaseBranchPromise) !== "release_or_beta") {
+    console.warn.apply(this, arguments);
+  }
+};
+
+class Shim {
+  constructor(opts, manager) {
+    this.manager = manager;
+
+    const { contentScripts, matches, unblocksOnOptIn } = opts;
+
+    this.branches = opts.branches;
+    this.bug = opts.bug;
+    this.isGoogleTrendsDFPIFix = opts.custom == "google-trends-dfpi-fix";
+    this.file = opts.file;
+    this.hiddenInAboutCompat = opts.hiddenInAboutCompat;
+    this.hosts = opts.hosts;
+    this.id = opts.id;
+    this.logos = opts.logos || [];
+    this.matches = [];
+    this.name = opts.name;
+    this.notHosts = opts.notHosts;
+    this.onlyIfBlockedByETP = opts.onlyIfBlockedByETP;
+    this.onlyIfDFPIActive = opts.onlyIfDFPIActive;
+    this.onlyIfPrivateBrowsing = opts.onlyIfPrivateBrowsing;
+    this._options = opts.options || {};
+    this.needsShimHelpers = opts.needsShimHelpers;
+    this.platform = opts.platform || "all";
+    this.runFirst = opts.runFirst;
+    this.unblocksOnOptIn = unblocksOnOptIn;
+    this.requestStorageAccessForRedirect = opts.requestStorageAccessForRedirect;
+
+    this._hostOptIns = new Set();
+
+    this._disabledByConfig = opts.disabled;
+    this._disabledGlobally = false;
+    this._disabledForSession = false;
+    this._disabledByPlatform = false;
+    this._disabledByReleaseBranch = false;
+
+    this._activeOnTabs = new Set();
+    this._showedOptInOnTabs = new Set();
+
+    const pref = `disabled_shims.${this.id}`;
+
+    this.redirectsRequests = !!this.file && matches?.length;
+
+    this._contentScriptRegistrations = [];
+    this.contentScripts = contentScripts || [];
+    for (const script of this.contentScripts) {
+      if (typeof script.css === "string") {
+        script.css = [{ file: `/shims/${script.css}` }];
+      }
+      if (typeof script.js === "string") {
+        script.js = [{ file: `/shims/${script.js}` }];
+      }
+    }
+
+    for (const match of matches || []) {
+      if (!match.types) {
+        this.matches.push({ patterns: [match], types: ["script"] });
+      } else {
+        this.matches.push(match);
+      }
+      if (match.target) {
+        this.redirectsRequests = true;
+      }
+    }
+
+    browser.aboutConfigPrefs.onPrefChange.addListener(async () => {
+      const value = await browser.aboutConfigPrefs.getPref(pref);
+      this._disabledPrefValue = value;
+      this._onEnabledStateChanged();
+    }, pref);
+
+    this.ready = Promise.all([
+      browser.aboutConfigPrefs.getPref(pref),
+      platformPromise,
+      releaseBranchPromise,
+    ]).then(([disabledPrefValue, platform, branch]) => {
+      this._disabledPrefValue = disabledPrefValue;
+
+      this._disabledByPlatform =
+        this.platform !== "all" && this.platform !== platform;
+
+      this._disabledByReleaseBranch = false;
+      for (const supportedBranchAndPlatform of this.branches || []) {
+        const [supportedBranch, supportedPlatform] =
+          supportedBranchAndPlatform.split(":");
+        if (
+          (!supportedPlatform || supportedPlatform == platform) &&
+          supportedBranch != branch
+        ) {
+          this._disabledByReleaseBranch = true;
+        }
+      }
+
+      this._preprocessOptions(platform, branch);
+      this._onEnabledStateChanged();
+    });
+  }
+
+  _preprocessOptions(platform, branch) {
+    // options may be any value, but can optionally be gated for specified
+    // platform/branches, if in the format `{value, branches, platform}`
+    this.options = {};
+    for (const [k, v] of Object.entries(this._options)) {
+      if (v?.value) {
+        if (
+          (!v.platform || v.platform === platform) &&
+          (!v.branches || v.branches.includes(branch))
+        ) {
+          this.options[k] = v.value;
+        }
+      } else {
+        this.options[k] = v;
+      }
+    }
+  }
+
+  get enabled() {
+    if (this._disabledGlobally || this._disabledForSession) {
+      return false;
+    }
+
+    if (this._disabledPrefValue !== undefined) {
+      return !this._disabledPrefValue;
+    }
+
+    return (
+      !this._disabledByConfig &&
+      !this._disabledByPlatform &&
+      !this._disabledByReleaseBranch
+    );
+  }
+
+  get disabledReason() {
+    if (this._disabledGlobally) {
+      return "globalPref";
+    }
+
+    if (this._disabledForSession) {
+      return "session";
+    }
+
+    if (this._disabledPrefValue !== undefined) {
+      if (this._disabledPrefValue === true) {
+        return "pref";
+      }
+      return false;
+    }
+
+    if (this._disabledByConfig) {
+      return "config";
+    }
+
+    if (this._disabledByPlatform) {
+      return "platform";
+    }
+
+    if (this._disabledByReleaseBranch) {
+      return "releaseBranch";
+    }
+
+    return false;
+  }
+
+  onAllShimsEnabled() {
+    const wasEnabled = this.enabled;
+    this._disabledGlobally = false;
+    if (!wasEnabled) {
+      this._onEnabledStateChanged();
+    }
+  }
+
+  onAllShimsDisabled() {
+    const wasEnabled = this.enabled;
+    this._disabledGlobally = true;
+    if (wasEnabled) {
+      this._onEnabledStateChanged();
+    }
+  }
+
+  enableForSession() {
+    const wasEnabled = this.enabled;
+    this._disabledForSession = false;
+    if (!wasEnabled) {
+      this._onEnabledStateChanged();
+    }
+  }
+
+  disableForSession() {
+    const wasEnabled = this.enabled;
+    this._disabledForSession = true;
+    if (wasEnabled) {
+      this._onEnabledStateChanged();
+    }
+  }
+
+  async _onEnabledStateChanged() {
+    this.manager?.onShimStateChanged(this.id);
+    if (!this.enabled) {
+      await this._unregisterContentScripts();
+      return this._revokeRequestsInETP();
+    }
+    await this._registerContentScripts();
+    return this._allowRequestsInETP();
+  }
+
+  async _registerContentScripts() {
+    if (
+      this.contentScripts.length &&
+      !this._contentScriptRegistrations.length
+    ) {
+      const matches = [];
+      for (const options of this.contentScripts) {
+        matches.push(options.matches);
+        const reg = await browser.contentScripts.register(options);
+        this._contentScriptRegistrations.push(reg);
+      }
+      const urls = Array.from(new Set(matches.flat()));
+      debug("Enabling content scripts for these URLs:", urls);
+    }
+  }
+
+  async _unregisterContentScripts() {
+    for (const registration of this._contentScriptRegistrations) {
+      registration.unregister();
+    }
+    this._contentScriptRegistrations = [];
+  }
+
+  async _allowRequestsInETP() {
+    const matches = this.matches.map(m => m.patterns).flat();
+    if (matches.length) {
+      await browser.trackingProtection.shim(this.id, matches);
+    }
+
+    if (this._hostOptIns.size) {
+      const optIns = this.getApplicableOptIns();
+      if (optIns.length) {
+        await browser.trackingProtection.allow(
+          this.id,
+          this._optInPatterns,
+          Array.from(this._hostOptIns)
+        );
+      }
+    }
+  }
+
+  _revokeRequestsInETP() {
+    return browser.trackingProtection.revoke(this.id);
+  }
+
+  setActiveOnTab(tabId, active = true) {
+    if (active) {
+      this._activeOnTabs.add(tabId);
+    } else {
+      this._activeOnTabs.delete(tabId);
+      this._showedOptInOnTabs.delete(tabId);
+    }
+  }
+
+  isActiveOnTab(tabId) {
+    return this._activeOnTabs.has(tabId);
+  }
+
+  meantForHost(host) {
+    const { hosts, notHosts } = this;
+    if (hosts || notHosts) {
+      if (
+        (notHosts && notHosts.includes(host)) ||
+        (hosts && !hosts.includes(host))
+      ) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  async unblocksURLOnOptIn(url) {
+    if (!this._optInPatterns) {
+      this._optInPatterns = await this.getApplicableOptIns();
+    }
+
+    if (!this._optInMatcher) {
+      this._optInMatcher = browser.matchPatterns.getMatcher(
+        Array.from(this._optInPatterns)
+      );
+    }
+
+    return this._optInMatcher.matches(url);
+  }
+
+  isTriggeredByURLAndType(url, type) {
+    for (const entry of this.matches || []) {
+      if (!entry.types.includes(type)) {
+        continue;
+      }
+      if (!entry.matcher) {
+        entry.matcher = browser.matchPatterns.getMatcher(
+          Array.from(entry.patterns)
+        );
+      }
+      if (entry.matcher.matches(url)) {
+        return entry;
+      }
+    }
+
+    return undefined;
+  }
+
+  async getApplicableOptIns() {
+    if (this._applicableOptIns) {
+      return this._applicableOptIns;
+    }
+    const optins = [];
+    for (const unblock of this.unblocksOnOptIn || []) {
+      if (typeof unblock === "string") {
+        optins.push(unblock);
+        continue;
+      }
+      const { branches, patterns, platforms } = unblock;
+      if (platforms?.length) {
+        const platform = await platformPromise;
+        if (platform !== "all" && !platforms.includes(platform)) {
+          continue;
+        }
+      }
+      if (branches?.length) {
+        const branch = await releaseBranchPromise;
+        if (!branches.includes(branch)) {
+          continue;
+        }
+      }
+      optins.push.apply(optins, patterns);
+    }
+    this._applicableOptIns = optins;
+    return optins;
+  }
+
+  async onUserOptIn(host) {
+    const optins = await this.getApplicableOptIns();
+    if (optins.length) {
+      this.userHasOptedIn = true;
+      this._hostOptIns.add(host);
+      await browser.trackingProtection.allow(
+        this.id,
+        optins,
+        Array.from(this._hostOptIns)
+      );
+    }
+  }
+
+  hasUserOptedInAlready(host) {
+    return this._hostOptIns.has(host);
+  }
+
+  showOptInWarningOnce(tabId, origin) {
+    if (this._showedOptInOnTabs.has(tabId)) {
+      return Promise.resolve();
+    }
+    this._showedOptInOnTabs.add(tabId);
+
+    const { bug, name } = this;
+    const warning = `${name} is allowed on ${origin} for this browsing session due to user opt-in. See https://bugzilla.mozilla.org/show_bug.cgi?id=${bug} for details.`;
+    return browser.tabs
+      .executeScript(tabId, {
+        code: `console.warn(${JSON.stringify(warning)})`,
+        runAt: "document_start",
+      })
+      .catch(() => {});
+  }
+}
+
+class Shims {
+  constructor(availableShims) {
+    if (!browser.trackingProtection) {
+      console.error("Required experimental add-on APIs for shims unavailable");
+      return;
+    }
+
+    this._registerShims(availableShims);
+
+    onMessageFromTab(this._onMessageFromShim.bind(this));
+
+    this.ENABLED_PREF = "enable_shims";
+    browser.aboutConfigPrefs.onPrefChange.addListener(() => {
+      this._checkEnabledPref();
+    }, this.ENABLED_PREF);
+    this._haveCheckedEnabledPref = this._checkEnabledPref();
+  }
+
+  bindAboutCompatBroker(broker) {
+    this._aboutCompatBroker = broker;
+  }
+
+  getShimInfoForAboutCompat(shim) {
+    const { bug, disabledReason, hiddenInAboutCompat, id, name } = shim;
+    const type = "smartblock";
+    return { bug, disabledReason, hidden: hiddenInAboutCompat, id, name, type };
+  }
+
+  disableShimForSession(id) {
+    const shim = this.shims.get(id);
+    shim?.disableForSession();
+  }
+
+  enableShimForSession(id) {
+    const shim = this.shims.get(id);
+    shim?.enableForSession();
+  }
+
+  onShimStateChanged(id) {
+    if (!this._aboutCompatBroker) {
+      return;
+    }
+
+    const shim = this.shims.get(id);
+    if (!shim) {
+      return;
+    }
+
+    const shimsChanged = [this.getShimInfoForAboutCompat(shim)];
+    this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({ shimsChanged });
+  }
+
+  getAvailableShims() {
+    const shims = Array.from(this.shims.values()).map(
+      this.getShimInfoForAboutCompat
+    );
+    shims.sort((a, b) => a.name.localeCompare(b.name));
+    return shims;
+  }
+
+  _registerShims(shims) {
+    if (this.shims) {
+      throw new Error("_registerShims has already been called");
+    }
+
+    this.shims = new Map();
+    for (const shimOpts of shims) {
+      const { id } = shimOpts;
+      if (!this.shims.has(id)) {
+        this.shims.set(shimOpts.id, new Shim(shimOpts, this));
+      }
+    }
+
+    // Register onBeforeRequest listener which handles storage access requests
+    // on matching redirects.
+    let redirectTargetUrls = Array.from(shims.values())
+      .filter(shim => shim.requestStorageAccessForRedirect)
+      .flatMap(shim => shim.requestStorageAccessForRedirect)
+      .map(([, dstUrl]) => dstUrl);
+
+    // Unique target urls.
+    redirectTargetUrls = Array.from(new Set(redirectTargetUrls));
+
+    if (redirectTargetUrls.length) {
+      debug("Registering redirect listener for requestStorageAccess helper", {
+        redirectTargetUrls,
+      });
+      browser.webRequest.onBeforeRequest.addListener(
+        this._onRequestStorageAccessRedirect.bind(this),
+        { urls: redirectTargetUrls, types: ["main_frame"] },
+        ["blocking"]
+      );
+    }
+
+    function addTypePatterns(type, patterns, set) {
+      if (!set.has(type)) {
+        set.set(type, { patterns: new Set() });
+      }
+      const allSet = set.get(type).patterns;
+      for (const pattern of patterns) {
+        allSet.add(pattern);
+      }
+    }
+
+    const allMatchTypePatterns = new Map();
+    const allHeaderChangingMatchTypePatterns = new Map();
+    const allLogos = [];
+    for (const shim of this.shims.values()) {
+      const { logos, matches } = shim;
+      allLogos.push(...logos);
+      for (const { patterns, target, types } of matches || []) {
+        for (const type of types) {
+          if (shim.isGoogleTrendsDFPIFix) {
+            addTypePatterns(type, patterns, allHeaderChangingMatchTypePatterns);
+          }
+          if (target || shim.file || shim.runFirst) {
+            addTypePatterns(type, patterns, allMatchTypePatterns);
+          }
+        }
+      }
+    }
+
+    if (allLogos.length) {
+      const urls = Array.from(new Set(allLogos)).map(l => {
+        return `${LogosBaseURL}${l}`;
+      });
+      debug("Allowing access to these logos:", urls);
+      const unmarkShimsActive = tabId => {
+        for (const shim of this.shims.values()) {
+          shim.setActiveOnTab(tabId, false);
+        }
+      };
+      browser.tabs.onRemoved.addListener(unmarkShimsActive);
+      browser.tabs.onUpdated.addListener((tabId, changeInfo) => {
+        if (changeInfo.discarded || changeInfo.url) {
+          unmarkShimsActive(tabId);
+        }
+      });
+      browser.webRequest.onBeforeRequest.addListener(
+        this._redirectLogos.bind(this),
+        { urls, types: ["image"] },
+        ["blocking"]
+      );
+    }
+
+    if (allHeaderChangingMatchTypePatterns) {
+      for (const [
+        type,
+        { patterns },
+      ] of allHeaderChangingMatchTypePatterns.entries()) {
+        const urls = Array.from(patterns);
+        debug("Shimming these", type, "URLs:", urls);
+        browser.webRequest.onBeforeSendHeaders.addListener(
+          this._onBeforeSendHeaders.bind(this),
+          { urls, types: [type] },
+          ["blocking", "requestHeaders"]
+        );
+        browser.webRequest.onHeadersReceived.addListener(
+          this._onHeadersReceived.bind(this),
+          { urls, types: [type] },
+          ["blocking", "responseHeaders"]
+        );
+      }
+    }
+
+    if (!allMatchTypePatterns.size) {
+      debug("Skipping shims; none enabled");
+      return;
+    }
+
+    for (const [type, { patterns }] of allMatchTypePatterns.entries()) {
+      const urls = Array.from(patterns);
+      debug("Shimming these", type, "URLs:", urls);
+
+      browser.webRequest.onBeforeRequest.addListener(
+        this._ensureShimForRequestOnTab.bind(this),
+        { urls, types: [type] },
+        ["blocking"]
+      );
+    }
+  }
+
+  async _checkEnabledPref() {
+    await browser.aboutConfigPrefs.getPref(this.ENABLED_PREF).then(value => {
+      if (value === undefined) {
+        browser.aboutConfigPrefs.setPref(this.ENABLED_PREF, true);
+      } else if (value === false) {
+        this.enabled = false;
+      } else {
+        this.enabled = true;
+      }
+    });
+  }
+
+  get enabled() {
+    return this._enabled;
+  }
+
+  set enabled(enabled) {
+    if (enabled === this._enabled) {
+      return;
+    }
+
+    this._enabled = enabled;
+
+    for (const shim of this.shims.values()) {
+      if (enabled) {
+        shim.onAllShimsEnabled();
+      } else {
+        shim.onAllShimsDisabled();
+      }
+    }
+  }
+
+  async _onRequestStorageAccessRedirect({
+    originUrl: srcUrl,
+    url: dstUrl,
+    tabId,
+  }) {
+    debug("Detected redirect", { srcUrl, dstUrl, tabId });
+
+    // Check if a shim needs to request storage access for this redirect. This
+    // handler is called when the *source url* matches a shims redirect pattern,
+    // but we still need to check if the *destination url* matches.
+    const matchingShims = Array.from(this.shims.values()).filter(shim => {
+      const { enabled, requestStorageAccessForRedirect } = shim;
+
+      if (!enabled || !requestStorageAccessForRedirect) {
+        return false;
+      }
+
+      return requestStorageAccessForRedirect.some(
+        ([srcPattern, dstPattern]) =>
+          browser.matchPatterns.getMatcher([srcPattern]).matches(srcUrl) &&
+          browser.matchPatterns.getMatcher([dstPattern]).matches(dstUrl)
+      );
+    });
+
+    // For each matching shim, find out if its enabled in regard to dFPI state.
+    const bugNumbers = new Set();
+    let isDFPIActive = null;
+    await Promise.all(
+      matchingShims.map(async shim => {
+        if (shim.onlyIfDFPIActive) {
+          // Only get the dFPI state for the first shim which requires it.
+          if (isDFPIActive === null) {
+            const tabIsPB = (await browser.tabs.get(tabId)).incognito;
+            isDFPIActive = await browser.trackingProtection.isDFPIActive(
+              tabIsPB
+            );
+          }
+          if (!isDFPIActive) {
+            return;
+          }
+        }
+        bugNumbers.add(shim.bug);
+      })
+    );
+
+    // If there is no shim which needs storage access for this redirect src/dst
+    // pair, resume it.
+    if (!bugNumbers.size) {
+      return;
+    }
+
+    // Inject the helper to call requestStorageAccessForOrigin on the document.
+    await browser.tabs.executeScript(tabId, {
+      file: "/lib/requestStorageAccess_helper.js",
+      runAt: "document_start",
+    });
+
+    const bugUrls = Array.from(bugNumbers)
+      .map(bugNo => `https://bugzilla.mozilla.org/show_bug.cgi?id=${bugNo}`)
+      .join(", ");
+    const warning = `Firefox calls the Storage Access API for ${dstUrl} on behalf of ${srcUrl}. See the following bugs for details: ${bugUrls}`;
+
+    // Request storage access for the origin of the destination url of the
+    // redirect.
+    const { origin: requestStorageAccessOrigin } = new URL(dstUrl);
+
+    // Wait for the requestStorageAccess request to finish before resuming the
+    // redirect.
+    const { success } = await browser.tabs.sendMessage(tabId, {
+      requestStorageAccessOrigin,
+      warning,
+    });
+    debug("requestStorageAccess callback", {
+      success,
+      requestStorageAccessOrigin,
+      srcUrl,
+      dstUrl,
+      bugNumbers,
+    });
+  }
+
+  async _onMessageFromShim(payload, sender, sendResponse) {
+    const { tab, frameId } = sender;
+    const { id, url } = tab;
+    const { shimId, message } = payload;
+
+    // Ignore unknown messages (for instance, from about:compat).
+    if (message !== "getOptions" && message !== "optIn") {
+      return undefined;
+    }
+
+    if (sender.id !== browser.runtime.id || id === -1) {
+      throw new Error("not allowed");
+    }
+
+    // Important! It is entirely possible for sites to spoof
+    // these messages, due to shims allowing web pages to
+    // communicate with the extension.
+
+    const shim = this.shims.get(shimId);
+    if (!shim?.needsShimHelpers?.includes(message)) {
+      throw new Error("not allowed");
+    }
+
+    if (message === "getOptions") {
+      return Object.assign(
+        {
+          platform: await platformPromise,
+          releaseBranch: await releaseBranchPromise,
+        },
+        shim.options
+      );
+    } else if (message === "optIn") {
+      try {
+        await shim.onUserOptIn(new URL(url).hostname);
+        const origin = new URL(tab.url).origin;
+        warn(
+          "** User opted in for",
+          shim.name,
+          "shim on",
+          origin,
+          "on tab",
+          id,
+          "frame",
+          frameId
+        );
+        await shim.showOptInWarningOnce(id, origin);
+      } catch (err) {
+        console.error(err);
+        throw new Error("error");
+      }
+    }
+
+    return undefined;
+  }
+
+  async _redirectLogos(details) {
+    await this._haveCheckedEnabledPref;
+
+    if (!this.enabled) {
+      return { cancel: true };
+    }
+
+    const { tabId, url } = details;
+    const logo = new URL(url).pathname.slice(1);
+
+    for (const shim of this.shims.values()) {
+      await shim.ready;
+
+      if (!shim.enabled) {
+        continue;
+      }
+
+      if (shim.onlyIfDFPIActive) {
+        const isPB = (await browser.tabs.get(details.tabId)).incognito;
+        if (!(await browser.trackingProtection.isDFPIActive(isPB))) {
+          continue;
+        }
+      }
+
+      if (!shim.logos.includes(logo)) {
+        continue;
+      }
+
+      if (shim.isActiveOnTab(tabId)) {
+        return { redirectUrl: browser.runtime.getURL(`shims/${logo}`) };
+      }
+    }
+
+    return { cancel: true };
+  }
+
+  async _onHeadersReceived(details) {
+    await this._haveCheckedEnabledPref;
+
+    for (const shim of this.shims.values()) {
+      await shim.ready;
+
+      if (!shim.enabled) {
+        continue;
+      }
+
+      if (shim.onlyIfDFPIActive) {
+        const isPB = (await browser.tabs.get(details.tabId)).incognito;
+        if (!(await browser.trackingProtection.isDFPIActive(isPB))) {
+          continue;
+        }
+      }
+
+      if (shim.isGoogleTrendsDFPIFix) {
+        if (shim.GoogleNidCookieToUse) {
+          continue;
+        }
+
+        for (const header of details.responseHeaders) {
+          if (header.name == "set-cookie") {
+            shim.GoogleNidCookieToUse = header.value;
+            return { redirectUrl: details.url };
+          }
+        }
+      }
+    }
+
+    return undefined;
+  }
+
+  async _onBeforeSendHeaders(details) {
+    await this._haveCheckedEnabledPref;
+
+    const { frameId, requestHeaders, tabId } = details;
+
+    if (!this.enabled) {
+      return { requestHeaders };
+    }
+
+    for (const shim of this.shims.values()) {
+      await shim.ready;
+
+      if (!shim.enabled) {
+        continue;
+      }
+
+      if (shim.isGoogleTrendsDFPIFix) {
+        const value = shim.GoogleNidCookieToUse;
+
+        if (!value) {
+          continue;
+        }
+
+        let found;
+        for (let header of requestHeaders) {
+          if (header.name.toLowerCase() === "cookie") {
+            header.value = value;
+            found = true;
+          }
+        }
+        if (!found) {
+          requestHeaders.push({ name: "Cookie", value });
+        }
+
+        browser.tabs
+          .get(tabId)
+          .then(({ url }) => {
+            debug(
+              `Google Trends dFPI fix used on tab ${tabId} frame ${frameId} (${url})`
+            );
+          })
+          .catch(() => {});
+
+        const warning = `Working around Google Trends tracking protection breakage. See https://bugzilla.mozilla.org/show_bug.cgi?id=${shim.bug} for details.`;
+        browser.tabs
+          .executeScript(tabId, {
+            code: `console.warn(${JSON.stringify(warning)})`,
+            runAt: "document_start",
+          })
+          .catch(() => {});
+      }
+    }
+
+    return { requestHeaders };
+  }
+
+  async _ensureShimForRequestOnTab(details) {
+    await this._haveCheckedEnabledPref;
+
+    if (!this.enabled) {
+      return undefined;
+    }
+
+    // We only ever reach this point if a request is for a URL which ought to
+    // be shimmed. We never get here if a request is blocked, and we only
+    // unblock requests if at least one shim matches it.
+
+    const { frameId, originUrl, requestId, tabId, type, url } = details;
+
+    // Ignore requests unrelated to tabs
+    if (tabId < 0) {
+      return undefined;
+    }
+
+    // We need to base our checks not on the frame's host, but the tab's.
+    const topHost = new URL((await browser.tabs.get(tabId)).url).hostname;
+    const unblocked = await browser.trackingProtection.wasRequestUnblocked(
+      requestId
+    );
+
+    let match;
+    let shimToApply;
+    for (const shim of this.shims.values()) {
+      await shim.ready;
+
+      if (!shim.enabled || (!shim.redirectsRequests && !shim.runFirst)) {
+        continue;
+      }
+
+      if (shim.onlyIfDFPIActive || shim.onlyIfPrivateBrowsing) {
+        const isPB = (await browser.tabs.get(details.tabId)).incognito;
+        if (!isPB && shim.onlyIfPrivateBrowsing) {
+          continue;
+        }
+        if (
+          shim.onlyIfDFPIActive &&
+          !(await browser.trackingProtection.isDFPIActive(isPB))
+        ) {
+          continue;
+        }
+      }
+
+      // Do not apply the shim if it is only meant to apply when strict mode ETP
+      // (content blocking) was going to block the request.
+      if (!unblocked && shim.onlyIfBlockedByETP) {
+        continue;
+      }
+
+      if (!shim.meantForHost(topHost)) {
+        continue;
+      }
+
+      // If this URL and content type isn't meant for this shim, don't apply it.
+      match = shim.isTriggeredByURLAndType(url, type);
+      if (match) {
+        if (!unblocked && match.onlyIfBlockedByETP) {
+          continue;
+        }
+
+        // If the user has already opted in for this shim, all requests it covers
+        // should be allowed; no need for a shim anymore.
+        if (shim.hasUserOptedInAlready(topHost)) {
+          warn(
+            `Allowing tracking ${type} ${url} on tab ${tabId} frame ${frameId} due to opt-in`
+          );
+          shim.showOptInWarningOnce(tabId, new URL(originUrl).origin);
+          return undefined;
+        }
+        shimToApply = shim;
+        break;
+      }
+    }
+
+    let runFirst = false;
+
+    if (shimToApply) {
+      // Note that sites may request the same shim twice, but because the requests
+      // may differ enough for some to fail (CSP/CORS/etc), we always let the request
+      // complete via local redirect. Shims should gracefully handle this as well.
+
+      const { target } = match;
+      const { bug, file, id, name, needsShimHelpers } = shimToApply;
+      runFirst = shimToApply.runFirst;
+
+      const redirect = target || file;
+
+      warn(
+        `Shimming tracking ${type} ${url} on tab ${tabId} frame ${frameId} with ${
+          redirect || runFirst
+        }`
+      );
+
+      const warning = `${name} is being shimmed by Firefox. See https://bugzilla.mozilla.org/show_bug.cgi?id=${bug} for details.`;
+
+      let needConsoleMessage = true;
+
+      if (runFirst) {
+        try {
+          await browser.tabs.executeScript(tabId, {
+            file: `/shims/${runFirst}`,
+            frameId,
+            runAt: "document_start",
+          });
+        } catch (_) {}
+      }
+
+      // For scripts, we also set up any needed shim helpers.
+      if (type === "script" && needsShimHelpers?.length) {
+        try {
+          await browser.tabs.executeScript(tabId, {
+            file: "/lib/shim_messaging_helper.js",
+            frameId,
+            runAt: "document_start",
+          });
+          const origin = new URL(originUrl).origin;
+          await browser.tabs.sendMessage(
+            tabId,
+            { origin, shimId: id, needsShimHelpers, warning },
+            { frameId }
+          );
+          needConsoleMessage = false;
+          shimToApply.setActiveOnTab(tabId);
+        } catch (_) {}
+      }
+
+      if (needConsoleMessage) {
+        try {
+          await browser.tabs.executeScript(tabId, {
+            code: `console.warn(${JSON.stringify(warning)})`,
+            runAt: "document_start",
+          });
+        } catch (_) {}
+      }
+
+      if (!redirect.indexOf("http://") || !redirect.indexOf("https://")) {
+        return { redirectUrl: redirect };
+      }
+
+      // If any shims matched the request to replace it, then redirect to the local
+      // file bundled with SmartBlock, so the request never hits the network.
+      return { redirectUrl: browser.runtime.getURL(`shims/${redirect}`) };
+    }
+
+    // Sanity check: if no shims end up handling this request,
+    // yet it was meant to be blocked by ETP, then block it now.
+    if (unblocked) {
+      error(`unexpected: ${url} not shimmed on tab ${tabId} frame ${frameId}`);
+      return { cancel: true };
+    }
+
+    if (!runFirst) {
+      debug(`ignoring ${url} on tab ${tabId} frame ${frameId}`);
+    }
+    return undefined;
+  }
+}
+
+module.exports = Shims;
diff --git a/browser/extensions/webcompat/lib/ua_helpers.js b/browser/extensions/webcompat/lib/ua_helpers.js
new file mode 100644
index 0000000000..e2ab29c628
--- /dev/null
+++ b/browser/extensions/webcompat/lib/ua_helpers.js
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals exportFunction, module */
+
+var UAHelpers = {
+  _deviceAppropriateChromeUAs: {},
+  getDeviceAppropriateChromeUA(config = {}) {
+    const { version = "103.0.5060.71", androidDevice, desktopOS } = config;
+    const key = `${version}:${androidDevice}:${desktopOS}`;
+    if (!UAHelpers._deviceAppropriateChromeUAs[key]) {
+      const userAgent =
+        typeof navigator !== "undefined" ? navigator.userAgent : "";
+      const RunningFirefoxVersion = (userAgent.match(/Firefox\/([0-9.]+)/) || [
+        "",
+        "58.0",
+      ])[1];
+
+      if (userAgent.includes("Android")) {
+        const RunningAndroidVersion =
+          userAgent.match(/Android [0-9.]+/) || "Android 6.0";
+        if (androidDevice) {
+          UAHelpers._deviceAppropriateChromeUAs[
+            key
+          ] = `Mozilla/5.0 (Linux; ${RunningAndroidVersion}; ${androidDevice}) FxQuantum/${RunningFirefoxVersion} AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${version} Mobile Safari/537.36`;
+        } else {
+          const ChromePhoneUA = `Mozilla/5.0 (Linux; ${RunningAndroidVersion}; Nexus 5 Build/MRA58N) FxQuantum/${RunningFirefoxVersion} AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${version} Mobile Safari/537.36`;
+          const ChromeTabletUA = `Mozilla/5.0 (Linux; ${RunningAndroidVersion}; Nexus 7 Build/JSS15Q) FxQuantum/${RunningFirefoxVersion} AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${version} Safari/537.36`;
+          const IsPhone = userAgent.includes("Mobile");
+          UAHelpers._deviceAppropriateChromeUAs[key] = IsPhone
+            ? ChromePhoneUA
+            : ChromeTabletUA;
+        }
+      } else {
+        let osSegment = "Windows NT 10.0; Win64; x64";
+        if (desktopOS === "macOS" || userAgent.includes("Macintosh")) {
+          osSegment = "Macintosh; Intel Mac OS X 10_15_7";
+        }
+        if (
+          desktopOS !== "nonLinux" &&
+          (desktopOS === "linux" || userAgent.includes("Linux"))
+        ) {
+          osSegment = "X11; Ubuntu; Linux x86_64";
+        }
+
+        UAHelpers._deviceAppropriateChromeUAs[
+          key
+        ] = `Mozilla/5.0 (${osSegment}) FxQuantum/${RunningFirefoxVersion} AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${version} Safari/537.36`;
+      }
+    }
+    return UAHelpers._deviceAppropriateChromeUAs[key];
+  },
+  getPrefix(originalUA) {
+    return originalUA.substr(0, originalUA.indexOf(")") + 1);
+  },
+  overrideWithDeviceAppropriateChromeUA(config) {
+    const chromeUA = UAHelpers.getDeviceAppropriateChromeUA(config);
+    Object.defineProperty(window.navigator.wrappedJSObject, "userAgent", {
+      get: exportFunction(() => chromeUA, window),
+      set: exportFunction(function () {}, window),
+    });
+  },
+  capVersionTo99(originalUA) {
+    const ver = originalUA.match(/Firefox\/(\d+\.\d+)/);
+    if (!ver || parseFloat(ver[1]) < 100) {
+      return originalUA;
+    }
+    return originalUA
+      .replace(`Firefox/${ver[1]}`, "Firefox/99.0")
+      .replace(`rv:${ver[1]}`, "rv:99.0");
+  },
+};
+
+if (typeof module !== "undefined") {
+  module.exports = UAHelpers;
+}
diff --git a/browser/extensions/webcompat/lib/ua_overrides.js b/browser/extensions/webcompat/lib/ua_overrides.js
new file mode 100644
index 0000000000..2426293f3f
--- /dev/null
+++ b/browser/extensions/webcompat/lib/ua_overrides.js
@@ -0,0 +1,210 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser, module */
+
+class UAOverrides {
+  constructor(availableOverrides) {
+    this.OVERRIDE_PREF = "perform_ua_overrides";
+
+    this._overridesEnabled = true;
+
+    this._availableOverrides = availableOverrides;
+    this._activeListeners = new Map();
+  }
+
+  bindAboutCompatBroker(broker) {
+    this._aboutCompatBroker = broker;
+  }
+
+  bootup() {
+    browser.aboutConfigPrefs.onPrefChange.addListener(() => {
+      this.checkOverridePref();
+    }, this.OVERRIDE_PREF);
+    this.checkOverridePref();
+  }
+
+  checkOverridePref() {
+    browser.aboutConfigPrefs.getPref(this.OVERRIDE_PREF).then(value => {
+      if (value === undefined) {
+        browser.aboutConfigPrefs.setPref(this.OVERRIDE_PREF, true);
+      } else if (value === false) {
+        this.unregisterUAOverrides();
+      } else {
+        this.registerUAOverrides();
+      }
+    });
+  }
+
+  getAvailableOverrides() {
+    return this._availableOverrides;
+  }
+
+  isEnabled() {
+    return this._overridesEnabled;
+  }
+
+  enableOverride(override) {
+    if (override.active) {
+      return;
+    }
+
+    const { blocks, matches, uaTransformer } = override.config;
+    const listener = details => {
+      // Don't actually override the UA for an experiment if the user is not
+      // part of the experiment (unless they force-enabed the override).
+      if (
+        !override.config.experiment ||
+        override.permanentPrefEnabled === true
+      ) {
+        for (const header of details.requestHeaders) {
+          if (header.name.toLowerCase() === "user-agent") {
+            // Don't override the UA if we're on a mobile device that has the
+            // "Request Desktop Site" mode enabled. The UA for the desktop mode
+            // is set inside Gecko with a simple string replace, so we can use
+            // that as a check, see https://searchfox.org/mozilla-central/rev/89d33e1c3b0a57a9377b4815c2f4b58d933b7c32/mobile/android/chrome/geckoview/GeckoViewSettingsChild.js#23-28
+            let isMobileWithDesktopMode =
+              override.currentPlatform == "android" &&
+              header.value.includes("X11; Linux x86_64");
+
+            if (!isMobileWithDesktopMode) {
+              header.value = uaTransformer(header.value);
+            }
+          }
+        }
+      }
+      return { requestHeaders: details.requestHeaders };
+    };
+
+    browser.webRequest.onBeforeSendHeaders.addListener(
+      listener,
+      { urls: matches },
+      ["blocking", "requestHeaders"]
+    );
+
+    const listeners = { onBeforeSendHeaders: listener };
+    if (blocks) {
+      const blistener = details => {
+        return { cancel: true };
+      };
+
+      browser.webRequest.onBeforeRequest.addListener(
+        blistener,
+        { urls: blocks },
+        ["blocking"]
+      );
+
+      listeners.onBeforeRequest = blistener;
+    }
+    this._activeListeners.set(override, listeners);
+    override.active = true;
+  }
+
+  onOverrideConfigChanged(override) {
+    // Check whether the override should be hidden from about:compat.
+    override.hidden = override.config.hidden;
+
+    // Setting the override's permanent pref overrules whether it is hidden.
+    if (override.permanentPrefEnabled !== undefined) {
+      override.hidden = !override.permanentPrefEnabled;
+    }
+
+    // Also check whether the override should be active.
+    let shouldBeActive = true;
+
+    // Overrides can be force-deactivated by their permanent preference.
+    if (override.permanentPrefEnabled === false) {
+      shouldBeActive = false;
+    }
+
+    // Overrides gated behind an experiment the user is not part of do not
+    // have to be activated, unless they are gathering telemetry, or the
+    // user has force-enabled them with their permanent pref.
+    if (override.config.experiment && override.permanentPrefEnabled !== true) {
+      shouldBeActive = false;
+    }
+
+    if (shouldBeActive) {
+      this.enableOverride(override);
+    } else {
+      this.disableOverride(override);
+    }
+
+    if (this._overridesEnabled) {
+      this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
+        overridesChanged: this._aboutCompatBroker.filterOverrides(
+          this._availableOverrides
+        ),
+      });
+    }
+  }
+
+  async registerUAOverrides() {
+    const platformMatches = ["all"];
+    let platformInfo = await browser.runtime.getPlatformInfo();
+    platformMatches.push(platformInfo.os == "android" ? "android" : "desktop");
+
+    for (const override of this._availableOverrides) {
+      if (platformMatches.includes(override.platform)) {
+        override.availableOnPlatform = true;
+        override.currentPlatform = platformInfo.os;
+
+        // If there is a specific about:config preference governing
+        // this override, monitor its state.
+        const pref = override.config.permanentPref;
+        override.permanentPrefEnabled =
+          pref && (await browser.aboutConfigPrefs.getPref(pref));
+        if (pref) {
+          const checkOverridePref = () => {
+            browser.aboutConfigPrefs.getPref(pref).then(value => {
+              override.permanentPrefEnabled = value;
+              this.onOverrideConfigChanged(override);
+            });
+          };
+          browser.aboutConfigPrefs.onPrefChange.addListener(
+            checkOverridePref,
+            pref
+          );
+        }
+
+        this.onOverrideConfigChanged(override);
+      }
+    }
+
+    this._overridesEnabled = true;
+    this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
+      overridesChanged: this._aboutCompatBroker.filterOverrides(
+        this._availableOverrides
+      ),
+    });
+  }
+
+  unregisterUAOverrides() {
+    for (const override of this._availableOverrides) {
+      this.disableOverride(override);
+    }
+
+    this._overridesEnabled = false;
+    this._aboutCompatBroker.portsToAboutCompatTabs.broadcast({
+      overridesChanged: false,
+    });
+  }
+
+  disableOverride(override) {
+    if (!override.active) {
+      return;
+    }
+
+    const listeners = this._activeListeners.get(override);
+    for (const [name, listener] of Object.entries(listeners)) {
+      browser.webRequest[name].removeListener(listener);
+    }
+    override.active = false;
+    this._activeListeners.delete(override);
+  }
+}
+
+module.exports = UAOverrides;
diff --git a/browser/extensions/webcompat/manifest.json b/browser/extensions/webcompat/manifest.json
new file mode 100644
index 0000000000..c4a2592f3d
--- /dev/null
+++ b/browser/extensions/webcompat/manifest.json
@@ -0,0 +1,153 @@
+{
+  "manifest_version": 2,
+  "name": "Web Compatibility Interventions",
+  "description": "Urgent post-release fixes for web compatibility.",
+  "version": "115.1.0",
+  "browser_specific_settings": {
+    "gecko": {
+      "id": "webcompat@mozilla.org",
+      "strict_min_version": "102.0"
+    }
+  },
+
+  "experiment_apis": {
+    "aboutConfigPrefs": {
+      "schema": "experiment-apis/aboutConfigPrefs.json",
+      "parent": {
+        "scopes": ["addon_parent"],
+        "script": "experiment-apis/aboutConfigPrefs.js",
+        "paths": [["aboutConfigPrefs"]]
+      }
+    },
+    "appConstants": {
+      "schema": "experiment-apis/appConstants.json",
+      "parent": {
+        "scopes": ["addon_parent"],
+        "script": "experiment-apis/appConstants.js",
+        "paths": [["appConstants"]]
+      }
+    },
+    "aboutPage": {
+      "schema": "about-compat/aboutPage.json",
+      "parent": {
+        "scopes": ["addon_parent"],
+        "script": "about-compat/aboutPage.js",
+        "events": ["startup"]
+      }
+    },
+    "matchPatterns": {
+      "schema": "experiment-apis/matchPatterns.json",
+      "child": {
+        "scopes": ["addon_child"],
+        "script": "experiment-apis/matchPatterns.js",
+        "paths": [["matchPatterns"]]
+      }
+    },
+    "systemManufacturer": {
+      "schema": "experiment-apis/systemManufacturer.json",
+      "child": {
+        "scopes": ["addon_child"],
+        "script": "experiment-apis/systemManufacturer.js",
+        "paths": [["systemManufacturer"]]
+      }
+    },
+    "trackingProtection": {
+      "schema": "experiment-apis/trackingProtection.json",
+      "parent": {
+        "scopes": ["addon_parent"],
+        "script": "experiment-apis/trackingProtection.js",
+        "paths": [["trackingProtection"]]
+      }
+    }
+  },
+
+  "content_security_policy": "script-src 'self' 'sha256-PeZc2H1vv7M8NXqlFyNbN4y4oM6wXmYEbf73m+Aqpak='; default-src 'self'; base-uri moz-extension://*; object-src 'none'",
+
+  "permissions": [
+    "mozillaAddons",
+    "tabs",
+    "webNavigation",
+    "webRequest",
+    "webRequestBlocking",
+    "<all_urls>"
+  ],
+
+  "background": {
+    "scripts": [
+      "lib/module_shim.js",
+      "lib/messaging_helper.js",
+      "lib/intervention_helpers.js",
+      "lib/requestStorageAccess_helper.js",
+      "lib/ua_helpers.js",
+      "data/injections.js",
+      "data/shims.js",
+      "data/ua_overrides.js",
+      "lib/about_compat_broker.js",
+      "lib/custom_functions.js",
+      "lib/injections.js",
+      "lib/shims.js",
+      "lib/ua_overrides.js",
+      "run.js"
+    ]
+  },
+
+  "web_accessible_resources": [
+    "shims/addthis-angular.js",
+    "shims/adform.js",
+    "shims/adnexus-ast.js",
+    "shims/adnexus-prebid.js",
+    "shims/adsafeprotected-ima.js",
+    "shims/apstag.js",
+    "shims/blogger.js",
+    "shims/bloggerAccount.js",
+    "shims/bmauth.js",
+    "shims/branch.js",
+    "shims/chartbeat.js",
+    "shims/crave-ca.js",
+    "shims/criteo.js",
+    "shims/cxense.js",
+    "shims/doubleverify.js",
+    "shims/eluminate.js",
+    "shims/empty-script.js",
+    "shims/empty-shim.txt",
+    "shims/everest.js",
+    "shims/facebook-sdk.js",
+    "shims/facebook.svg",
+    "shims/fastclick.js",
+    "shims/firebase.js",
+    "shims/google-ads.js",
+    "shims/google-analytics-and-tag-manager.js",
+    "shims/google-analytics-ecommerce-plugin.js",
+    "shims/google-analytics-legacy.js",
+    "shims/google-ima.js",
+    "shims/google-page-ad.js",
+    "shims/google-publisher-tags.js",
+    "shims/google-safeframe.html",
+    "shims/history.js",
+    "shims/iam.js",
+    "shims/iaspet.js",
+    "shims/instagram.js",
+    "shims/kinja.js",
+    "shims/live-test-shim.js",
+    "shims/maxmind-geoip.js",
+    "shims/microsoftLogin.js",
+    "shims/microsoftVirtualAssistant.js",
+    "shims/moat.js",
+    "shims/mochitest-shim-1.js",
+    "shims/mochitest-shim-2.js",
+    "shims/mochitest-shim-3.js",
+    "shims/nielsen.js",
+    "shims/optimizely.js",
+    "shims/play.svg",
+    "shims/private-browsing-web-api-fixes.js",
+    "shims/rambler-authenticator.js",
+    "shims/rich-relevance.js",
+    "shims/spotify-embed.js",
+    "shims/tracking-pixel.png",
+    "shims/vast2.xml",
+    "shims/vast3.xml",
+    "shims/vidible.js",
+    "shims/vmad.xml",
+    "shims/webtrends.js"
+  ]
+}
diff --git a/browser/extensions/webcompat/moz.build b/browser/extensions/webcompat/moz.build
new file mode 100644
index 0000000000..0a75a15c90
--- /dev/null
+++ b/browser/extensions/webcompat/moz.build
@@ -0,0 +1,192 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DEFINES["MOZ_APP_VERSION"] = CONFIG["MOZ_APP_VERSION"]
+DEFINES["MOZ_APP_MAXVERSION"] = CONFIG["MOZ_APP_MAXVERSION"]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"] += [
+    "manifest.json",
+    "run.js",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["about-compat"] += [
+    "about-compat/aboutCompat.css",
+    "about-compat/aboutCompat.html",
+    "about-compat/aboutCompat.js",
+    "about-compat/AboutCompat.jsm",
+    "about-compat/aboutPage.js",
+    "about-compat/aboutPage.json",
+    "about-compat/aboutPageProcessScript.js",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["data"] += [
+    "data/injections.js",
+    "data/shims.js",
+    "data/ua_overrides.js",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["experiment-apis"] += [
+    "experiment-apis/aboutConfigPrefs.js",
+    "experiment-apis/aboutConfigPrefs.json",
+    "experiment-apis/appConstants.js",
+    "experiment-apis/appConstants.json",
+    "experiment-apis/matchPatterns.js",
+    "experiment-apis/matchPatterns.json",
+    "experiment-apis/systemManufacturer.js",
+    "experiment-apis/systemManufacturer.json",
+    "experiment-apis/trackingProtection.js",
+    "experiment-apis/trackingProtection.json",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["injections"]["css"] += [
+    "injections/css/bug0000000-testbed-css-injection.css",
+    "injections/css/bug1570328-developer-apple.com-transform-scale.css",
+    "injections/css/bug1575000-apply.lloydsbank.co.uk-radio-buttons-fix.css",
+    "injections/css/bug1605611-maps.google.com-directions-time.css",
+    "injections/css/bug1610344-directv.com.co-hide-unsupported-message.css",
+    "injections/css/bug1644830-missingmail.usps.com-checkboxes-not-visible.css",
+    "injections/css/bug1651917-teletrader.com.body-transform-origin.css",
+    "injections/css/bug1653075-livescience.com-scrollbar-width.css",
+    "injections/css/bug1654877-preev.com-moz-appearance-fix.css",
+    "injections/css/bug1654907-reactine.ca-hide-unsupported.css",
+    "injections/css/bug1694470-myvidster.com-content-not-shown.css",
+    "injections/css/bug1707795-office365-sheets-overscroll-disable.css",
+    "injections/css/bug1712833-buskocchi.desuca.co.jp-fix-map-height.css",
+    "injections/css/bug1741234-patient.alphalabs.ca-height-fix.css",
+    "injections/css/bug1765947-veniceincoming.com-left-fix.css",
+    "injections/css/bug1770962-coldwellbankerhomes.com-image-height.css",
+    "injections/css/bug1774490-rainews.it-gallery-fix.css",
+    "injections/css/bug1784141-aveeno.com-acuvue.com-unsupported.css",
+    "injections/css/bug1784199-entrata-platform-unsupported.css",
+    "injections/css/bug1799994-www.vivobarefoot.com-product-filters-fix.css",
+    "injections/css/bug1800000-www.honda.co.uk-choose-dealer-button-fix.css",
+    "injections/css/bug1819678-nppes.cms.hhs.gov-unsupported-banner.css",
+    "injections/css/bug1829949-tomshardware.com-scrollbar-width.css",
+    "injections/css/bug1829952-eventer.co.il-button-height.css",
+    "injections/css/bug1830747-babbel.com-page-height.css",
+    "injections/css/bug1830752-afisha.ru-slider-pointer-events.css",
+    "injections/css/bug1830761-91mobiles.com-content-height.css",
+    "injections/css/bug1830796-copyleaks.com-hide-unsupported.css",
+    "injections/css/bug1830810-interceramic.com-hide-unsupported.css",
+    "injections/css/bug1830813-page.onstove.com-hide-unsupported.css",
+    "injections/css/bug1836103-autostar-novoross.ru-make-map-taller.css",
+    "injections/css/bug1836105-cnn.com-fix-blank-pages-when-printing.css",
+    "injections/css/bug1836177-clalit.co.il-hide-number-input-spinners.css",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["injections"]["js"] += [
+    "injections/js/bug0000000-testbed-js-injection.js",
+    "injections/js/bug1448747-fastclick-shim.js",
+    "injections/js/bug1452707-window.controllers-shim-ib.absa.co.za.js",
+    "injections/js/bug1457335-histography.io-ua-change.js",
+    "injections/js/bug1472075-bankofamerica.com-ua-change.js",
+    "injections/js/bug1579159-m.tailieu.vn-pdfjs-worker-disable.js",
+    "injections/js/bug1605611-maps.google.com-directions-time.js",
+    "injections/js/bug1631811-datastudio.google.com-indexedDB.js",
+    "injections/js/bug1722955-frontgate.com-ua-override.js",
+    "injections/js/bug1724764-window-print.js",
+    "injections/js/bug1724868-news.yahoo.co.jp-ua-override.js",
+    "injections/js/bug1731825-office365-email-handling-prompt-autohide.js",
+    "injections/js/bug1739489-draftjs-beforeinput.js",
+    "injections/js/bug1769762-tiktok.com-plugins-shim.js",
+    "injections/js/bug1774005-installtrigger-shim.js",
+    "injections/js/bug1784302-effectiveType-shim.js",
+    "injections/js/bug1795490-www.china-airlines.com-undisable-date-fields-on-mobile.js",
+    "injections/js/bug1799968-www.samsung.com-appVersion-linux-fix.js",
+    "injections/js/bug1799980-healow.com-infinite-loop-fix.js",
+    "injections/js/bug1818818-fastclick-legacy-shim.js",
+    "injections/js/bug1819450-cmbchina.com-ua-change.js",
+    "injections/js/bug1819476-axisbank.com-webkitSpeechRecognition-shim.js",
+    "injections/js/bug1819678-cnki.net-undisable-search-field.js",
+    "injections/js/bug1819678-free4talk.com-window-chrome-shim.js",
+    "injections/js/bug1830776-blueshieldca.com-unsupported.js",
+    "injections/js/bug1831007-nintendo-window-OnetrustActiveGroups.js",
+    "injections/js/bug1836157-thai-masszazs-niceScroll-disable.js",
+    "injections/js/bug1842437-www.youtube.com-performance-now-precision.js",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["shims"] += [
+    "shims/addthis-angular.js",
+    "shims/adform.js",
+    "shims/adnexus-ast.js",
+    "shims/adnexus-prebid.js",
+    "shims/adsafeprotected-ima.js",
+    "shims/apstag.js",
+    "shims/blogger.js",
+    "shims/bloggerAccount.js",
+    "shims/bmauth.js",
+    "shims/branch.js",
+    "shims/chartbeat.js",
+    "shims/crave-ca.js",
+    "shims/criteo.js",
+    "shims/cxense.js",
+    "shims/doubleverify.js",
+    "shims/eluminate.js",
+    "shims/empty-script.js",
+    "shims/empty-shim.txt",
+    "shims/everest.js",
+    "shims/facebook-sdk.js",
+    "shims/facebook.svg",
+    "shims/fastclick.js",
+    "shims/firebase.js",
+    "shims/google-ads.js",
+    "shims/google-analytics-and-tag-manager.js",
+    "shims/google-analytics-ecommerce-plugin.js",
+    "shims/google-analytics-legacy.js",
+    "shims/google-ima.js",
+    "shims/google-page-ad.js",
+    "shims/google-publisher-tags.js",
+    "shims/google-safeframe.html",
+    "shims/history.js",
+    "shims/iam.js",
+    "shims/iaspet.js",
+    "shims/instagram.js",
+    "shims/kinja.js",
+    "shims/live-test-shim.js",
+    "shims/maxmind-geoip.js",
+    "shims/microsoftLogin.js",
+    "shims/microsoftVirtualAssistant.js",
+    "shims/moat.js",
+    "shims/mochitest-shim-1.js",
+    "shims/mochitest-shim-2.js",
+    "shims/mochitest-shim-3.js",
+    "shims/nielsen.js",
+    "shims/optimizely.js",
+    "shims/play.svg",
+    "shims/private-browsing-web-api-fixes.js",
+    "shims/rambler-authenticator.js",
+    "shims/rich-relevance.js",
+    "shims/spotify-embed.js",
+    "shims/tracking-pixel.png",
+    "shims/vast2.xml",
+    "shims/vast3.xml",
+    "shims/vidible.js",
+    "shims/vmad.xml",
+    "shims/webtrends.js",
+]
+
+FINAL_TARGET_FILES.features["webcompat@mozilla.org"]["lib"] += [
+    "lib/about_compat_broker.js",
+    "lib/custom_functions.js",
+    "lib/injections.js",
+    "lib/intervention_helpers.js",
+    "lib/messaging_helper.js",
+    "lib/module_shim.js",
+    "lib/requestStorageAccess_helper.js",
+    "lib/shim_messaging_helper.js",
+    "lib/shims.js",
+    "lib/ua_helpers.js",
+    "lib/ua_overrides.js",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+BROWSER_CHROME_MANIFESTS += ["tests/browser/browser.ini"]
+
+with Files("**"):
+    BUG_COMPONENT = ("Web Compatibility", "Tooling & Investigations")
diff --git a/browser/extensions/webcompat/run.js b/browser/extensions/webcompat/run.js
new file mode 100644
index 0000000000..5822dbb2ca
--- /dev/null
+++ b/browser/extensions/webcompat/run.js
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals AboutCompatBroker, AVAILABLE_INJECTIONS, AVAILABLE_SHIMS,
+           AVAILABLE_PIP_OVERRIDES, AVAILABLE_UA_OVERRIDES, CUSTOM_FUNCTIONS,
+           Injections, Shims, UAOverrides */
+
+let injections, shims, uaOverrides;
+
+try {
+  injections = new Injections(AVAILABLE_INJECTIONS, CUSTOM_FUNCTIONS);
+  injections.bootup();
+} catch (e) {
+  console.error("Injections failed to start", e);
+  injections = undefined;
+}
+
+try {
+  uaOverrides = new UAOverrides(AVAILABLE_UA_OVERRIDES);
+  uaOverrides.bootup();
+} catch (e) {
+  console.error("UA overrides failed to start", e);
+  uaOverrides = undefined;
+}
+
+try {
+  shims = new Shims(AVAILABLE_SHIMS);
+} catch (e) {
+  console.error("Shims failed to start", e);
+  shims = undefined;
+}
+
+try {
+  const aboutCompatBroker = new AboutCompatBroker({
+    injections,
+    shims,
+    uaOverrides,
+  });
+  aboutCompatBroker.bootup();
+} catch (e) {
+  console.error("about:compat broker failed to start", e);
+}
diff --git a/browser/extensions/webcompat/shims/addthis-angular.js b/browser/extensions/webcompat/shims/addthis-angular.js
new file mode 100644
index 0000000000..0f0cdd5029
--- /dev/null
+++ b/browser/extensions/webcompat/shims/addthis-angular.js
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713694 - Shim AddThis Angular module
+ *
+ * Sites using Angular with AddThis can break entirely if the module is
+ * blocked. This shim mitigates that breakage by loading an empty module.
+ */
+
+if (!window.addthisModule) {
+  window.addthisModule = window?.angular?.module("addthis", ["ng"]);
+}
diff --git a/browser/extensions/webcompat/shims/adform.js b/browser/extensions/webcompat/shims/adform.js
new file mode 100644
index 0000000000..d6727d500e
--- /dev/null
+++ b/browser/extensions/webcompat/shims/adform.js
@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713695 - Shim Adform tracking
+ *
+ * Sites such as m.tim.it may gate content behind AdForm's trackpoint,
+ * breaking download links and such if blocked. This shim stubs out the
+ * script and its related tracking pixel, so the content still works.
+ */
+
+if (!window.Adform) {
+  window.Adform = {
+    Opt: {
+      disableRedirect() {},
+      getStatus(clientID, callback) {
+        callback({
+          clientID,
+          errorMessage: undefined,
+          optIn() {},
+          optOut() {},
+          status: "nocookie",
+        });
+      },
+    },
+  };
+}
diff --git a/browser/extensions/webcompat/shims/adnexus-ast.js b/browser/extensions/webcompat/shims/adnexus-ast.js
new file mode 100644
index 0000000000..ae07fa6a03
--- /dev/null
+++ b/browser/extensions/webcompat/shims/adnexus-ast.js
@@ -0,0 +1,210 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1734130 - Shim AdNexus AST
+ *
+ * Some sites expect AST to successfully load, or they break.
+ * This shim mitigates that breakage.
+ */
+
+if (!window.apntag?.loaded) {
+  const anq = window.apntag?.anq || [];
+
+  const gTags = new Map();
+  const gAds = new Map();
+  const gEventHandlers = {};
+
+  const Ad = class {
+    adType = "banner";
+    auctionId = "-";
+    banner = {
+      width: 1,
+      height: 1,
+      content: "",
+      trackers: {
+        impression_urls: [],
+        video_events: {},
+      },
+    };
+    brandCategoryId = 0;
+    buyerMemberId = 0;
+    cpm = 0.1;
+    cpm_publisher_currency = 0.1;
+    creativeId = 0;
+    dealId = undefined;
+    height = 1;
+    mediaSubtypeId = 1;
+    mediaTypeId = 1;
+    publisher_currency_code = "US";
+    source = "-";
+    tagId = -1;
+    targetId = "";
+    width = 1;
+
+    constructor(tagId, targetId) {
+      this.tagId = tagId;
+      this.targetId = targetId;
+    }
+  };
+
+  const fireAdEvent = (type, adObj) => {
+    const { targetId } = adObj;
+    const handlers = gEventHandlers[type]?.[targetId];
+    if (!handlers) {
+      return Promise.resolve();
+    }
+    const evt = { adObj, type };
+    return new Promise(done => {
+      setTimeout(() => {
+        for (const cb of handlers) {
+          try {
+            cb(evt);
+          } catch (e) {
+            console.error(e);
+          }
+        }
+        done();
+      }, 1);
+    });
+  };
+
+  const refreshTag = targetId => {
+    const tag = gTags.get(targetId);
+    if (!tag) {
+      return;
+    }
+    if (!gAds.has(targetId)) {
+      gAds.set(targetId, new Ad(tag.tagId, targetId));
+    }
+    const adObj = gAds.get(targetId);
+    fireAdEvent("adRequested", adObj).then(() => {
+      // TODO: do some sites expect adAvailable+adLoaded instead of adNoBid?
+      fireAdEvent("adNoBid", adObj);
+    });
+  };
+
+  const off = (type, targetId, cb) => {
+    gEventHandlers[type]?.[targetId]?.delete(cb);
+  };
+
+  const on = (type, targetId, cb) => {
+    gEventHandlers[type] = gEventHandlers[type] || {};
+    gEventHandlers[type][targetId] =
+      gEventHandlers[type][targetId] || new Set();
+    gEventHandlers[type][targetId].add(cb);
+  };
+
+  const Tag = class {
+    static #nextId = 0;
+    debug = undefined;
+    displayed = false;
+    initialHeight = 1;
+    initialWidth = 1;
+    keywords = {};
+    member = 0;
+    showTagCalled = false;
+    sizes = [];
+    targetId = "";
+    utCalled = true;
+    utDivId = "";
+    utiframeId = "";
+    uuid = "";
+
+    constructor(raw) {
+      const { keywords, sizes, targetId } = raw;
+      this.tagId = Tag.#nextId++;
+      this.keywords = keywords || {};
+      this.sizes = sizes || [];
+      this.targetId = targetId || "";
+    }
+    modifyTag() {}
+    off(type, cb) {
+      off(type, this.targetId, cb);
+    }
+    on(type, cb) {
+      on(type, this.targetId, cb);
+    }
+    setKeywords(kw) {
+      this.keywords = kw;
+    }
+  };
+
+  window.apntag = {
+    anq,
+    attachClickTrackers() {},
+    checkAdAvailable() {},
+    clearPageTargeting() {},
+    clearRequest() {},
+    collapseAd() {},
+    debug: false,
+    defineTag(dfn) {
+      const { targetId } = dfn;
+      if (!targetId) {
+        return;
+      }
+      gTags.set(targetId, new Tag(dfn));
+    },
+    disableDebug() {},
+    dongle: undefined,
+    emitEvent(adObj, type) {
+      fireAdEvent(type, adObj);
+    },
+    enableCookieSet() {},
+    enableDebug() {},
+    fireImpressionTrackers() {},
+    getAdMarkup: () => "",
+    getAdWrap() {},
+    getAstVersion: () => "0.49.0",
+    getPageTargeting() {},
+    getTag(targetId) {
+      return gTags.get(targetId);
+    },
+    handleCb() {},
+    handleMediationBid() {},
+    highlightAd() {},
+    loaded: true,
+    loadTags() {
+      for (const tagName of gTags.keys()) {
+        refreshTag(tagName);
+      }
+    },
+    modifyTag() {},
+    notify() {},
+    offEvent(type, target, cb) {
+      off(type, target, cb);
+    },
+    onEvent(type, target, cb) {
+      on(type, target, cb);
+    },
+    recordErrorEvent() {},
+    refresh() {},
+    registerRenderer() {},
+    requests: {},
+    resizeAd() {},
+    setEndpoint() {},
+    setKeywords() {},
+    setPageOpts() {},
+    setPageTargeting() {},
+    setSafeFrameConfig() {},
+    setSizes() {},
+    showTag() {},
+  };
+
+  const push = function (fn) {
+    if (typeof fn === "function") {
+      try {
+        fn();
+      } catch (e) {
+        console.trace(e);
+      }
+    }
+  };
+
+  anq.push = push;
+
+  anq.forEach(push);
+}
diff --git a/browser/extensions/webcompat/shims/adnexus-prebid.js b/browser/extensions/webcompat/shims/adnexus-prebid.js
new file mode 100644
index 0000000000..f0f810f0e9
--- /dev/null
+++ b/browser/extensions/webcompat/shims/adnexus-prebid.js
@@ -0,0 +1,68 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1694401 - Shim Prebid.js
+ *
+ * Some sites rely on prebid.js to place content, perhaps in conjunction with
+ * other services like Google Publisher Tags and Amazon TAM. This shim prevents
+ * site breakage like image galleries breaking as the user browsers them, by
+ * allowing the content placement to succeed.
+ */
+
+if (!window.pbjs?.requestBids) {
+  const que = window.pbjs?.que || [];
+  const cmd = window.pbjs?.cmd || [];
+  const adUnits = window.pbjs?.adUnits || [];
+
+  window.pbjs = {
+    adUnits,
+    addAdUnits(arr) {
+      if (!Array.isArray(arr)) {
+        arr = [arr];
+      }
+      adUnits.push(arr);
+    },
+    cmd,
+    offEvent() {},
+    que,
+    refreshAds() {},
+    removeAdUnit(codes) {
+      if (!Array.isArray(codes)) {
+        codes = [codes];
+      }
+      for (const code of codes) {
+        for (let i = adUnits.length - 1; i >= 0; i--) {
+          if (adUnits[i].code === code) {
+            adUnits.splice(i, 1);
+          }
+        }
+      }
+    },
+    renderAd() {},
+    requestBids(params) {
+      params?.bidsBackHandler?.();
+    },
+    setConfig() {},
+    setTargetingForGPTAsync() {},
+  };
+
+  const push = function (fn) {
+    if (typeof fn === "function") {
+      try {
+        fn();
+      } catch (e) {
+        console.trace(e);
+      }
+    }
+  };
+
+  que.push = push;
+  cmd.push = push;
+
+  que.forEach(push);
+  cmd.forEach(push);
+}
diff --git a/browser/extensions/webcompat/shims/adsafeprotected-ima.js b/browser/extensions/webcompat/shims/adsafeprotected-ima.js
new file mode 100644
index 0000000000..93cd8e1eab
--- /dev/null
+++ b/browser/extensions/webcompat/shims/adsafeprotected-ima.js
@@ -0,0 +1,19 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ *
+ * Sites relying on Ad Safe Protected's adapter for Google IMA may
+ * have broken videos when the script is blocked. This shim stubs
+ * out the API to help mitigate major breakage.
+ */
+
+if (!window.googleImaVansAdapter) {
+  window.googleImaVansAdapter = {
+    init() {},
+    dispose() {},
+  };
+}
diff --git a/browser/extensions/webcompat/shims/apstag.js b/browser/extensions/webcompat/shims/apstag.js
new file mode 100644
index 0000000000..55be05916b
--- /dev/null
+++ b/browser/extensions/webcompat/shims/apstag.js
@@ -0,0 +1,73 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713698 - Shim Amazon Transparent Ad Marketplace's apstag.js
+ *
+ * Some sites such as politico.com rely on Amazon TAM tracker to serve ads,
+ * breaking functionality like galleries if it is blocked. This shim helps
+ * mitigate major breakage in that case.
+ */
+
+if (!window.apstag?._getSlotIdToNameMapping) {
+  const _Q = window.apstag?._Q || [];
+
+  const newBid = config => {
+    return {
+      amznbid: "",
+      amzniid: "",
+      amznp: "",
+      amznsz: "0x0",
+      size: "0x0",
+      slotID: config.slotID,
+    };
+  };
+
+  window.apstag = {
+    _Q,
+    _getSlotIdToNameMapping() {},
+    bids() {},
+    debug() {},
+    deleteId() {},
+    fetchBids(cfg, cb) {
+      if (!Array.isArray(cfg?.slots)) {
+        return;
+      }
+      setTimeout(() => {
+        cb(cfg.slots.map(s => newBid(s)));
+      }, 1);
+    },
+    init() {},
+    punt() {},
+    renderImp() {},
+    renewId() {},
+    setDisplayBids() {},
+    targetingKeys: () => [],
+    thirdPartyData: {},
+    updateId() {},
+  };
+
+  window.apstagLOADED = true;
+
+  _Q.push = function (prefix, args) {
+    try {
+      switch (prefix) {
+        case "f":
+          window.apstag.fetchBids(...args);
+          break;
+        case "i":
+          window.apstag.init(...args);
+          break;
+      }
+    } catch (e) {
+      console.trace(e);
+    }
+  };
+
+  for (const cmd of _Q) {
+    _Q.push(cmd);
+  }
+}
diff --git a/browser/extensions/webcompat/shims/blogger.js b/browser/extensions/webcompat/shims/blogger.js
new file mode 100644
index 0000000000..a474b3c5e9
--- /dev/null
+++ b/browser/extensions/webcompat/shims/blogger.js
@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* globals exportFunction */
+
+"use strict";
+
+/**
+ * Blogger powered blogs rely on storage access to https://blogger.com to enable
+ * oauth with Google. For dFPI, sites need to use the Storage Access API to gain
+ * first party storage access. This shim calls requestStorageAccess on behalf of
+ * the site when a user wants to log in via oauth.
+ */
+
+console.warn(
+  `When using oauth, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1776869 for details.`
+);
+
+const GOOGLE_OAUTH_PATH_PREFIX = "https://accounts.google.com/ServiceLogin";
+
+// Overwrite the window.open method so we can detect oauth related popups.
+const origOpen = window.wrappedJSObject.open;
+Object.defineProperty(window.wrappedJSObject, "open", {
+  value: exportFunction((url, ...args) => {
+    // Filter oauth popups.
+    if (!url.startsWith(GOOGLE_OAUTH_PATH_PREFIX)) {
+      return origOpen(url, ...args);
+    }
+    // Request storage access for the Blogger iframe.
+    document.requestStorageAccess().then(() => {
+      origOpen(url, ...args);
+    });
+    // We don't have the window object yet which window.open returns, since the
+    // sign-in flow is dependent on the async storage access request. This isn't
+    // a problem as long as the website does not consume it.
+    return null;
+  }, window),
+});
diff --git a/browser/extensions/webcompat/shims/bloggerAccount.js b/browser/extensions/webcompat/shims/bloggerAccount.js
new file mode 100644
index 0000000000..19e80dbfbe
--- /dev/null
+++ b/browser/extensions/webcompat/shims/bloggerAccount.js
@@ -0,0 +1,68 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* globals exportFunction */
+
+"use strict";
+
+/**
+ * Blogger uses Google as the auth provider. The account panel uses a
+ * third-party iframe of https://ogs.google.com, which requires first-party
+ * storage access to authenticate. This shim calls requestStorageAccess on
+ * behalf of the site when the user opens the account panel.
+ */
+
+console.warn(
+  `When logging in with Google, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1777690 for details.`
+);
+
+const STORAGE_ACCESS_ORIGIN = "https://ogs.google.com";
+
+document.documentElement.addEventListener(
+  "click",
+  e => {
+    const { target, isTrusted } = e;
+    if (!isTrusted) {
+      return;
+    }
+
+    const anchorEl = target.closest("a");
+    if (!anchorEl) {
+      return;
+    }
+
+    if (
+      !anchorEl.href.startsWith("https://accounts.google.com/SignOutOptions")
+    ) {
+      return;
+    }
+
+    // The storage access request below runs async so the panel won't open
+    // immediately. Mitigate this UX issue by updating the clicked element's
+    // style so the user gets some immediate feedback.
+    anchorEl.style.opacity = 0.5;
+    e.stopPropagation();
+    e.preventDefault();
+
+    document
+      .requestStorageAccessForOrigin(STORAGE_ACCESS_ORIGIN)
+      .then(() => {
+        // Reload all iframes of ogs.google.com so the first-party cookies are
+        // sent to the server.
+        // The reload mechanism here is a bit of a hack, since we don't have
+        // access to the content window of a cross-origin iframe.
+        document
+          .querySelectorAll("iframe[src^='https://ogs.google.com/']")
+          .forEach(frame => (frame.src += ""));
+      })
+      // Show the panel in both success and error state. When the user denies
+      // the storage access prompt they will see an error message in the account
+      // panel.
+      .finally(() => {
+        anchorEl.style.opacity = 1.0;
+        target.click();
+      });
+  },
+  true
+);
diff --git a/browser/extensions/webcompat/shims/bmauth.js b/browser/extensions/webcompat/shims/bmauth.js
new file mode 100644
index 0000000000..944f2100d6
--- /dev/null
+++ b/browser/extensions/webcompat/shims/bmauth.js
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+if (!window.BmAuth) {
+  window.BmAuth = {
+    init: () => new Promise(() => {}),
+    handleSignIn: () => {
+      // TODO: handle this properly!
+    },
+    isAuthenticated: () => Promise.resolve(false),
+    addListener: () => {},
+    api: {
+      event: {
+        addListener: () => {},
+      },
+    },
+  };
+}
diff --git a/browser/extensions/webcompat/shims/branch.js b/browser/extensions/webcompat/shims/branch.js
new file mode 100644
index 0000000000..31e8f4eeec
--- /dev/null
+++ b/browser/extensions/webcompat/shims/branch.js
@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1716220 - Shim Branch Web SDK
+ *
+ * Sites such as TataPlay may not load properly if Branch Web SDK is
+ * blocked. This shim stubs out its script so the page still loads.
+ */
+
+if (!window?.branch?.b) {
+  const queue = window?.branch?._q || [];
+  window.branch = new (class {
+    V = {};
+    g = 0;
+    X = "web2.62.0";
+    b = {
+      A: {},
+      clear() {},
+      get() {},
+      getAll() {},
+      isEnabled: () => true,
+      remove() {},
+      set() {},
+      ca() {},
+      g: [],
+      l: 0,
+      o: 0,
+      s: null,
+    };
+    addListener() {}
+    applyCode() {}
+    autoAppIndex() {}
+    banner() {}
+    c() {}
+    closeBanner() {}
+    closeJourney() {}
+    constructor() {}
+    creditHistory() {}
+    credits() {}
+    crossPlatformIds() {}
+    data() {}
+    deepview() {}
+    deepviewCta() {}
+    disableTracking() {}
+    first() {}
+    getBrowserFingerprintId() {}
+    getCode() {}
+    init(key, ...args) {
+      const cb = args.pop();
+      if (typeof cb === "function") {
+        cb(undefined, {});
+      }
+    }
+    lastAttributedTouchData() {}
+    link() {}
+    logEvent() {}
+    logout() {}
+    qrCode() {}
+    redeem() {}
+    referrals() {}
+    removeListener() {}
+    renderFinalize() {}
+    renderQueue() {}
+    sendSMS() {}
+    setAPIResponseCallback() {}
+    setBranchViewData() {}
+    setIdentity() {}
+    track() {}
+    trackCommerceEvent() {}
+    validateCode() {}
+  })();
+  const push = ([fn, ...args]) => {
+    try {
+      window.branch[fn].apply(window.branch, args);
+    } catch (e) {
+      console.error(e);
+    }
+  };
+  queue.forEach(push);
+}
diff --git a/browser/extensions/webcompat/shims/chartbeat.js b/browser/extensions/webcompat/shims/chartbeat.js
new file mode 100644
index 0000000000..0e57fc6da1
--- /dev/null
+++ b/browser/extensions/webcompat/shims/chartbeat.js
@@ -0,0 +1,18 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713699 - Shim ChartBeat tracking
+ *
+ * Sites may rely on chartbeat's tracking as they might with Google Analytics,
+ * expecting it to be present for interactive site content to function. This
+ * shim mitigates related breakage.
+ */
+
+window.pSUPERFLY = {
+  activity() {},
+  virtualPage() {},
+};
diff --git a/browser/extensions/webcompat/shims/crave-ca.js b/browser/extensions/webcompat/shims/crave-ca.js
new file mode 100644
index 0000000000..b4d93ccdfa
--- /dev/null
+++ b/browser/extensions/webcompat/shims/crave-ca.js
@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/*
+ * Bug 1746439 - crave.ca login broken with dFPI enabled
+ *
+ * Crave.ca relies upon a login page that is out-of-origin. That login page
+ * sets a cookie for https://www.crave.ca, which is then used as an proof of
+ * authentication on redirect back to the main site. This shim adds a request
+ * for storage access for https://www.crave.ca when the user tries to log in.
+ */
+
+console.warn(
+  `When logging in, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1746439 for details.`
+);
+
+// Third-party origin we need to request storage access for.
+const STORAGE_ACCESS_ORIGIN = "https://www.crave.ca";
+
+document.documentElement.addEventListener(
+  "click",
+  e => {
+    const { target, isTrusted } = e;
+    if (!isTrusted) {
+      return;
+    }
+    const button = target.closest("button");
+    if (!button) {
+      return;
+    }
+    const form = target.closest(".login-form");
+    if (!form) {
+      return;
+    }
+
+    console.warn(
+      "Calling the Storage Access API on behalf of " + STORAGE_ACCESS_ORIGIN
+    );
+    button.disabled = true;
+    e.stopPropagation();
+    e.preventDefault();
+    document
+      .requestStorageAccessForOrigin(STORAGE_ACCESS_ORIGIN)
+      .then(() => {
+        button.disabled = false;
+        target.click();
+      })
+      .catch(() => {
+        button.disabled = false;
+      });
+  },
+  true
+);
diff --git a/browser/extensions/webcompat/shims/criteo.js b/browser/extensions/webcompat/shims/criteo.js
new file mode 100644
index 0000000000..afdc00b888
--- /dev/null
+++ b/browser/extensions/webcompat/shims/criteo.js
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713720 - Shim Criteo
+ *
+ * Sites relying on window.Criteo to be loaded can experience
+ * breakage if it is blocked. Stubbing out the API in a shim can
+ * mitigate this breakage.
+ */
+
+if (window.Criteo?.CallRTA === undefined) {
+  window.Criteo = {
+    CallRTA() {},
+    ComputeStandaloneDFPTargeting() {},
+    DisplayAcceptableAdIfAdblocked() {},
+    DisplayAd() {},
+    GetBids() {},
+    GetBidsForAdUnit() {},
+    Passback: {
+      RequestBids() {},
+      RenderAd() {},
+    },
+    PubTag: {
+      Adapters: {
+        AMP() {},
+        Prebid() {},
+      },
+      Context: {
+        GetIdfs() {},
+        SetIdfs() {},
+      },
+      DirectBidding: {
+        DirectBiddingEvent() {},
+        DirectBiddingSlot() {},
+        DirectBiddingUrlBuilder() {},
+        Size() {},
+      },
+      RTA: {
+        DefaultCrtgContentName: "crtg_content",
+        DefaultCrtgRtaCookieName: "crtg_rta",
+      },
+    },
+    RenderAd() {},
+    RequestBids() {},
+    RequestBidsOnGoogleTagSlots() {},
+    SetCCPAExplicitOptOut() {},
+    SetCeh() {},
+    SetDFPKeyValueTargeting() {},
+    SetLineItemRanges() {},
+    SetPublisherExt() {},
+    SetSlotsExt() {},
+    SetTargeting() {},
+    SetUserExt() {},
+    events: {
+      push() {},
+    },
+    passbackEvents: [],
+    usePrebidEvents: true,
+  };
+}
diff --git a/browser/extensions/webcompat/shims/cxense.js b/browser/extensions/webcompat/shims/cxense.js
new file mode 100644
index 0000000000..55862f4fb5
--- /dev/null
+++ b/browser/extensions/webcompat/shims/cxense.js
@@ -0,0 +1,593 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713721 - Shim Cxense
+ *
+ * Sites relying on window.cX can experience breakage if it is blocked.
+ * Stubbing out the API in a shim can mitigate this breakage. There are
+ * two versions of the API, one including window.cX.CCE, but both appear
+ * to be very similar so we use one shim for both.
+ */
+
+if (window.cX?.getUserSegmentIds === undefined) {
+  const callQueue = window.cX?.callQueue || [];
+  const callQueueCCE = window.cX?.CCE?.callQueue || [];
+
+  function getRandomString(l = 16) {
+    const v = crypto.getRandomValues(new Uint8Array(l));
+    const s = Array.from(v, c => c.toString(16)).join("");
+    return s.slice(0, l);
+  }
+
+  const call = (cb, ...args) => {
+    if (typeof cb !== "function") {
+      return;
+    }
+    try {
+      cb(...args);
+    } catch (e) {
+      console.error(e);
+    }
+  };
+
+  const invokeOn = lib => {
+    return (fn, ...args) => {
+      try {
+        lib[fn](...args);
+      } catch (e) {
+        console.error(e);
+      }
+    };
+  };
+
+  const userId = getRandomString();
+  const cxUserId = `cx:${getRandomString(25)}:${getRandomString(12)}`;
+  const topLeft = { left: 0, top: 0 };
+  const margins = { left: 0, top: 0, right: 0, bottom: 0 };
+  const ccePushUrl =
+    "https://comcluster.cxense.com/cce/push?callback={{callback}}";
+  const displayWidget = (divId, a, ctx, callback) => call(callback, ctx, divId);
+  const getUserSegmentIds = a => call(a?.callback, a?.defaultValue || []);
+  const init = (a, b, c, d, callback) => call(callback);
+  const render = (a, data, ctx, callback) => call(callback, data, ctx);
+  const run = (params, ctx, callback) => call(callback, params, ctx);
+  const runCtrlVersion = (a, b, callback) => call(callback);
+  const runCxVersion = (a, data, b, ctx, callback) => call(callback, data, ctx);
+  const runTest = (a, divId, b, c, ctx, callback) => call(callback, divId, ctx);
+  const sendConversionEvent = (a, options) => call(options?.callback, {});
+  const sendEvent = (a, b, args) => call(args?.callback, {});
+
+  const getDivId = className => {
+    const e = document.querySelector(`.${className}`);
+    if (e) {
+      return `${className}-01`;
+    }
+    return null;
+  };
+
+  const getDocumentSize = () => {
+    const width = document.body.clientWidth;
+    const height = document.body.clientHeight;
+    return { width, height };
+  };
+
+  const getNowSeconds = () => {
+    return Math.round(new Date().getTime() / 1000);
+  };
+
+  const getPageContext = () => {
+    return {
+      location: location.href,
+      pageViewRandom: "",
+      userId,
+    };
+  };
+
+  const getWindowSize = () => {
+    const width = window.innerWidth;
+    const height = window.innerHeight;
+    return { width, height };
+  };
+
+  const isObject = i => {
+    return typeof i === "object" && i !== null && !Array.isArray(i);
+  };
+
+  const runMulti = widgets => {
+    widgets?.forEach(({ widgetParams, widgetContext, widgetCallback }) => {
+      call(widgetCallback, widgetParams, widgetContext);
+    });
+  };
+
+  let testGroup = -1;
+  let snapPoints = [];
+  const startTime = new Date();
+
+  const library = {
+    addCustomerScript() {},
+    addEventListener() {},
+    addExternalId() {},
+    afterInitializePage() {},
+    allUserConsents() {},
+    backends: {
+      production: {
+        baseAdDeliveryUrl: "http://adserver.cxad.cxense.com/adserver/search",
+        secureBaseAdDeliveryUrl:
+          "https://s-adserver.cxad.cxense.com/adserver/search",
+      },
+      sandbox: {
+        baseAdDeliveryUrl:
+          "http://adserver.sandbox.cxad.cxense.com/adserver/search",
+        secureBaseAdDeliveryUrl:
+          "https://s-adserver.sandbox.cxad.cxense.com/adserver/search",
+      },
+    },
+    calculateAdSpaceSize(adCount, adUnitSize, marginA, marginB) {
+      return adCount * (adUnitSize + marginA + marginB);
+    },
+    cdn: {
+      template: {
+        direct: {
+          http: "http://cdn.cxpublic.com/",
+          https: "https://cdn.cxpublic.com/",
+        },
+        mapped: {
+          http: "http://cdn-templates.cxpublic.com/",
+          https: "https://cdn-templates.cxpublic.com/",
+        },
+      },
+    },
+    cint() {},
+    cleanUpGlobalIds: [],
+    clearBaseUrl: "https://scdn.cxense.com/sclear.html",
+    clearCustomParameters() {},
+    clearIdUrl: "https://scomcluster.cxense.com/public/clearid",
+    clearIds() {},
+    clickTracker: (a, b, callback) => call(callback),
+    clientStorageUrl: "https://clientstorage.cxense.com",
+    combineArgs: () => Object.create(),
+    combineKeywordsIntoArray: () => [],
+    consentClasses: ["pv", "segment", "ad", "recs"],
+    consentClassesV2: ["geo", "device"],
+    cookieSyncRUrl: "csyn-r.cxense.com",
+    createDelegate() {},
+    csdUrls: {
+      domainScriptUrl: "//csd.cxpublic.com/d/",
+      customerScriptUrl: "//csd.cxpublic.com/t/",
+    },
+    cxenseGlobalIdIframeUrl: "https://scdn.cxense.com/sglobal.html",
+    cxenseUserIdUrl: "https://id.cxense.com/public/user/id",
+    decodeUrlEncodedNameValuePairs: () => Object.create(),
+    defaultAdRenderer: () => "",
+    deleteCookie() {},
+    denyWithoutConsent: {
+      addExternalId: "pv",
+      getUserSegmentIds: "segment",
+      insertAdSpace: "ad",
+      insertMultipleAdSpaces: "ad",
+      sendEvent: "pv",
+      sendPageViewEvent: "pv",
+      sync: "ad",
+    },
+    dmpPushUrl: "https://comcluster.cxense.com/dmp/push?callback={{callback}}",
+    emptyWidgetUrl: "https://scdn.cxense.com/empty.html",
+    eventReceiverBaseUrl: "https://scomcluster.cxense.com/Repo/rep.html",
+    eventReceiverBaseUrlGif: "https://scomcluster.cxense.com/Repo/rep.gif",
+    getAllText: () => "",
+    getClientStorageVariable() {},
+    getCookie: () => null,
+    getCxenseUserId: () => cxUserId,
+    getDocumentSize,
+    getElementPosition: () => topLeft,
+    getHashFragment: () => location.hash.substr(1),
+    getLocalStats: () => Object.create(),
+    getNodeValue: n => n.nodeValue,
+    getNowSeconds,
+    getPageContext,
+    getRandomString,
+    getScrollPos: () => topLeft,
+    getSessionId: () => "",
+    getSiteId: () => "",
+    getTimezoneOffset: () => new Date().getTimezoneOffset(),
+    getTopLevelDomain: () => location.hostname,
+    getUserId: () => userId,
+    getUserSegmentIds,
+    getWindowSize,
+    hasConsent: () => true,
+    hasHistory: () => true,
+    hasLocalStorage: () => true,
+    hasPassiveEventListeners: () => true,
+    hasPostMessage: () => true,
+    hasSessionStorage() {},
+    initializePage() {},
+    insertAdSpace() {},
+    insertMultipleAdSpaces() {},
+    insertWidget() {},
+    invoke: invokeOn(library),
+    isAmpIFrame() {},
+    isArray() {},
+    isCompatModeActive() {},
+    isConsentRequired() {},
+    isEdge: () => false,
+    isFirefox: () => true,
+    isIE6Or7: () => false,
+    isObject,
+    isRecsDestination: () => false,
+    isSafari: () => false,
+    isTextNode: n => n?.nodeType === 3,
+    isTopWindow: () => window === top,
+    jsonpRequest: () => false,
+    loadScript() {},
+    m_accountId: "0",
+    m_activityEvents: false,
+    m_activityState: {
+      activeTime: startTime,
+      currScrollLeft: 0,
+      currScrollTop: 0,
+      exitLink: "",
+      hadHIDActivity: false,
+      maxViewLeft: 1,
+      maxViewTop: 1,
+      parentMetrics: undefined,
+      prevActivityTime: startTime + 2,
+      prevScreenX: 0,
+      prevScreenY: 0,
+      prevScrollLeft: 0,
+      prevScrollTop: 0,
+      prevTime: startTime + 1,
+      prevWindowHeight: 1,
+      prevWindowWidth: 1,
+      scrollDepthPercentage: 0,
+      scrollDepthPixels: 0,
+    },
+    m_atfr: null,
+    m_c1xTpWait: 0,
+    m_clientStorage: {
+      iframeEl: null,
+      iframeIsLoaded: false,
+      iframeOrigin: "https://clientstorage.cxense.com",
+      iframePath: "/clientstorage_v2.html",
+      messageContexts: {},
+      messageQueue: [],
+    },
+    m_compatMode: {},
+    m_compatModeActive: false,
+    m_compatPvSent: false,
+    m_consentVersion: 1,
+    m_customParameters: [],
+    m_documentSizeRequestedFromChild: false,
+    m_externalUserIds: [],
+    m_globalIdLoading: {
+      globalIdIFrameEl: null,
+      globalIdIFrameElLoaded: false,
+    },
+    m_isSpaRecsDestination: false,
+    m_knownMessageSources: [],
+    m_p1Complete: false,
+    m_prevLocationHash: "",
+    m_previousPageViewReport: null,
+    m_rawCustomParameters: {},
+    m_rnd: getRandomString(),
+    m_scriptStartTime: startTime,
+    m_siteId: "0",
+    m_spaRecsClickUrl: null,
+    m_thirdPartyIds: true,
+    m_usesConsent: false,
+    m_usesIabConsent: false,
+    m_usesSecureCookies: true,
+    m_usesTcf20Consent: false,
+    m_widgetSpecs: {},
+    Object,
+    onClearIds() {},
+    onFFP1() {},
+    onP1() {},
+    p1BaseUrl: "https://scdn.cxense.com/sp1.html",
+    p1JsUrl: "https://p1cluster.cxense.com/p1.js",
+    parseHashArgs: () => Object.create(),
+    parseMargins: () => margins,
+    parseUrlArgs: () => Object.create(),
+    postMessageToParent() {},
+    publicWidgetDataUrl: "https://api.cxense.com/public/widget/data",
+    removeClientStorageVariable() {},
+    removeEventListener() {},
+    renderContainedImage: () => "<div/>",
+    renderTemplate: () => "<div/>",
+    reportActivity() {},
+    requireActivityEvents() {},
+    requireConsent() {},
+    requireOnlyFirstPartyIds() {},
+    requireSecureCookies() {},
+    requireTcf20() {},
+    sendEvent,
+    sendSpaRecsClick: (a, callback) => call(callback),
+    setAccountId() {},
+    setAllConsentsTo() {},
+    setClientStorageVariable() {},
+    setCompatMode() {},
+    setConsent() {},
+    setCookie() {},
+    setCustomParameters() {},
+    setEventAttributes() {},
+    setGeoPosition() {},
+    setNodeValue() {},
+    setRandomId() {},
+    setRestrictionsToConsentClasses() {},
+    setRetargetingParameters() {},
+    setSiteId() {},
+    setUserProfileParameters() {},
+    setupIabCmp() {},
+    setupTcfApi() {},
+    shouldPollActivity() {},
+    startLocalStats() {},
+    startSessionAnnotation() {},
+    stopAllSessionAnnotations() {},
+    stopSessionAnnotation() {},
+    sync() {},
+    trackAmpIFrame() {},
+    trackElement() {},
+    trim: s => s.trim(),
+    tsridUrl: "https://tsrid.cxense.com/lookup?callback={{callback}}",
+    userSegmentUrl:
+      "https://api.cxense.com/profile/user/segment?callback={{callback}}",
+  };
+
+  const libraryCCE = {
+    "__cx-toolkit__": {
+      isShown: true,
+      data: [],
+    },
+    activeSnapPoint: null,
+    activeWidgets: [],
+    ccePushUrl,
+    clickTracker: () => "",
+    displayResult() {},
+    displayWidget,
+    getDivId,
+    getTestGroup: () => testGroup,
+    init,
+    insertMaster() {},
+    instrumentClickLinks() {},
+    invoke: invokeOn(libraryCCE),
+    noCache: false,
+    offerProductId: null,
+    persistedQueryId: null,
+    prefix: null,
+    previewCampaign: null,
+    previewDiv: null,
+    previewId: null,
+    previewTestId: null,
+    processCxResult() {},
+    render,
+    reportTestImpression() {},
+    run,
+    runCtrlVersion,
+    runCxVersion,
+    runMulti,
+    runTest,
+    sendConversionEvent,
+    sendPageViewEvent: (a, b, c, callback) => call(callback),
+    setSnapPoints(x) {
+      snapPoints = x;
+    },
+    setTestGroup(x) {
+      testGroup = x;
+    },
+    setVisibilityField() {},
+    get snapPoints() {
+      return snapPoints;
+    },
+    startTime,
+    get testGroup() {
+      return testGroup;
+    },
+    testVariant: null,
+    trackTime: 0.5,
+    trackVisibility() {},
+    updateRecsClickUrls() {},
+    utmParams: [],
+    version: "2.42",
+    visibilityField: "timeHalf",
+  };
+
+  const CCE = {
+    activeSnapPoint: null,
+    activeWidgets: [],
+    callQueue: callQueueCCE,
+    ccePushUrl,
+    clickTracker: () => "",
+    displayResult() {},
+    displayWidget,
+    getDivId,
+    getTestGroup: () => testGroup,
+    init,
+    insertMaster() {},
+    instrumentClickLinks() {},
+    invoke: invokeOn(libraryCCE),
+    library: libraryCCE,
+    noCache: false,
+    offerProductId: null,
+    persistedQueryId: null,
+    prefix: null,
+    previewCampaign: null,
+    previewDiv: null,
+    previewId: null,
+    previewTestId: null,
+    processCxResult() {},
+    render,
+    reportTestImpression() {},
+    run,
+    runCtrlVersion,
+    runCxVersion,
+    runMulti,
+    runTest,
+    sendConversionEvent,
+    sendPageViewEvent: (a, b, c, callback) => call(callback),
+    setSnapPoints(x) {
+      snapPoints = x;
+    },
+    setTestGroup(x) {
+      testGroup = x;
+    },
+    setVisibilityField() {},
+    get snapPoints() {
+      return snapPoints;
+    },
+    startTime,
+    get testGroup() {
+      return testGroup;
+    },
+    testVariant: null,
+    trackTime: 0.5,
+    trackVisibility() {},
+    updateRecsClickUrls() {},
+    utmParams: [],
+    version: "2.42",
+    visibilityField: "timeHalf",
+  };
+
+  window.cX = {
+    addCustomerScript() {},
+    addEventListener() {},
+    addExternalId() {},
+    afterInitializePage() {},
+    allUserConsents: () => undefined,
+    Array,
+    calculateAdSpaceSize: () => 0,
+    callQueue,
+    CCE,
+    cint: () => undefined,
+    clearCustomParameters() {},
+    clearIds() {},
+    clickTracker: () => "",
+    combineArgs: () => Object.create(),
+    combineKeywordsIntoArray: () => [],
+    createDelegate() {},
+    decodeUrlEncodedNameValuePairs: () => Object.create(),
+    defaultAdRenderer: () => "",
+    deleteCookie() {},
+    getAllText: () => "",
+    getClientStorageVariable() {},
+    getCookie: () => null,
+    getCxenseUserId: () => cxUserId,
+    getDocumentSize,
+    getElementPosition: () => topLeft,
+    getHashFragment: () => location.hash.substr(1),
+    getLocalStats: () => Object.create(),
+    getNodeValue: n => n.nodeValue,
+    getNowSeconds,
+    getPageContext,
+    getRandomString,
+    getScrollPos: () => topLeft,
+    getSessionId: () => "",
+    getSiteId: () => "",
+    getTimezoneOffset: () => new Date().getTimezoneOffset(),
+    getTopLevelDomain: () => location.hostname,
+    getUserId: () => userId,
+    getUserSegmentIds,
+    getWindowSize,
+    hasConsent: () => true,
+    hasHistory: () => true,
+    hasLocalStorage: () => true,
+    hasPassiveEventListeners: () => true,
+    hasPostMessage: () => true,
+    hasSessionStorage() {},
+    initializePage() {},
+    insertAdSpace() {},
+    insertMultipleAdSpaces() {},
+    insertWidget() {},
+    invoke: invokeOn(library),
+    isAmpIFrame() {},
+    isArray() {},
+    isCompatModeActive() {},
+    isConsentRequired() {},
+    isEdge: () => false,
+    isFirefox: () => true,
+    isIE6Or7: () => false,
+    isObject,
+    isRecsDestination: () => false,
+    isSafari: () => false,
+    isTextNode: n => n?.nodeType === 3,
+    isTopWindow: () => window === top,
+    JSON,
+    jsonpRequest: () => false,
+    library,
+    loadScript() {},
+    Object,
+    onClearIds() {},
+    onFFP1() {},
+    onP1() {},
+    parseHashArgs: () => Object.create(),
+    parseMargins: () => margins,
+    parseUrlArgs: () => Object.create(),
+    postMessageToParent() {},
+    removeClientStorageVariable() {},
+    removeEventListener() {},
+    renderContainedImage: () => "<div/>",
+    renderTemplate: () => "<div/>",
+    reportActivity() {},
+    requireActivityEvents() {},
+    requireConsent() {},
+    requireOnlyFirstPartyIds() {},
+    requireSecureCookies() {},
+    requireTcf20() {},
+    sendEvent,
+    sendPageViewEvent: (a, callback) => call(callback, {}),
+    sendSpaRecsClick() {},
+    setAccountId() {},
+    setAllConsentsTo() {},
+    setClientStorageVariable() {},
+    setCompatMode() {},
+    setConsent() {},
+    setCookie() {},
+    setCustomParameters() {},
+    setEventAttributes() {},
+    setGeoPosition() {},
+    setNodeValue() {},
+    setRandomId() {},
+    setRestrictionsToConsentClasses() {},
+    setRetargetingParameters() {},
+    setSiteId() {},
+    setUserProfileParameters() {},
+    setupIabCmp() {},
+    setupTcfApi() {},
+    shouldPollActivity() {},
+    startLocalStats() {},
+    startSessionAnnotation() {},
+    stopAllSessionAnnotations() {},
+    stopSessionAnnotation() {},
+    sync() {},
+    trackAmpIFrame() {},
+    trackElement() {},
+    trim: s => s.trim(),
+  };
+
+  window.cxTest = window.cX;
+
+  window.cx_pollActiveTime = () => undefined;
+  window.cx_pollActivity = () => undefined;
+  window.cx_pollFragmentMessage = () => undefined;
+
+  const execQueue = (lib, queue) => {
+    return () => {
+      const invoke = invokeOn(lib);
+      setTimeout(() => {
+        queue.push = cmd => {
+          setTimeout(() => invoke(...cmd), 1);
+        };
+        for (const cmd of queue) {
+          invoke(...cmd);
+        }
+      }, 25);
+    };
+  };
+
+  window.cx_callQueueExecute = execQueue(library, callQueue);
+  window.cxCCE_callQueueExecute = execQueue(libraryCCE, callQueueCCE);
+
+  window.cx_callQueueExecute();
+  window.cxCCE_callQueueExecute();
+}
diff --git a/browser/extensions/webcompat/shims/doubleverify.js b/browser/extensions/webcompat/shims/doubleverify.js
new file mode 100644
index 0000000000..7eaf945d77
--- /dev/null
+++ b/browser/extensions/webcompat/shims/doubleverify.js
@@ -0,0 +1,36 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1771557 - Shim DoubleVerify analytics
+ *
+ * Some sites such as Sports Illustrated expect DoubleVerify's
+ * analytics script to load, otherwise odd breakage may occur.
+ * This shim helps mitigate such breakage.
+ */
+
+if (!window?.PQ?.loaded) {
+  const cmd = [];
+  cmd.push = function (c) {
+    try {
+      c?.();
+    } catch (_) {}
+  };
+
+  window.apntag = {
+    anq: [],
+  };
+
+  window.PQ = {
+    cmd,
+    loaded: true,
+    getTargeting: (_, cb) => cb?.([]),
+    init: () => {},
+    loadSignals: (_, cb) => cb?.(),
+    loadSignalsForSlots: (_, cb) => cb?.(),
+    PTS: {},
+  };
+}
diff --git a/browser/extensions/webcompat/shims/eluminate.js b/browser/extensions/webcompat/shims/eluminate.js
new file mode 100644
index 0000000000..3fa65c048c
--- /dev/null
+++ b/browser/extensions/webcompat/shims/eluminate.js
@@ -0,0 +1,95 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1606448 - Shim CoreMetrics Eluminate analytics
+ *
+ * Sites may rely on eluminate.js tracking in ways which cause breakage,
+ * which has been seen on shopping sites such as Vans.com, where the
+ * search filtering UX is broken. This shim mitigates such breakage.
+ */
+
+if (!window.CM_DDX) {
+  window.CM_DDX = {
+    domReadyFired: false,
+    headScripts: true,
+    dispatcherLoadRequested: false,
+    firstPassFunctionBinding: false,
+    BAD_PAGE_ID_ELAPSED_TIMEOUT: 5000,
+    version: -1,
+    standalone: false,
+    test: {
+      syndicate: true,
+      testCounter: "",
+      doTest: false,
+      newWin: false,
+      process: () => {},
+    },
+    partner: {},
+    invokeFunctionWhenAvailable: a => {
+      a();
+    },
+    gup: d => "",
+    privacy: {
+      isDoNotTrackEnabled: () => false,
+      setDoNotTrack: () => {},
+      getDoNotTrack: () => false,
+    },
+    setSubCookie: () => {},
+  };
+  const noopfn = () => {};
+  const w = window;
+  w.cmAddShared = noopfn;
+  w.cmCalcSKUString = noopfn;
+  w.cmCreateManualImpressionTag = noopfn;
+  w.cmCreateManualLinkClickTag = noopfn;
+  w.cmCreateManualPageviewTag = noopfn;
+  w.cmCreateOrderTag = noopfn;
+  w.cmCreatePageviewTag = noopfn;
+  w.cmExecuteTagQueue = noopfn;
+  w.cmRetrieveUserID = noopfn;
+  w.cmSetClientID = noopfn;
+  w.cmSetCurrencyCode = noopfn;
+  w.cmSetFirstPartyIDs = noopfn;
+  w.cmSetSubCookie = noopfn;
+  w.cmSetupCookieMigration = noopfn;
+  w.cmSetupNormalization = noopfn;
+  w.cmSetupOther = noopfn;
+  w.cmStartTagSet = noopfn;
+  w.cmCreateConversionEventTag = noopfn;
+  w.cmCreateDefaultPageviewTag = noopfn;
+  w.cmCreateElementTag = noopfn;
+  w.cmCreateManualImpressionTag = noopfn;
+  w.cmCreateManualLinkClickTag = noopfn;
+  w.cmCreateManualPageviewTag = noopfn;
+  w.cmCreatePageElementTag = noopfn;
+  w.cmCreatePageviewTag = noopfn;
+  w.cmCreateProductElementTag = noopfn;
+  w.cmCreateProductviewTag = noopfn;
+  w.cmCreateTechPropsTag = noopfn;
+  w.cmLoadIOConfig = noopfn;
+  w.cmSetClientID = noopfn;
+  w.cmSetCurrencyCode = noopfn;
+  w.cmSetFirstPartyIDs = noopfn;
+  w.cmSetupCookieMigration = noopfn;
+  w.cmSetupNormalization = noopfn;
+
+  w.cmSetupOther = b => {
+    for (const a in b) {
+      window[a] = b[a];
+    }
+  };
+
+  const techProps = {};
+
+  w.coremetrics = {
+    cmLastReferencedPageID: "",
+    cmLoad: noopfn,
+    cmUpdateConfig: noopfn,
+    getTechProps: () => techProps,
+    isDef: c => typeof c !== "undefined" && c,
+  };
+}
diff --git a/browser/extensions/webcompat/shims/empty-script.js b/browser/extensions/webcompat/shims/empty-script.js
new file mode 100644
index 0000000000..d01f2ab537
--- /dev/null
+++ b/browser/extensions/webcompat/shims/empty-script.js
@@ -0,0 +1,5 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* This script is intentionally empty */
diff --git a/browser/extensions/webcompat/shims/empty-shim.txt b/browser/extensions/webcompat/shims/empty-shim.txt
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/browser/extensions/webcompat/shims/empty-shim.txt
diff --git a/browser/extensions/webcompat/shims/everest.js b/browser/extensions/webcompat/shims/everest.js
new file mode 100644
index 0000000000..259ab9033e
--- /dev/null
+++ b/browser/extensions/webcompat/shims/everest.js
@@ -0,0 +1,171 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1728114 - Shim Adobe EverestJS
+ *
+ * Sites assuming EverestJS will load can break if it is blocked.
+ * This shim mitigates that breakage.
+ */
+
+if (!window.__ql) {
+  window.__ql = {};
+}
+
+if (!window.EF) {
+  const AdCloudLocalStorage = {
+    get: (_, cb) => cb(),
+    isInitDone: true,
+    isInitSuccess: true,
+  };
+
+  const emptyObj = {};
+
+  const nullSrc = {
+    getHosts: () => [undefined],
+    getProtocols: () => [undefined],
+    hash: {},
+    hashParamsOrder: [],
+    host: undefined,
+    path: [],
+    port: undefined,
+    query: {},
+    queryDelimiter: "&",
+    queryParamsOrder: [],
+    queryPrefix: "?",
+    queryWithoutEncode: {},
+    respectEmptyQueryParamValue: undefined,
+    scheme: undefined,
+    text: "//",
+    userInfo: undefined,
+  };
+
+  const pixelDetailsEvent = {
+    addToDom() {},
+    canAddToDom: () => false,
+    fire() {},
+    getDomElement() {},
+    initializeUri() {},
+    pixelDetailsReceiver() {},
+    scheme: "https:",
+    uri: nullSrc,
+    userid: 0,
+  };
+
+  window.EF = {
+    AdCloudLocalStorage,
+    accessTopUrl: 0,
+    acquireCookieMatchingSlot() {},
+    addListener() {},
+    addPixelDetailsReadyListener() {},
+    addToDom() {},
+    allow3rdPartyPixels: 1,
+    appData: "",
+    appendDictionary() {},
+    checkGlobalSid() {},
+    checkUrlParams() {},
+    cmHost: "cm.everesttech.net",
+    context: {
+      isFbApp: () => 0,
+      isPageview: () => false,
+      isSegmentation: () => false,
+      isTransaction: () => false,
+    },
+    conversionData: "",
+    cookieMatchingSlots: 1,
+    debug: 0,
+    deserializeUrlParams: () => emptyObj,
+    doCookieMatching() {},
+    ef_itp_ls: false,
+    eventType: "",
+    executeAfterLoad() {},
+    executeOnloadCallbacks() {},
+    expectedTrackingParams: ["ev_cl", "ev_sid"],
+    fbIsApp: 0,
+    fbsCM: 0,
+    fbsPixelId: 0,
+    filterList: () => [],
+    getArrayIndex: -1,
+    getConversionData: () => "",
+    getConversionDataFromLocalStorage: cb => cb(),
+    getDisplayClickUri: () => "",
+    getEpochFromEfUniq: () => 0,
+    getFirstLevelObjectCopy: () => emptyObj,
+    getInvisibleIframeElement() {},
+    getInvisibleImageElement() {},
+    getMacroSubstitutedText: () => "",
+    getPixelDetails: cb => cb({}),
+    getScriptElement() {},
+    getScriptSrc: () => "",
+    getServerParams: () => emptyObj,
+    getSortedAttributes: () => [],
+    getTrackingParams: () => emptyObj,
+    getTransactionParams: () => emptyObj,
+    handleConversionData() {},
+    impressionProperties: "",
+    impressionTypes: ["impression", "impression_served"],
+    inFloodlight: 0,
+    init(config) {
+      try {
+        const { userId } = config;
+        window.EF.userId = userId;
+        pixelDetailsEvent.userId = userId;
+      } catch (_) {}
+    },
+    initializeEFVariables() {},
+    isArray: a => Array.isArray(a),
+    isEmptyDictionary: () => true,
+    isITPEnabled: () => false,
+    isPermanentCookieSet: () => false,
+    isSearchClick: () => 0,
+    isXSSReady() {},
+    jsHost: "www.everestjs.net",
+    jsTagAdded: 0,
+    location: nullSrc,
+    locationHref: nullSrc,
+    locationSkipBang: nullSrc,
+    log() {},
+    main() {},
+    main2() {},
+    newCookieMatchingEvent: () => emptyObj,
+    newFbsCookieMatching: () => emptyObj,
+    newImpression: () => emptyObj,
+    newPageview: () => emptyObj,
+    newPixelDetails: () => emptyObj,
+    newPixelEvent: () => emptyObj,
+    newPixelServerDisplayClickRedirectUri: () => emptyObj,
+    newPixelServerGenericRedirectUri: () => emptyObj,
+    newPixelServerUri: () => emptyObj,
+    newProductSegment: () => emptyObj,
+    newSegmentJavascript: () => emptyObj,
+    newTransaction: () => emptyObj,
+    newUri: () => emptyObj,
+    onloadCallbacks: [],
+    pageViewProperties: "",
+    pageviewProperties: "",
+    pixelDetails: {},
+    pixelDetailsAdded: 1,
+    pixelDetailsEvent,
+    pixelDetailsParams: [],
+    pixelDetailsReadyCallbackFns: [],
+    pixelDetailsRecieverCalled: 1,
+    pixelHost: "pixel.everesttech.net",
+    protocol: document?.location?.protocol || "",
+    referrer: nullSrc,
+    removeListener() {},
+    searchSegment: "",
+    segment: "",
+    serverParamsListener() {},
+    sid: 0,
+    sku: "",
+    throttleCookie: "",
+    trackingJavascriptSrc: nullSrc,
+    transactionObjectList: [],
+    transactionProperties: "",
+    userServerParams: {},
+    userid: 0,
+  };
+}
diff --git a/browser/extensions/webcompat/shims/facebook-sdk.js b/browser/extensions/webcompat/shims/facebook-sdk.js
new file mode 100644
index 0000000000..1e995ff047
--- /dev/null
+++ b/browser/extensions/webcompat/shims/facebook-sdk.js
@@ -0,0 +1,554 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1226498 - Shim Facebook SDK
+ *
+ * This shim provides functionality to enable Facebook's authenticator on third
+ * party sites ("continue/log in with Facebook" buttons). This includes rendering
+ * the button as the SDK would, if sites require it. This way, if users wish to
+ * opt into the Facebook login process regardless of the tracking consequences,
+ * they only need to click the button as usual.
+ *
+ * In addition, the shim also attempts to provide placeholders for Facebook
+ * videos, which users may click to opt into seeing the video (also despite
+ * the increased tracking risks). This is an experimental feature enabled
+ * that is only currently enabled on nightly builds.
+ *
+ * Finally, this shim also stubs out as much of the SDK as possible to prevent
+ * breaking on sites which expect that it will always successfully load.
+ */
+
+if (!window.FB) {
+  const FacebookLogoURL = "https://smartblock.firefox.etp/facebook.svg";
+  const PlayIconURL = "https://smartblock.firefox.etp/play.svg";
+
+  const originalUrl = document.currentScript.src;
+
+  let haveUnshimmed;
+  let initInfo;
+  let activeOnloginAttribute;
+  const placeholdersToRemoveOnUnshim = new Set();
+  const loggedGraphApiCalls = [];
+  const eventHandlers = new Map();
+
+  function getGUID() {
+    const v = crypto.getRandomValues(new Uint8Array(20));
+    return Array.from(v, c => c.toString(16)).join("");
+  }
+
+  const sendMessageToAddon = (function () {
+    const shimId = "FacebookSDK";
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function (message) {
+      const messageId = getGUID();
+      return new Promise(resolve => {
+        const payload = { message, messageId, shimId };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  const isNightly = sendMessageToAddon("getOptions").then(opts => {
+    return opts.releaseBranch === "nightly";
+  });
+
+  function makeLoginPlaceholder(target) {
+    // Sites may provide their own login buttons, or rely on the Facebook SDK
+    // to render one for them. For the latter case, we provide placeholders
+    // which try to match the examples and documentation here:
+    // https://developers.facebook.com/docs/facebook-login/web/login-button/
+
+    if (target.textContent || target.hasAttribute("fb-xfbml-state")) {
+      return;
+    }
+    target.setAttribute("fb-xfbml-state", "");
+
+    const size = target.getAttribute("data-size") || "large";
+
+    let font, margin, minWidth, maxWidth, height, iconHeight;
+    if (size === "small") {
+      font = 11;
+      margin = 8;
+      minWidth = maxWidth = 200;
+      height = 20;
+      iconHeight = 12;
+    } else if (size === "medium") {
+      font = 13;
+      margin = 8;
+      minWidth = 200;
+      maxWidth = 320;
+      height = 28;
+      iconHeight = 16;
+    } else {
+      font = 16;
+      minWidth = 240;
+      maxWidth = 400;
+      margin = 12;
+      height = 40;
+      iconHeight = 24;
+    }
+
+    const wattr = target.getAttribute("data-width") || "";
+    const width =
+      wattr === "100%" ? wattr : `${parseFloat(wattr) || minWidth}px`;
+
+    const round = target.getAttribute("data-layout") === "rounded" ? 20 : 4;
+
+    const text =
+      target.getAttribute("data-button-type") === "continue_with"
+        ? "Continue with Facebook"
+        : "Log in with Facebook";
+
+    const button = document.createElement("div");
+    button.style = `
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      padding-left: ${margin + iconHeight}px;
+      ${width};
+      min-width: ${minWidth}px;
+      max-width: ${maxWidth}px;
+      height: ${height}px;
+      border-radius: ${round}px;
+      -moz-text-size-adjust: none;
+      -moz-user-select: none;
+      color: #fff;
+      font-size: ${font}px;
+      font-weight: bold;
+      font-family: Helvetica, Arial, sans-serif;
+      letter-spacing: .25px;
+      background-color: #1877f2;
+      background-repeat: no-repeat;
+      background-position: ${margin}px 50%;
+      background-size: ${iconHeight}px ${iconHeight}px;
+      background-image: url(${FacebookLogoURL});
+    `;
+    button.textContent = text;
+    target.appendChild(button);
+    target.addEventListener("click", () => {
+      activeOnloginAttribute = target.getAttribute("onlogin");
+    });
+  }
+
+  async function makeVideoPlaceholder(target) {
+    // For videos, we provide a more generic placeholder of roughly the
+    // expected size with a play button, as well as a Facebook logo.
+    if (!(await isNightly) || target.hasAttribute("fb-xfbml-state")) {
+      return;
+    }
+    target.setAttribute("fb-xfbml-state", "");
+
+    let width = parseInt(target.getAttribute("data-width"));
+    let height = parseInt(target.getAttribute("data-height"));
+    if (height) {
+      height = `${width * 0.6}px`;
+    } else {
+      height = `100%; min-height:${width * 0.75}px`;
+    }
+    if (width) {
+      width = `${width}px`;
+    } else {
+      width = `100%; min-width:200px`;
+    }
+
+    const placeholder = document.createElement("div");
+    placeholdersToRemoveOnUnshim.add(placeholder);
+    placeholder.style = `
+      width: ${width};
+      height: ${height};
+      top: 0px;
+      left: 0px;
+      background: #000;
+      color: #fff;
+      text-align: center;
+      cursor: pointer;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      background-image: url(${FacebookLogoURL}), url(${PlayIconURL});
+      background-position: calc(100% - 24px) 24px, 50% 47.5%;
+      background-repeat: no-repeat, no-repeat;
+      background-size: 43px 42px, 25% 25%;
+      -moz-text-size-adjust: none;
+      -moz-user-select: none;
+      color: #fff;
+      align-items: center;
+      padding-top: 200px;
+      font-size: 14pt;
+    `;
+    placeholder.textContent = "Click to allow blocked Facebook content";
+    placeholder.addEventListener("click", evt => {
+      if (!evt.isTrusted) {
+        return;
+      }
+      allowFacebookSDK(() => {
+        placeholdersToRemoveOnUnshim.forEach(p => p.remove());
+      });
+    });
+
+    target.innerHTML = "";
+    target.appendChild(placeholder);
+  }
+
+  // We monitor for XFBML objects as Facebook SDK does, so we
+  // can provide placeholders for dynamically-added ones.
+  const xfbmlObserver = new MutationObserver(mutations => {
+    for (let { addedNodes, target, type } of mutations) {
+      const nodes = type === "attributes" ? [target] : addedNodes;
+      for (const node of nodes) {
+        if (node?.classList?.contains("fb-login-button")) {
+          makeLoginPlaceholder(node);
+        }
+        if (node?.classList?.contains("fb-video")) {
+          makeVideoPlaceholder(node);
+        }
+      }
+    }
+  });
+
+  xfbmlObserver.observe(document.documentElement, {
+    childList: true,
+    subtree: true,
+    attributes: true,
+    attributeFilter: ["class"],
+  });
+
+  const needPopup =
+    !/app_runner/.test(window.name) && !/iframe_canvas/.test(window.name);
+  const popupName = getGUID();
+  let activePopup;
+
+  if (needPopup) {
+    const oldWindowOpen = window.open;
+    window.open = function (href, name, params) {
+      try {
+        const url = new URL(href, window.location.href);
+        if (
+          url.protocol === "https:" &&
+          (url.hostname === "m.facebook.com" ||
+            url.hostname === "www.facebook.com") &&
+          url.pathname.endsWith("/oauth")
+        ) {
+          name = popupName;
+        }
+      } catch (e) {
+        console.error(e);
+      }
+      return oldWindowOpen.call(window, href, name, params);
+    };
+  }
+
+  let allowingFacebookPromise;
+
+  async function allowFacebookSDK(postInitCallback) {
+    if (allowingFacebookPromise) {
+      return allowingFacebookPromise;
+    }
+
+    let resolve, reject;
+    allowingFacebookPromise = new Promise((_resolve, _reject) => {
+      resolve = _resolve;
+      reject = _reject;
+    });
+
+    await sendMessageToAddon("optIn");
+
+    xfbmlObserver.disconnect();
+
+    const shim = window.FB;
+    window.FB = undefined;
+
+    // We need to pass the site's initialization info to the real
+    // SDK as it loads, so we use the fbAsyncInit mechanism to
+    // do so, also ensuring our own post-init callbacks are called.
+    const oldInit = window.fbAsyncInit;
+    window.fbAsyncInit = () => {
+      try {
+        if (typeof initInfo !== "undefined") {
+          window.FB.init(initInfo);
+        } else if (oldInit) {
+          oldInit();
+        }
+      } catch (e) {
+        console.error(e);
+      }
+
+      // Also re-subscribe any SDK event listeners as early as possible.
+      for (const [name, fns] of eventHandlers.entries()) {
+        for (const fn of fns) {
+          window.FB.Event.subscribe(name, fn);
+        }
+      }
+
+      // Allow the shim to do any post-init work early as well, while the
+      // SDK script finishes loading and we ask it to re-parse XFBML etc.
+      postInitCallback?.();
+    };
+
+    const script = document.createElement("script");
+    script.src = originalUrl;
+
+    script.addEventListener("error", () => {
+      allowingFacebookPromise = null;
+      script.remove();
+      activePopup?.close();
+      window.FB = shim;
+      reject();
+      alert("Failed to load Facebook SDK; please try again");
+    });
+
+    script.addEventListener("load", () => {
+      haveUnshimmed = true;
+
+      // After the real SDK has fully loaded we re-issue any Graph API
+      // calls the page is waiting on, as well as requesting for it to
+      // re-parse any XBFML elements (including ones with placeholders).
+
+      for (const args of loggedGraphApiCalls) {
+        try {
+          window.FB.api.apply(window.FB, args);
+        } catch (e) {
+          console.error(e);
+        }
+      }
+
+      window.FB.XFBML.parse(document.body, resolve);
+    });
+
+    document.head.appendChild(script);
+
+    return allowingFacebookPromise;
+  }
+
+  function buildPopupParams() {
+    // We try to match Facebook's popup size reasonably closely.
+    const { outerWidth, outerHeight, screenX, screenY } = window;
+    const { width, height } = window.screen;
+    const w = Math.min(width, 400);
+    const h = Math.min(height, 400);
+    const ua = navigator.userAgent;
+    const isMobile = ua.includes("Mobile") || ua.includes("Tablet");
+    const left = screenX + (screenX < 0 ? width : 0) + (outerWidth - w) / 2;
+    const top = screenY + (screenY < 0 ? height : 0) + (outerHeight - h) / 2.5;
+    let params = `left=${left},top=${top},width=${w},height=${h},scrollbars=1,toolbar=0,location=1`;
+    if (!isMobile) {
+      params = `${params},width=${w},height=${h}`;
+    }
+    return params;
+  }
+
+  // If a page stores the window.FB reference of the shim, then we
+  // want to have it proxy calls to the real SDK once we've unshimmed.
+  function ensureProxiedToUnshimmed(obj) {
+    const shim = {};
+    for (const key in obj) {
+      const value = obj[key];
+      if (typeof value === "function") {
+        shim[key] = function () {
+          if (haveUnshimmed) {
+            return window.FB[key].apply(window.FB, arguments);
+          }
+          return value.apply(this, arguments);
+        };
+      } else if (typeof value !== "object" || value === null) {
+        shim[key] = value;
+      } else {
+        shim[key] = ensureProxiedToUnshimmed(value);
+      }
+    }
+    return new Proxy(shim, {
+      get: (shimmed, key) => (haveUnshimmed ? window.FB : shimmed)[key],
+    });
+  }
+
+  window.FB = ensureProxiedToUnshimmed({
+    api() {
+      loggedGraphApiCalls.push(arguments);
+    },
+    AppEvents: {
+      activateApp() {},
+      clearAppVersion() {},
+      clearUserID() {},
+      EventNames: {
+        ACHIEVED_LEVEL: "fb_mobile_level_achieved",
+        ADDED_PAYMENT_INFO: "fb_mobile_add_payment_info",
+        ADDED_TO_CART: "fb_mobile_add_to_cart",
+        ADDED_TO_WISHLIST: "fb_mobile_add_to_wishlist",
+        COMPLETED_REGISTRATION: "fb_mobile_complete_registration",
+        COMPLETED_TUTORIAL: "fb_mobile_tutorial_completion",
+        INITIATED_CHECKOUT: "fb_mobile_initiated_checkout",
+        PAGE_VIEW: "fb_page_view",
+        RATED: "fb_mobile_rate",
+        SEARCHED: "fb_mobile_search",
+        SPENT_CREDITS: "fb_mobile_spent_credits",
+        UNLOCKED_ACHIEVEMENT: "fb_mobile_achievement_unlocked",
+        VIEWED_CONTENT: "fb_mobile_content_view",
+      },
+      getAppVersion: () => "",
+      getUserID: () => "",
+      logEvent() {},
+      logPageView() {},
+      logPurchase() {},
+      ParameterNames: {
+        APP_USER_ID: "_app_user_id",
+        APP_VERSION: "_appVersion",
+        CONTENT_ID: "fb_content_id",
+        CONTENT_TYPE: "fb_content_type",
+        CURRENCY: "fb_currency",
+        DESCRIPTION: "fb_description",
+        LEVEL: "fb_level",
+        MAX_RATING_VALUE: "fb_max_rating_value",
+        NUM_ITEMS: "fb_num_items",
+        PAYMENT_INFO_AVAILABLE: "fb_payment_info_available",
+        REGISTRATION_METHOD: "fb_registration_method",
+        SEARCH_STRING: "fb_search_string",
+        SUCCESS: "fb_success",
+      },
+      setAppVersion() {},
+      setUserID() {},
+      updateUserProperties() {},
+    },
+    Canvas: {
+      getHash: () => "",
+      getPageInfo(cb) {
+        cb?.call(this, {
+          clientHeight: 1,
+          clientWidth: 1,
+          offsetLeft: 0,
+          offsetTop: 0,
+          scrollLeft: 0,
+          scrollTop: 0,
+        });
+      },
+      Plugin: {
+        hidePluginElement() {},
+        showPluginElement() {},
+      },
+      Prefetcher: {
+        COLLECT_AUTOMATIC: 0,
+        COLLECT_MANUAL: 1,
+        addStaticResource() {},
+        setCollectionMode() {},
+      },
+      scrollTo() {},
+      setAutoGrow() {},
+      setDoneLoading() {},
+      setHash() {},
+      setSize() {},
+      setUrlHandler() {},
+      startTimer() {},
+      stopTimer() {},
+    },
+    Event: {
+      subscribe(e, f) {
+        if (!eventHandlers.has(e)) {
+          eventHandlers.set(e, new Set());
+        }
+        eventHandlers.get(e).add(f);
+      },
+      unsubscribe(e, f) {
+        eventHandlers.get(e)?.delete(f);
+      },
+    },
+    frictionless: {
+      init() {},
+      isAllowed: () => false,
+    },
+    gamingservices: {
+      friendFinder() {},
+      uploadImageToMediaLibrary() {},
+    },
+    getAccessToken: () => null,
+    getAuthResponse() {
+      return { status: "" };
+    },
+    getLoginStatus(cb) {
+      cb?.call(this, { status: "unknown" });
+    },
+    getUserID() {},
+    init(_initInfo) {
+      initInfo = _initInfo; // in case the site is not using fbAsyncInit
+    },
+    login(cb, opts) {
+      // We have to load Facebook's script, and then wait for it to call
+      // window.open. By that time, the popup blocker will likely trigger.
+      // So we open a popup now with about:blank, and then make sure FB
+      // will re-use that same popup later.
+      if (needPopup) {
+        activePopup = window.open("about:blank", popupName, buildPopupParams());
+      }
+      allowFacebookSDK(() => {
+        activePopup = undefined;
+        function runPostLoginCallbacks() {
+          try {
+            cb?.apply(this, arguments);
+          } catch (e) {
+            console.error(e);
+          }
+          if (activeOnloginAttribute) {
+            setTimeout(activeOnloginAttribute, 1);
+            activeOnloginAttribute = undefined;
+          }
+        }
+        window.FB.login(runPostLoginCallbacks, opts);
+      }).catch(() => {
+        activePopup = undefined;
+        activeOnloginAttribute = undefined;
+        try {
+          cb?.({});
+        } catch (e) {
+          console.error(e);
+        }
+      });
+    },
+    logout(cb) {
+      cb?.call(this);
+    },
+    ui(params, fn) {
+      if (params.method === "permissions.oauth") {
+        window.FB.login(fn, params);
+      }
+    },
+    XFBML: {
+      parse(node, cb) {
+        node = node || document;
+        node.querySelectorAll(".fb-login-button").forEach(makeLoginPlaceholder);
+        node.querySelectorAll(".fb-video").forEach(makeVideoPlaceholder);
+        try {
+          cb?.call(this);
+        } catch (e) {
+          console.error(e);
+        }
+      },
+    },
+  });
+
+  window.FB.XFBML.parse();
+
+  window?.fbAsyncInit?.();
+}
diff --git a/browser/extensions/webcompat/shims/facebook.svg b/browser/extensions/webcompat/shims/facebook.svg
new file mode 100644
index 0000000000..df63700a9e
--- /dev/null
+++ b/browser/extensions/webcompat/shims/facebook.svg
@@ -0,0 +1,3 @@
+<!-- copyright is dedicated to the Public Domain.
+     https://en.wikipedia.org/wiki/File:Facebook_f_logo_(2019).svg -->
+<svg xmlns="http://www.w3.org/2000/svg" width="1365.12" height="1365.12" viewBox="0 0 14222 14222"><circle cx="7111" cy="7112" r="7111" fill="#fff"/><path d="M9879 9168l315-2056H8222V5778c0-562 275-1111 1159-1111h897V2917s-814-139-1592-139c-1624 0-2686 984-2686 2767v1567H4194v2056h1806v4969c362 57 733 86 1111 86s749-30 1111-86V9168z" fill="#1977f3"/></svg>
diff --git a/browser/extensions/webcompat/shims/fastclick.js b/browser/extensions/webcompat/shims/fastclick.js
new file mode 100644
index 0000000000..ad6814c995
--- /dev/null
+++ b/browser/extensions/webcompat/shims/fastclick.js
@@ -0,0 +1,75 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1738220 - Shim Conversant FastClick
+ *
+ * Sites assuming FastClick will load can break if it is blocked.
+ * This shim mitigates that breakage.
+ */
+
+// FastClick bundles nodeJS packages/core-js/internals/dom-iterables.js
+// which is known to be needed by at least one site.
+if (!HTMLCollection.prototype.forEach) {
+  const DOMIterables = [
+    "CSSRuleList",
+    "CSSStyleDeclaration",
+    "CSSValueList",
+    "ClientRectList",
+    "DOMRectList",
+    "DOMStringList",
+    "DOMTokenList",
+    "DataTransferItemList",
+    "FileList",
+    "HTMLAllCollection",
+    "HTMLCollection",
+    "HTMLFormElement",
+    "HTMLSelectElement",
+    "MediaList",
+    "MimeTypeArray",
+    "NamedNodeMap",
+    "NodeList",
+    "PaintRequestList",
+    "Plugin",
+    "PluginArray",
+    "SVGLengthList",
+    "SVGNumberList",
+    "SVGPathSegList",
+    "SVGPointList",
+    "SVGStringList",
+    "SVGTransformList",
+    "SourceBufferList",
+    "StyleSheetList",
+    "TextTrackCueList",
+    "TextTrackList",
+    "TouchList",
+  ];
+
+  const forEach = Array.prototype.forEach;
+
+  const handlePrototype = proto => {
+    if (!proto || proto.forEach === forEach) {
+      return;
+    }
+    try {
+      Object.defineProperty(proto, "forEach", {
+        enumerable: false,
+        get: () => forEach,
+      });
+    } catch (_) {
+      proto.forEach = forEach;
+    }
+  };
+
+  for (const name of DOMIterables) {
+    handlePrototype(window[name]?.prototype);
+  }
+}
+
+if (!window.conversant?.launch) {
+  const c = (window.conversant = window.conversant || {});
+  c.launch = () => {};
+}
diff --git a/browser/extensions/webcompat/shims/firebase.js b/browser/extensions/webcompat/shims/firebase.js
new file mode 100644
index 0000000000..8ac049c5e4
--- /dev/null
+++ b/browser/extensions/webcompat/shims/firebase.js
@@ -0,0 +1,95 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1767407 - Shim Firebase
+ *
+ * Sites relying on firebase-messaging.js will break in Private
+ * browsing mode because it assumes that they require service
+ * workers and indexedDB, when they generally do not.
+ */
+
+/* globals cloneInto */
+
+(function () {
+  const win = window.wrappedJSObject;
+  const emptyObj = new win.Object();
+  const emptyArr = new win.Array();
+  const emptyMsg = cloneInto({ message: "" }, window);
+  const noOpFn = cloneInto(function () {}, window, { cloneFunctions: true });
+
+  if (!win.indexedDB) {
+    const idb = {
+      open: () => win.Promise.reject(emptyMsg),
+    };
+
+    Object.defineProperty(win, "indexedDB", {
+      value: cloneInto(idb, window, { cloneFunctions: true }),
+    });
+  }
+
+  // bug 1778993
+  for (const name of [
+    "IDBCursor",
+    "IDBDatabase",
+    "IDBIndex",
+    "IDBOpenDBRequest",
+    "IDBRequest",
+    "IDBTransaction",
+  ]) {
+    if (!win[name]) {
+      Object.defineProperty(win, name, { value: emptyObj });
+    }
+  }
+
+  if (!win.serviceWorker) {
+    const sw = {
+      addEventListener() {},
+      getRegistrations: () => win.Promise.resolve(emptyArr),
+      register: () => win.Promise.reject(emptyMsg),
+    };
+
+    Object.defineProperty(navigator.wrappedJSObject, "serviceWorker", {
+      value: cloneInto(sw, window, { cloneFunctions: true }),
+    });
+
+    // bug 1779536
+    Object.defineProperty(navigator.wrappedJSObject.serviceWorker, "ready", {
+      value: new win.Promise(noOpFn),
+    });
+  }
+
+  // bug 1750699
+  if (!win.PushManager) {
+    Object.defineProperty(win, "PushManager", { value: emptyObj });
+  }
+
+  // bug 1750699
+  if (!win.PushSubscription) {
+    const ps = {
+      prototype: {
+        getKey() {},
+      },
+    };
+
+    Object.defineProperty(win, "PushSubscription", {
+      value: cloneInto(ps, window, { cloneFunctions: true }),
+    });
+  }
+
+  // bug 1750699
+  if (!win.ServiceWorkerRegistration) {
+    const swr = {
+      prototype: {
+        showNotification() {},
+      },
+    };
+
+    Object.defineProperty(win, "ServiceWorkerRegistration", {
+      value: cloneInto(swr, window, { cloneFunctions: true }),
+    });
+  }
+})();
diff --git a/browser/extensions/webcompat/shims/google-ads.js b/browser/extensions/webcompat/shims/google-ads.js
new file mode 100644
index 0000000000..a432186f43
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-ads.js
@@ -0,0 +1,77 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713726 - Shim Ads by Google
+ *
+ * Sites relying on window.adsbygoogle may encounter breakage if it is blocked.
+ * This shim provides a stub for that API to mitigate that breakage.
+ */
+
+if (window.adsbygoogle?.loaded === undefined) {
+  window.adsbygoogle = {
+    loaded: true,
+    push() {},
+  };
+}
+
+if (window.gapi?._pl === undefined) {
+  const stub = {
+    go() {},
+    render: () => "",
+  };
+  window.gapi = {
+    _pl: true,
+    additnow: stub,
+    autocomplete: stub,
+    backdrop: stub,
+    blogger: stub,
+    commentcount: stub,
+    comments: stub,
+    community: stub,
+    donation: stub,
+    family_creation: stub,
+    follow: stub,
+    hangout: stub,
+    health: stub,
+    interactivepost: stub,
+    load() {},
+    logutil: {
+      enableDebugLogging() {},
+    },
+    page: stub,
+    partnersbadge: stub,
+    person: stub,
+    platform: {
+      go() {},
+    },
+    playemm: stub,
+    playreview: stub,
+    plus: stub,
+    plusone: stub,
+    post: stub,
+    profile: stub,
+    ratingbadge: stub,
+    recobar: stub,
+    savetoandroidpay: stub,
+    savetodrive: stub,
+    savetowallet: stub,
+    share: stub,
+    sharetoclassroom: stub,
+    shortlists: stub,
+    signin: stub,
+    signin2: stub,
+    surveyoptin: stub,
+    visibility: stub,
+    youtube: stub,
+    ytsubscribe: stub,
+    zoomableimage: stub,
+  };
+}
+
+for (const e of document.querySelectorAll("ins.adsbygoogle")) {
+  e.style.maxWidth = "0px";
+}
diff --git a/browser/extensions/webcompat/shims/google-analytics-and-tag-manager.js b/browser/extensions/webcompat/shims/google-analytics-and-tag-manager.js
new file mode 100644
index 0000000000..8809fca8ec
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-analytics-and-tag-manager.js
@@ -0,0 +1,187 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713687 - Shim Google Analytics and Tag Manager
+ *
+ * Sites often rely on the Google Analytics window object and will
+ * break if it fails to load or is blocked. This shim works around
+ * such breakage.
+ *
+ * Sites also often use the Google Optimizer (asynchide) code snippet,
+ * only for it to cause multi-second delays if Google Analytics does
+ * not load. This shim also avoids such delays.
+ *
+ * They also rely on Google Tag Manager, which often goes hand-in-
+ * hand with Analytics, but is not always blocked by anti-tracking
+ * lists. Handling both in the same shim handles both cases.
+ */
+
+if (window[window.GoogleAnalyticsObject || "ga"]?.loaded === undefined) {
+  const DEFAULT_TRACKER_NAME = "t0";
+
+  const trackers = new Map();
+
+  const run = function (fn, ...args) {
+    if (typeof fn === "function") {
+      try {
+        fn(...args);
+      } catch (e) {
+        console.error(e);
+      }
+    }
+  };
+
+  const create = (id, cookie, name, opts) => {
+    id = id || opts?.trackerId;
+    if (!id) {
+      return undefined;
+    }
+    cookie = cookie || opts?.cookieDomain || "_ga";
+    name = name || opts?.name || DEFAULT_TRACKER_NAME;
+    if (!trackers.has(name)) {
+      let props;
+      try {
+        props = new Map(Object.entries(opts));
+      } catch (_) {
+        props = new Map();
+      }
+      trackers.set(name, {
+        get(p) {
+          if (p === "name") {
+            return name;
+          } else if (p === "trackingId") {
+            return id;
+          } else if (p === "cookieDomain") {
+            return cookie;
+          }
+          return props.get(p);
+        },
+        ma() {},
+        requireSync() {},
+        send() {},
+        set(p, v) {
+          if (typeof p !== "object") {
+            p = Object.fromEntries([[p, v]]);
+          }
+          for (const k in p) {
+            props.set(k, p[k]);
+            if (k === "hitCallback") {
+              run(p[k]);
+            }
+          }
+        },
+      });
+    }
+    return trackers.get(name);
+  };
+
+  const cmdRE = /((?<name>.*?)\.)?((?<plugin>.*?):)?(?<method>.*)/;
+
+  function ga(cmd, ...args) {
+    if (arguments.length === 1 && typeof cmd === "function") {
+      run(cmd, trackers.get(DEFAULT_TRACKER_NAME));
+      return undefined;
+    }
+
+    if (typeof cmd !== "string") {
+      return undefined;
+    }
+
+    const groups = cmdRE.exec(cmd)?.groups;
+    if (!groups) {
+      console.error("Could not parse GA command", cmd);
+      return undefined;
+    }
+
+    let { name, plugin, method } = groups;
+
+    if (plugin) {
+      return undefined;
+    }
+
+    if (cmd === "set") {
+      trackers.get(name)?.set(args[0], args[1]);
+    }
+
+    if (method === "remove") {
+      trackers.delete(name);
+      return undefined;
+    }
+
+    if (cmd === "send") {
+      run(args.at(-1)?.hitCallback);
+      return undefined;
+    }
+
+    if (method === "create") {
+      let id, cookie, fields;
+      for (const param of args.slice(0, 4)) {
+        if (typeof param === "object") {
+          fields = param;
+          break;
+        }
+        if (id === undefined) {
+          id = param;
+        } else if (cookie === undefined) {
+          cookie = param;
+        } else {
+          name = param;
+        }
+      }
+      return create(id, cookie, name, fields);
+    }
+
+    return undefined;
+  }
+
+  Object.assign(ga, {
+    create: (a, b, c, d) => ga("create", a, b, c, d),
+    getAll: () => Array.from(trackers.values()),
+    getByName: name => trackers.get(name),
+    loaded: true,
+    remove: t => ga("remove", t),
+  });
+
+  // Process any GA command queue the site pre-declares (bug 1736850)
+  const q = window[window.GoogleAnalyticsObject || "ga"]?.q;
+  window[window.GoogleAnalyticsObject || "ga"] = ga;
+
+  if (Array.isArray(q)) {
+    const push = o => {
+      ga(...o);
+      return true;
+    };
+    q.push = push;
+    q.forEach(o => push(o));
+  }
+
+  // Also process the Google Tag Manager dataLayer (bug 1713688)
+  const dl = window.dataLayer;
+
+  if (Array.isArray(dl) && !dl.find(e => e["gtm.start"])) {
+    const push = function (o) {
+      setTimeout(() => run(o?.eventCallback), 1);
+      return true;
+    };
+    dl.push = push;
+    dl.forEach(o => push(o));
+  }
+
+  // Run dataLayer.hide.end to handle asynchide (bug 1628151)
+  run(window.dataLayer?.hide?.end);
+}
+
+if (!window?.gaplugins?.Linker) {
+  window.gaplugins = window.gaplugins || {};
+  window.gaplugins.Linker = class {
+    autoLink() {}
+    decorate(url) {
+      return url;
+    }
+    passthrough() {}
+  };
+}
diff --git a/browser/extensions/webcompat/shims/google-analytics-ecommerce-plugin.js b/browser/extensions/webcompat/shims/google-analytics-ecommerce-plugin.js
new file mode 100644
index 0000000000..60b49df120
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-analytics-ecommerce-plugin.js
@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+if (!window.gaplugins) {
+  window.gaplugins = {};
+}
+
+if (!window.gaplugins.EC) {
+  window.gaplugins.EC = () => {};
+}
diff --git a/browser/extensions/webcompat/shims/google-analytics-legacy.js b/browser/extensions/webcompat/shims/google-analytics-legacy.js
new file mode 100644
index 0000000000..da1a638e12
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-analytics-legacy.js
@@ -0,0 +1,137 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// based on https://github.com/gorhill/uBlock/blob/6f49e079db0262e669b70f4169924f796ac8db7c/src/web_accessible_resources/google-analytics_ga.js
+
+"use strict";
+
+if (!window._gaq) {
+  function noopfn() {}
+
+  const gaq = {
+    Na: noopfn,
+    O: noopfn,
+    Sa: noopfn,
+    Ta: noopfn,
+    Va: noopfn,
+    _createAsyncTracker: noopfn,
+    _getAsyncTracker: noopfn,
+    _getPlugin: noopfn,
+    push: a => {
+      if (typeof a === "function") {
+        a();
+        return;
+      }
+      if (!Array.isArray(a)) {
+        return;
+      }
+      if (
+        typeof a[0] === "string" &&
+        /(^|\.)_link$/.test(a[0]) &&
+        typeof a[1] === "string"
+      ) {
+        window.location.assign(a[1]);
+      }
+      if (
+        a[0] === "_set" &&
+        a[1] === "hitCallback" &&
+        typeof a[2] === "function"
+      ) {
+        a[2]();
+      }
+    },
+  };
+
+  const tracker = {
+    _addIgnoredOrganic: noopfn,
+    _addIgnoredRef: noopfn,
+    _addItem: noopfn,
+    _addOrganic: noopfn,
+    _addTrans: noopfn,
+    _clearIgnoredOrganic: noopfn,
+    _clearIgnoredRef: noopfn,
+    _clearOrganic: noopfn,
+    _cookiePathCopy: noopfn,
+    _deleteCustomVar: noopfn,
+    _getName: noopfn,
+    _setAccount: noopfn,
+    _getAccount: noopfn,
+    _getClientInfo: noopfn,
+    _getDetectFlash: noopfn,
+    _getDetectTitle: noopfn,
+    _getLinkerUrl: a => a,
+    _getLocalGifPath: noopfn,
+    _getServiceMode: noopfn,
+    _getVersion: noopfn,
+    _getVisitorCustomVar: noopfn,
+    _initData: noopfn,
+    _link: noopfn,
+    _linkByPost: noopfn,
+    _setAllowAnchor: noopfn,
+    _setAllowHash: noopfn,
+    _setAllowLinker: noopfn,
+    _setCampContentKey: noopfn,
+    _setCampMediumKey: noopfn,
+    _setCampNameKey: noopfn,
+    _setCampNOKey: noopfn,
+    _setCampSourceKey: noopfn,
+    _setCampTermKey: noopfn,
+    _setCampaignCookieTimeout: noopfn,
+    _setCampaignTrack: noopfn,
+    _setClientInfo: noopfn,
+    _setCookiePath: noopfn,
+    _setCookiePersistence: noopfn,
+    _setCookieTimeout: noopfn,
+    _setCustomVar: noopfn,
+    _setDetectFlash: noopfn,
+    _setDetectTitle: noopfn,
+    _setDomainName: noopfn,
+    _setLocalGifPath: noopfn,
+    _setLocalRemoteServerMode: noopfn,
+    _setLocalServerMode: noopfn,
+    _setReferrerOverride: noopfn,
+    _setRemoteServerMode: noopfn,
+    _setSampleRate: noopfn,
+    _setSessionTimeout: noopfn,
+    _setSiteSpeedSampleRate: noopfn,
+    _setSessionCookieTimeout: noopfn,
+    _setVar: noopfn,
+    _setVisitorCookieTimeout: noopfn,
+    _trackEvent: noopfn,
+    _trackPageLoadTime: noopfn,
+    _trackPageview: noopfn,
+    _trackSocial: noopfn,
+    _trackTiming: noopfn,
+    _trackTrans: noopfn,
+    _visitCode: noopfn,
+  };
+
+  const gat = {
+    _anonymizeIP: noopfn,
+    _createTracker: noopfn,
+    _forceSSL: noopfn,
+    _getPlugin: noopfn,
+    _getTracker: () => tracker,
+    _getTrackerByName: () => tracker,
+    _getTrackers: noopfn,
+    aa: noopfn,
+    ab: noopfn,
+    hb: noopfn,
+    la: noopfn,
+    oa: noopfn,
+    pa: noopfn,
+    u: noopfn,
+  };
+
+  window._gat = gat;
+
+  const aa = window._gaq || [];
+  if (Array.isArray(aa)) {
+    while (aa[0]) {
+      gaq.push(aa.shift());
+    }
+  }
+
+  window._gaq = gaq.qf = gaq;
+}
diff --git a/browser/extensions/webcompat/shims/google-ima.js b/browser/extensions/webcompat/shims/google-ima.js
new file mode 100644
index 0000000000..1f5e56239d
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-ima.js
@@ -0,0 +1,620 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Bug 1713690 - Shim Google Interactive Media Ads ima3.js
+ *
+ * Many sites use ima3.js for ad bidding and placement, often in conjunction
+ * with Google Publisher Tags, Prebid.js and/or other scripts. This shim
+ * provides a stubbed-out version of the API which helps work around related
+ * site breakage, such as black bxoes where videos ought to be placed.
+ */
+
+if (!window.google?.ima?.VERSION) {
+  const VERSION = "3.517.2";
+
+  const CheckCanAutoplay = (function () {
+    // Sourced from: https://searchfox.org/mozilla-central/source/dom/media/gtest/negative_duration.mp4
+    const TEST_VIDEO = new Blob(
+      [
+        new Uint32Array([
+          469762048, 1887007846, 1752392036, 0, 913273705, 1717987696,
+          828601953, -1878917120, 1987014509, 1811939328, 1684567661, 0, 0, 0,
+          -402456576, 0, 256, 1, 0, 0, 256, 0, 0, 0, 256, 0, 0, 0, 64, 0, 0, 0,
+          0, 0, 0, 33554432, -201261056, 1801548404, 1744830464, 1684564852,
+          251658241, 0, 0, 0, 0, 16777216, 0, -1, -1, 0, 0, 0, 0, 256, 0, 0, 0,
+          256, 0, 0, 0, 64, 5, 53250, -2080309248, 1634296941, 738197504,
+          1684563053, 1, 0, 0, 0, 0, -2137614336, -1, -1, 50261, 754974720,
+          1919706216, 0, 0, 1701079414, 0, 0, 0, 1701079382, 1851869295,
+          1919249508, 16777216, 1852402979, 102, 1752004116, 100, 1, 0, 0,
+          1852400676, 102, 1701995548, 102, 0, 1, 1819440396, 32, 1, 1651799011,
+          108, 1937011607, 100, 0, 1, 1668702599, 49, 0, 1, 0, 0, 0, 33555712,
+          4718800, 4718592, 0, 65536, 0, 0, 0, 0, 0, 0, 0, 0, 16776984,
+          1630601216, 21193590, -14745500, 1729626337, -1407254428, 89161945,
+          1049019, 9453056, -251611125, 27269507, -379058688, -1329024392,
+          268435456, 1937011827, 0, 0, 268435456, 1668510835, 0, 0, 335544320,
+          2054386803, 0, 0, 0, 268435456, 1868788851, 0, 0, 671088640,
+          2019915373, 536870912, 2019914356, 0, 16777216, 16777216, 0, 0, 0,
+        ]),
+      ],
+      { type: "video/mp4" }
+    );
+
+    let testVideo = undefined;
+
+    return function () {
+      if (!testVideo) {
+        testVideo = document.createElement("video");
+        testVideo.style =
+          "position:absolute; width:0; height:0; left:0; right:0; z-index:-1; border:0";
+        testVideo.setAttribute("muted", "muted");
+        testVideo.setAttribute("playsinline", "playsinline");
+        testVideo.src = URL.createObjectURL(TEST_VIDEO);
+        document.body.appendChild(testVideo);
+      }
+      return testVideo.play();
+    };
+  })();
+
+  let ima = {};
+
+  class AdDisplayContainer {
+    destroy() {}
+    initialize() {}
+  }
+
+  class ImaSdkSettings {
+    #c = true;
+    #f = {};
+    #i = false;
+    #l = "";
+    #p = "";
+    #r = 0;
+    #t = "";
+    #v = "";
+    getCompanionBackfill() {}
+    getDisableCustomPlaybackForIOS10Plus() {
+      return this.#i;
+    }
+    getFeatureFlags() {
+      return this.#f;
+    }
+    getLocale() {
+      return this.#l;
+    }
+    getNumRedirects() {
+      return this.#r;
+    }
+    getPlayerType() {
+      return this.#t;
+    }
+    getPlayerVersion() {
+      return this.#v;
+    }
+    getPpid() {
+      return this.#p;
+    }
+    isCookiesEnabled() {
+      return this.#c;
+    }
+    setAutoPlayAdBreaks() {}
+    setCompanionBackfill() {}
+    setCookiesEnabled(c) {
+      this.#c = !!c;
+    }
+    setDisableCustomPlaybackForIOS10Plus(i) {
+      this.#i = !!i;
+    }
+    setFeatureFlags(f) {
+      this.#f = f;
+    }
+    setLocale(l) {
+      this.#l = l;
+    }
+    setNumRedirects(r) {
+      this.#r = r;
+    }
+    setPlayerType(t) {
+      this.#t = t;
+    }
+    setPlayerVersion(v) {
+      this.#v = v;
+    }
+    setPpid(p) {
+      this.#p = p;
+    }
+    setSessionId(s) {}
+    setVpaidAllowed(a) {}
+    setVpaidMode(m) {}
+  }
+  ImaSdkSettings.CompanionBackfillMode = {
+    ALWAYS: "always",
+    ON_MASTER_AD: "on_master_ad",
+  };
+  ImaSdkSettings.VpaidMode = {
+    DISABLED: 0,
+    ENABLED: 1,
+    INSECURE: 2,
+  };
+
+  class EventHandler {
+    #listeners = new Map();
+
+    _dispatch(e) {
+      const listeners = this.#listeners.get(e.type) || [];
+      for (const listener of Array.from(listeners)) {
+        try {
+          listener(e);
+        } catch (r) {
+          console.error(r);
+        }
+      }
+    }
+
+    addEventListener(t, c) {
+      if (!this.#listeners.has(t)) {
+        this.#listeners.set(t, new Set());
+      }
+      this.#listeners.get(t).add(c);
+    }
+
+    removeEventListener(t, c) {
+      this.#listeners.get(t)?.delete(c);
+    }
+  }
+
+  class AdsLoader extends EventHandler {
+    #settings = new ImaSdkSettings();
+    contentComplete() {}
+    destroy() {}
+    getSettings() {
+      return this.#settings;
+    }
+    getVersion() {
+      return VERSION;
+    }
+    requestAds(r, c) {
+      // If autoplay is disabled and the page is trying to autoplay a tracking
+      // ad, then IMA fails with an error, and the page is expected to request
+      // ads again later when the user clicks to play.
+      CheckCanAutoplay().then(
+        () => {
+          const { ADS_MANAGER_LOADED } = AdsManagerLoadedEvent.Type;
+          this._dispatch(new ima.AdsManagerLoadedEvent(ADS_MANAGER_LOADED));
+        },
+        () => {
+          const e = new ima.AdError(
+            "adPlayError",
+            1205,
+            1205,
+            "The browser prevented playback initiated without user interaction."
+          );
+          this._dispatch(new ima.AdErrorEvent(e));
+        }
+      );
+    }
+  }
+
+  class AdsManager extends EventHandler {
+    #volume = 1;
+    collapse() {}
+    configureAdsManager() {}
+    destroy() {}
+    discardAdBreak() {}
+    expand() {}
+    focus() {}
+    getAdSkippableState() {
+      return false;
+    }
+    getCuePoints() {
+      return [0];
+    }
+    getCurrentAd() {
+      return currentAd;
+    }
+    getCurrentAdCuePoints() {
+      return [];
+    }
+    getRemainingTime() {
+      return 0;
+    }
+    getVolume() {
+      return this.#volume;
+    }
+    init(w, h, m, e) {}
+    isCustomClickTrackingUsed() {
+      return false;
+    }
+    isCustomPlaybackUsed() {
+      return false;
+    }
+    pause() {}
+    requestNextAdBreak() {}
+    resize(w, h, m) {}
+    resume() {}
+    setVolume(v) {
+      this.#volume = v;
+    }
+    skip() {}
+    start() {
+      requestAnimationFrame(() => {
+        for (const type of [
+          AdEvent.Type.LOADED,
+          AdEvent.Type.STARTED,
+          AdEvent.Type.CONTENT_RESUME_REQUESTED,
+          AdEvent.Type.AD_BUFFERING,
+          AdEvent.Type.FIRST_QUARTILE,
+          AdEvent.Type.MIDPOINT,
+          AdEvent.Type.THIRD_QUARTILE,
+          AdEvent.Type.COMPLETE,
+          AdEvent.Type.ALL_ADS_COMPLETED,
+        ]) {
+          try {
+            this._dispatch(new ima.AdEvent(type));
+          } catch (e) {
+            console.error(e);
+          }
+        }
+      });
+    }
+    stop() {}
+    updateAdsRenderingSettings(s) {}
+  }
+
+  class AdsRenderingSettings {}
+
+  class AdsRequest {
+    setAdWillAutoPlay() {}
+    setAdWillPlayMuted() {}
+    setContinuousPlayback() {}
+  }
+
+  class AdPodInfo {
+    getAdPosition() {
+      return 1;
+    }
+    getIsBumper() {
+      return false;
+    }
+    getMaxDuration() {
+      return -1;
+    }
+    getPodIndex() {
+      return 1;
+    }
+    getTimeOffset() {
+      return 0;
+    }
+    getTotalAds() {
+      return 1;
+    }
+  }
+
+  class Ad {
+    _pi = new AdPodInfo();
+    getAdId() {
+      return "";
+    }
+    getAdPodInfo() {
+      return this._pi;
+    }
+    getAdSystem() {
+      return "";
+    }
+    getAdvertiserName() {
+      return "";
+    }
+    getApiFramework() {
+      return null;
+    }
+    getCompanionAds() {
+      return [];
+    }
+    getContentType() {
+      return "";
+    }
+    getCreativeAdId() {
+      return "";
+    }
+    getCreativeId() {
+      return "";
+    }
+    getDealId() {
+      return "";
+    }
+    getDescription() {
+      return "";
+    }
+    getDuration() {
+      return 8.5;
+    }
+    getHeight() {
+      return 0;
+    }
+    getMediaUrl() {
+      return null;
+    }
+    getMinSuggestedDuration() {
+      return -2;
+    }
+    getSkipTimeOffset() {
+      return -1;
+    }
+    getSurveyUrl() {
+      return null;
+    }
+    getTitle() {
+      return "";
+    }
+    getTraffickingParameters() {
+      return {};
+    }
+    getTraffickingParametersString() {
+      return "";
+    }
+    getUiElements() {
+      return [""];
+    }
+    getUniversalAdIdRegistry() {
+      return "unknown";
+    }
+    getUniversalAdIds() {
+      return [""];
+    }
+    getUniversalAdIdValue() {
+      return "unknown";
+    }
+    getVastMediaBitrate() {
+      return 0;
+    }
+    getVastMediaHeight() {
+      return 0;
+    }
+    getVastMediaWidth() {
+      return 0;
+    }
+    getWidth() {
+      return 0;
+    }
+    getWrapperAdIds() {
+      return [""];
+    }
+    getWrapperAdSystems() {
+      return [""];
+    }
+    getWrapperCreativeIds() {
+      return [""];
+    }
+    isLinear() {
+      return true;
+    }
+    isSkippable() {
+      return true;
+    }
+  }
+
+  class CompanionAd {
+    getAdSlotId() {
+      return "";
+    }
+    getContent() {
+      return "";
+    }
+    getContentType() {
+      return "";
+    }
+    getHeight() {
+      return 1;
+    }
+    getWidth() {
+      return 1;
+    }
+  }
+
+  class AdError {
+    #errorCode = -1;
+    #message = "";
+    #type = "";
+    #vastErrorCode = -1;
+    constructor(type, code, vast, message) {
+      this.#errorCode = code;
+      this.#message = message;
+      this.#type = type;
+      this.#vastErrorCode = vast;
+    }
+    getErrorCode() {
+      return this.#errorCode;
+    }
+    getInnerError() {}
+    getMessage() {
+      return this.#message;
+    }
+    getType() {
+      return this.#type;
+    }
+    getVastErrorCode() {
+      return this.#vastErrorCode;
+    }
+    toString() {
+      return `AdError ${this.#errorCode}: ${this.#message}`;
+    }
+  }
+  AdError.ErrorCode = {};
+  AdError.Type = {};
+
+  const isEngadget = () => {
+    try {
+      for (const ctx of Object.values(window.vidible._getContexts())) {
+        if (ctx.getPlayer()?.div?.innerHTML.includes("www.engadget.com")) {
+          return true;
+        }
+      }
+    } catch (_) {}
+    return false;
+  };
+
+  const currentAd = isEngadget() ? undefined : new Ad();
+
+  class AdEvent {
+    constructor(type) {
+      this.type = type;
+    }
+    getAd() {
+      return currentAd;
+    }
+    getAdData() {
+      return {};
+    }
+  }
+  AdEvent.Type = {
+    AD_BREAK_READY: "adBreakReady",
+    AD_BUFFERING: "adBuffering",
+    AD_CAN_PLAY: "adCanPlay",
+    AD_METADATA: "adMetadata",
+    AD_PROGRESS: "adProgress",
+    ALL_ADS_COMPLETED: "allAdsCompleted",
+    CLICK: "click",
+    COMPLETE: "complete",
+    CONTENT_PAUSE_REQUESTED: "contentPauseRequested",
+    CONTENT_RESUME_REQUESTED: "contentResumeRequested",
+    DURATION_CHANGE: "durationChange",
+    EXPANDED_CHANGED: "expandedChanged",
+    FIRST_QUARTILE: "firstQuartile",
+    IMPRESSION: "impression",
+    INTERACTION: "interaction",
+    LINEAR_CHANGE: "linearChange",
+    LINEAR_CHANGED: "linearChanged",
+    LOADED: "loaded",
+    LOG: "log",
+    MIDPOINT: "midpoint",
+    PAUSED: "pause",
+    RESUMED: "resume",
+    SKIPPABLE_STATE_CHANGED: "skippableStateChanged",
+    SKIPPED: "skip",
+    STARTED: "start",
+    THIRD_QUARTILE: "thirdQuartile",
+    USER_CLOSE: "userClose",
+    VIDEO_CLICKED: "videoClicked",
+    VIDEO_ICON_CLICKED: "videoIconClicked",
+    VIEWABLE_IMPRESSION: "viewable_impression",
+    VOLUME_CHANGED: "volumeChange",
+    VOLUME_MUTED: "mute",
+  };
+
+  class AdErrorEvent {
+    type = "adError";
+    #error = "";
+    constructor(error) {
+      this.#error = error;
+    }
+    getError() {
+      return this.#error;
+    }
+    getUserRequestContext() {
+      return {};
+    }
+  }
+  AdErrorEvent.Type = {
+    AD_ERROR: "adError",
+  };
+
+  const manager = new AdsManager();
+
+  class AdsManagerLoadedEvent {
+    constructor(type) {
+      this.type = type;
+    }
+    getAdsManager() {
+      return manager;
+    }
+    getUserRequestContext() {
+      return {};
+    }
+  }
+  AdsManagerLoadedEvent.Type = {
+    ADS_MANAGER_LOADED: "adsManagerLoaded",
+  };
+
+  class CustomContentLoadedEvent {}
+  CustomContentLoadedEvent.Type = {
+    CUSTOM_CONTENT_LOADED: "deprecated-event",
+  };
+
+  class CompanionAdSelectionSettings {}
+  CompanionAdSelectionSettings.CreativeType = {
+    ALL: "All",
+    FLASH: "Flash",
+    IMAGE: "Image",
+  };
+  CompanionAdSelectionSettings.ResourceType = {
+    ALL: "All",
+    HTML: "Html",
+    IFRAME: "IFrame",
+    STATIC: "Static",
+  };
+  CompanionAdSelectionSettings.SizeCriteria = {
+    IGNORE: "IgnoreSize",
+    SELECT_EXACT_MATCH: "SelectExactMatch",
+    SELECT_NEAR_MATCH: "SelectNearMatch",
+  };
+
+  class AdCuePoints {
+    getCuePoints() {
+      return [];
+    }
+  }
+
+  class AdProgressData {}
+
+  class UniversalAdIdInfo {
+    getAdIdRegistry() {
+      return "";
+    }
+    getAdIsValue() {
+      return "";
+    }
+  }
+
+  Object.assign(ima, {
+    AdCuePoints,
+    AdDisplayContainer,
+    AdError,
+    AdErrorEvent,
+    AdEvent,
+    AdPodInfo,
+    AdProgressData,
+    AdsLoader,
+    AdsManager: manager,
+    AdsManagerLoadedEvent,
+    AdsRenderingSettings,
+    AdsRequest,
+    CompanionAd,
+    CompanionAdSelectionSettings,
+    CustomContentLoadedEvent,
+    gptProxyInstance: {},
+    ImaSdkSettings,
+    OmidAccessMode: {
+      DOMAIN: "domain",
+      FULL: "full",
+      LIMITED: "limited",
+    },
+    settings: new ImaSdkSettings(),
+    UiElements: {
+      AD_ATTRIBUTION: "adAttribution",
+      COUNTDOWN: "countdown",
+    },
+    UniversalAdIdInfo,
+    VERSION,
+    ViewMode: {
+      FULLSCREEN: "fullscreen",
+      NORMAL: "normal",
+    },
+  });
+
+  if (!window.google) {
+    window.google = {};
+  }
+
+  window.google.ima = ima;
+}
diff --git a/browser/extensions/webcompat/shims/google-page-ad.js b/browser/extensions/webcompat/shims/google-page-ad.js
new file mode 100644
index 0000000000..42f3a0fca5
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-page-ad.js
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713692 - Shim Google Page Ad conversion tracker
+ *
+ * This shim stubs out the simple API for converstion tracking with
+ * Google Page Ad, mitigating major breakage on pages which presume
+ * the API will always successfully load.
+ */
+
+if (!window.google_trackConversion) {
+  window.google_trackConversion = () => {};
+}
diff --git a/browser/extensions/webcompat/shims/google-publisher-tags.js b/browser/extensions/webcompat/shims/google-publisher-tags.js
new file mode 100644
index 0000000000..e5174d3244
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-publisher-tags.js
@@ -0,0 +1,509 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713685 - Shim Google Publisher Tags
+ *
+ * Many sites rely on googletag to place content or drive ad bidding,
+ * and will experience major breakage if it is blocked. This shim provides
+ * enough of the API's frame To mitigate much of that breakage.
+ */
+
+if (window.googletag?.apiReady === undefined) {
+  const version = "2021050601";
+
+  const noopthisfn = function () {
+    return this;
+  };
+
+  const slots = new Map();
+  const slotsById = new Map();
+  const slotsPerPath = new Map();
+  const slotCreatives = new Map();
+  const usedCreatives = new Map();
+  const fetchedSlots = new Set();
+  const eventCallbacks = new Map();
+
+  const fireSlotEvent = (name, slot) => {
+    return new Promise(resolve => {
+      requestAnimationFrame(() => {
+        const size = [0, 0];
+        for (const cb of eventCallbacks.get(name) || []) {
+          cb({ isEmpty: true, size, slot });
+        }
+        resolve();
+      });
+    });
+  };
+
+  const recreateIframeForSlot = slot => {
+    const eid = `google_ads_iframe_${slot.getId()}`;
+    document.getElementById(eid)?.remove();
+    const node = document.getElementById(slot.getSlotElementId());
+    if (node) {
+      const f = document.createElement("iframe");
+      f.id = eid;
+      f.srcdoc = "<body></body>";
+      f.style =
+        "position:absolute; width:0; height:0; left:0; right:0; z-index:-1; border:0";
+      f.setAttribute("width", 0);
+      f.setAttribute("height", 0);
+      node.appendChild(f);
+    }
+  };
+
+  const emptySlotElement = slot => {
+    const node = document.getElementById(slot.getSlotElementId());
+    while (node?.lastChild) {
+      node.lastChild.remove();
+    }
+  };
+
+  const SizeMapping = class extends Array {
+    getCreatives() {
+      const { clientWidth, clientHeight } = document.documentElement;
+      for (const [size, creatives] of this) {
+        if (clientWidth >= size[0] && clientHeight >= size[1]) {
+          return creatives;
+        }
+      }
+      return [];
+    }
+  };
+
+  const fetchSlot = slot => {
+    if (!slot) {
+      return;
+    }
+
+    const id = slot.getSlotElementId();
+
+    const node = document.getElementById(id);
+    if (!node) {
+      return;
+    }
+
+    let creatives = slotCreatives.get(id);
+    if (creatives instanceof SizeMapping) {
+      creatives = creatives.getCreatives();
+    }
+
+    if (!creatives?.length) {
+      return;
+    }
+
+    for (const creative of creatives) {
+      if (usedCreatives.has(creative)) {
+        return;
+      }
+    }
+
+    const creative = creatives[0];
+    usedCreatives.set(creative, slot);
+    fetchedSlots.add(id);
+  };
+
+  const displaySlot = async slot => {
+    if (!slot) {
+      return;
+    }
+
+    const id = slot.getSlotElementId();
+    if (!document.getElementById(id)) {
+      return;
+    }
+
+    if (!fetchedSlots.has(id)) {
+      fetchSlot(slot);
+    }
+
+    const parent = document.getElementById(id);
+    if (parent) {
+      parent.appendChild(document.createElement("div"));
+    }
+
+    emptySlotElement(slot);
+    recreateIframeForSlot(slot);
+    await fireSlotEvent("slotRenderEnded", slot);
+    await fireSlotEvent("slotRequested", slot);
+    await fireSlotEvent("slotResponseReceived", slot);
+    await fireSlotEvent("slotOnload", slot);
+    await fireSlotEvent("impressionViewable", slot);
+  };
+
+  const addEventListener = function (name, listener) {
+    if (!eventCallbacks.has(name)) {
+      eventCallbacks.set(name, new Set());
+    }
+    eventCallbacks.get(name).add(listener);
+    return this;
+  };
+
+  const removeEventListener = function (name, listener) {
+    if (eventCallbacks.has(name)) {
+      return eventCallbacks.get(name).delete(listener);
+    }
+    return false;
+  };
+
+  const companionAdsService = {
+    addEventListener,
+    enable() {},
+    fillSlot() {},
+    getAttributeKeys: () => [],
+    getDisplayAdsCorrelator: () => "",
+    getName: () => "companion_ads",
+    getSlotIdMap: () => {
+      return {};
+    },
+    getSlots: () => [],
+    getVideoStreamCorrelator() {},
+    isRoadblockingSupported: () => false,
+    isSlotAPersistentRoadblock: () => false,
+    notifyUnfilledSlots() {},
+    onImplementationLoaded() {},
+    refreshAllSlots() {
+      for (const slot of slotsById.values()) {
+        fetchSlot(slot);
+        displaySlot(slot);
+      }
+    },
+    removeEventListener,
+    set() {},
+    setRefreshUnfilledSlots() {},
+    setVideoSession() {},
+    slotRenderEnded() {},
+  };
+
+  const contentService = {
+    addEventListener,
+    setContent() {},
+    removeEventListener,
+  };
+
+  const getTargetingValue = v => {
+    if (typeof v === "string") {
+      return [v];
+    }
+    try {
+      return [Array.prototype.flat.call(v)[0]];
+    } catch (_) {}
+    return [];
+  };
+
+  const updateTargeting = (targeting, map) => {
+    if (typeof map === "object") {
+      const entries = Object.entries(map || {});
+      for (const [k, v] of entries) {
+        targeting.set(k, getTargetingValue(v));
+      }
+    }
+  };
+
+  const defineSlot = (adUnitPath, creatives, opt_div) => {
+    if (slotsById.has(opt_div)) {
+      document.getElementById(opt_div)?.remove();
+      return slotsById.get(opt_div);
+    }
+    const attributes = new Map();
+    const targeting = new Map();
+    const exclusions = new Set();
+    const response = {
+      advertiserId: undefined,
+      campaignId: undefined,
+      creativeId: undefined,
+      creativeTemplateId: undefined,
+      lineItemId: undefined,
+    };
+    const sizes = [
+      {
+        getHeight: () => 2,
+        getWidth: () => 2,
+      },
+    ];
+    const num = (slotsPerPath.get(adUnitPath) || 0) + 1;
+    slotsPerPath.set(adUnitPath, num);
+    const id = `${adUnitPath}_${num}`;
+    let clickUrl = "";
+    let collapseEmptyDiv = null;
+    let services = new Set();
+    const slot = {
+      addService(e) {
+        services.add(e);
+        return slot;
+      },
+      clearCategoryExclusions: noopthisfn,
+      clearTargeting(k) {
+        if (k === undefined) {
+          targeting.clear();
+        } else {
+          targeting.delete(k);
+        }
+      },
+      defineSizeMapping(mapping) {
+        slotCreatives.set(opt_div, mapping);
+        return this;
+      },
+      get: k => attributes.get(k),
+      getAdUnitPath: () => adUnitPath,
+      getAttributeKeys: () => Array.from(attributes.keys()),
+      getCategoryExclusions: () => Array.from(exclusions),
+      getClickUrl: () => clickUrl,
+      getCollapseEmptyDiv: () => collapseEmptyDiv,
+      getContentUrl: () => "",
+      getDivStartsCollapsed: () => null,
+      getDomId: () => opt_div,
+      getEscapedQemQueryId: () => "",
+      getFirstLook: () => 0,
+      getId: () => id,
+      getHtml: () => "",
+      getName: () => id,
+      getOutOfPage: () => false,
+      getResponseInformation: () => response,
+      getServices: () => Array.from(services),
+      getSizes: () => sizes,
+      getSlotElementId: () => opt_div,
+      getSlotId: () => slot,
+      getTargeting: k => targeting.get(k) || gTargeting.get(k) || [],
+      getTargetingKeys: () =>
+        Array.from(
+          new Set(Array.of(...gTargeting.keys(), ...targeting.keys()))
+        ),
+      getTargetingMap: () =>
+        Object.assign(
+          Object.fromEntries(gTargeting.entries()),
+          Object.fromEntries(targeting.entries())
+        ),
+      set(k, v) {
+        attributes.set(k, v);
+        return slot;
+      },
+      setCategoryExclusion(e) {
+        exclusions.add(e);
+        return slot;
+      },
+      setClickUrl(u) {
+        clickUrl = u;
+        return slot;
+      },
+      setCollapseEmptyDiv(v) {
+        collapseEmptyDiv = !!v;
+        return slot;
+      },
+      setSafeFrameConfig: noopthisfn,
+      setTagForChildDirectedTreatment: noopthisfn,
+      setTargeting(k, v) {
+        targeting.set(k, getTargetingValue(v));
+        return slot;
+      },
+      toString: () => id,
+      updateTargetingFromMap(map) {
+        updateTargeting(targeting, map);
+        return slot;
+      },
+    };
+    slots.set(adUnitPath, slot);
+    slotsById.set(opt_div, slot);
+    slotCreatives.set(opt_div, creatives);
+    return slot;
+  };
+
+  let initialLoadDisabled = false;
+
+  const gTargeting = new Map();
+  const gAttributes = new Map();
+
+  let imaContent = { vid: "", cmsid: "" };
+  let videoContent = { vid: "", cmsid: "" };
+
+  const pubadsService = {
+    addEventListener,
+    clear() {},
+    clearCategoryExclusions: noopthisfn,
+    clearTagForChildDirectedTreatment: noopthisfn,
+    clearTargeting(k) {
+      if (k === undefined) {
+        gTargeting.clear();
+      } else {
+        gTargeting.delete(k);
+      }
+    },
+    collapseEmptyDivs() {},
+    defineOutOfPagePassback: (a, o) => defineSlot(a, 0, o),
+    definePassback: (a, s, o) => defineSlot(a, s, o),
+    disableInitialLoad() {
+      initialLoadDisabled = true;
+      return this;
+    },
+    display(adUnitPath, sizes, opt_div) {
+      const slot = defineSlot(adUnitPath, sizes, opt_div);
+      displaySlot(slot);
+    },
+    enable() {},
+    enableAsyncRendering() {},
+    enableLazyLoad() {},
+    enableSingleRequest() {},
+    enableSyncRendering() {},
+    enableVideoAds() {},
+    forceExperiment() {},
+    get: k => gAttributes.get(k),
+    getAttributeKeys: () => Array.from(gAttributes.keys()),
+    getCorrelator() {},
+    getImaContent: () => imaContent,
+    getName: () => "publisher_ads",
+    getSlots: () => Array.from(slots.values()),
+    getSlotIdMap() {
+      const map = {};
+      slots.values().forEach(s => {
+        map[s.getId()] = s;
+      });
+      return map;
+    },
+    getTagSessionCorrelator() {},
+    getTargeting: k => gTargeting.get(k) || [],
+    getTargetingKeys: () => Array.from(gTargeting.keys()),
+    getTargetingMap: () => Object.fromEntries(gTargeting.entries()),
+    getVersion: () => version,
+    getVideoContent: () => videoContent,
+    isInitialLoadDisabled: () => initialLoadDisabled,
+    isSRA: () => false,
+    markAsAmp() {},
+    refresh(slts) {
+      if (!slts) {
+        slts = slots.values();
+      } else if (!Array.isArray(slts)) {
+        slts = [slts];
+      }
+      for (const slot of slts) {
+        if (slot) {
+          try {
+            fetchSlot(slot);
+            displaySlot(slot);
+          } catch (e) {
+            console.error(e);
+          }
+        }
+      }
+    },
+    removeEventListener,
+    set(k, v) {
+      gAttributes[k] = v;
+      return this;
+    },
+    setCategoryExclusion: noopthisfn,
+    setCentering() {},
+    setCookieOptions: noopthisfn,
+    setCorrelator: noopthisfn,
+    setForceSafeFrame: noopthisfn,
+    setImaContent(vid, cmsid) {
+      imaContent = { vid, cmsid };
+      return this;
+    },
+    setLocation: noopthisfn,
+    setPrivacySettings: noopthisfn,
+    setPublisherProvidedId: noopthisfn,
+    setRequestNonPersonalizedAds: noopthisfn,
+    setSafeFrameConfig: noopthisfn,
+    setTagForChildDirectedTreatment: noopthisfn,
+    setTagForUnderAgeOfConsent: noopthisfn,
+    setTargeting(k, v) {
+      gTargeting.set(k, getTargetingValue(v));
+      return this;
+    },
+    setVideoContent(vid, cmsid) {
+      videoContent = { vid, cmsid };
+      return this;
+    },
+    updateCorrelator() {},
+    updateTargetingFromMap(map) {
+      updateTargeting(gTargeting, map);
+      return this;
+    },
+  };
+
+  const SizeMappingBuilder = class {
+    #mapping;
+    constructor() {
+      this.#mapping = new SizeMapping();
+    }
+    addSize(size, creatives) {
+      if (
+        size !== "fluid" &&
+        (!Array.isArray(size) || isNaN(size[0]) || isNaN(size[1]))
+      ) {
+        this.#mapping = null;
+      } else {
+        this.#mapping?.push([size, creatives]);
+      }
+      return this;
+    }
+    build() {
+      return this.#mapping;
+    }
+  };
+
+  let gt = window.googletag;
+  if (!gt) {
+    gt = window.googletag = {};
+  }
+
+  Object.assign(gt, {
+    apiReady: true,
+    companionAds: () => companionAdsService,
+    content: () => contentService,
+    defineOutOfPageSlot: (a, o) => defineSlot(a, 0, o),
+    defineSlot: (a, s, o) => defineSlot(a, s, o),
+    destroySlots() {
+      slots.clear();
+      slotsById.clear();
+    },
+    disablePublisherConsole() {},
+    display(arg) {
+      let id;
+      if (arg?.getSlotElementId) {
+        id = arg.getSlotElementId();
+      } else if (arg?.nodeType) {
+        id = arg.id;
+      } else {
+        id = String(arg);
+      }
+      displaySlot(slotsById.get(id));
+    },
+    enableServices() {},
+    enums: {
+      OutOfPageFormat: {
+        BOTTOM_ANCHOR: 3,
+        INTERSTITIAL: 5,
+        REWARDED: 4,
+        TOP_ANCHOR: 2,
+      },
+    },
+    getVersion: () => version,
+    pubads: () => pubadsService,
+    pubadsReady: true,
+    setAdIframeTitle() {},
+    sizeMapping: () => new SizeMappingBuilder(),
+  });
+
+  const run = function (fn) {
+    if (typeof fn === "function") {
+      try {
+        fn.call(window);
+      } catch (e) {
+        console.error(e);
+      }
+    }
+  };
+
+  const cmds = gt.cmd || [];
+  const newCmd = [];
+  newCmd.push = run;
+  gt.cmd = newCmd;
+
+  for (const cmd of cmds) {
+    run(cmd);
+  }
+}
diff --git a/browser/extensions/webcompat/shims/google-safeframe.html b/browser/extensions/webcompat/shims/google-safeframe.html
new file mode 100644
index 0000000000..34bc1d242f
--- /dev/null
+++ b/browser/extensions/webcompat/shims/google-safeframe.html
@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  Bug 1713691 - Shim Google SafeFrame
+
+  Some sites will break if they cannot load a Google SafeFrame. This
+  shim provides a stand-in for the frame to mitigate that breakage.
+-->
+<html>
+  <head>
+    <meta charset="UTF-8" />
+    <title>SafeFrame Container</title>
+    <script>
+      try {
+        const F = /^([^;]+);(\d+);([\s\S]*)$/.exec(window.name);
+        window.name = "";
+        const P = window.document;
+        P.open("text/html", "replace");
+        P.write(F[3].substr(0, +F[2]));
+        P.close();
+      } catch (e) {
+        console.error(e);
+      }
+    </script>
+  </head>
+  <body></body>
+</html>
diff --git a/browser/extensions/webcompat/shims/history.js b/browser/extensions/webcompat/shims/history.js
new file mode 100644
index 0000000000..6fbd1fdedb
--- /dev/null
+++ b/browser/extensions/webcompat/shims/history.js
@@ -0,0 +1,54 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/*
+ * Bug 1624853 - Shim Storage Access API on history.com
+ *
+ * history.com uses Adobe as a necessary third party to authenticating
+ * with a TV provider. In order to accomodate this, we grant storage access
+ * to the Adobe domain via the Storage Access API when the login or logout
+ * buttons are clicked, then forward the click to continue as normal.
+ */
+
+console.warn(
+  `When using oauth, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1624853 for details.`
+);
+
+// Third-party origin we need to request storage access for.
+const STORAGE_ACCESS_ORIGIN = "https://sp.auth.adobe.com";
+
+document.documentElement.addEventListener(
+  "click",
+  e => {
+    const { target, isTrusted } = e;
+    if (!isTrusted) {
+      return;
+    }
+
+    const button = target.closest("a");
+    if (!button) {
+      return;
+    }
+
+    const buttonLink = button.href;
+    if (buttonLink?.startsWith("https://www.history.com/mvpd-auth")) {
+      button.disabled = true;
+      button.style.opacity = 0.5;
+      e.stopPropagation();
+      e.preventDefault();
+      document
+        .requestStorageAccessForOrigin(STORAGE_ACCESS_ORIGIN)
+        .then(() => {
+          target.click();
+        })
+        .catch(() => {
+          button.disabled = false;
+          button.style.opacity = 1.0;
+        });
+    }
+  },
+  true
+);
diff --git a/browser/extensions/webcompat/shims/iam.js b/browser/extensions/webcompat/shims/iam.js
new file mode 100644
index 0000000000..84dee0e484
--- /dev/null
+++ b/browser/extensions/webcompat/shims/iam.js
@@ -0,0 +1,39 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1761774 - Shim INFOnline IAM tracker
+ *
+ * Sites using IAM can break if it is blocked. This shim mitigates that
+ * breakage by loading a stand-in module.
+ */
+
+if (!window.iom?.c) {
+  window.iom = {
+    c: () => {},
+    consent: () => {},
+    count: () => {},
+    ct: () => {},
+    deloptout: () => {},
+    doo: () => {},
+    e: () => {},
+    event: () => {},
+    getInvitation: () => {},
+    getPlus: () => {},
+    gi: () => {},
+    gp: () => {},
+    h: () => {},
+    hybrid: () => {},
+    i: () => {},
+    init: () => {},
+    oi: () => {},
+    optin: () => {},
+    setMultiIdentifier: () => {},
+    setoptout: () => {},
+    smi: () => {},
+    soo: () => {},
+  };
+}
diff --git a/browser/extensions/webcompat/shims/iaspet.js b/browser/extensions/webcompat/shims/iaspet.js
new file mode 100644
index 0000000000..7e19dd52ad
--- /dev/null
+++ b/browser/extensions/webcompat/shims/iaspet.js
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713701 - Shim Integral Ad Science iaspet.js
+ *
+ * Some sites use iaspet to place content, often together with Google Publisher
+ * Tags. This shim prevents breakage when the script is blocked.
+ */
+
+if (!window.__iasPET?.VERSION) {
+  let queue = window?.__iasPET?.queue;
+  if (!Array.isArray(queue)) {
+    queue = [];
+  }
+
+  const response = JSON.stringify({
+    brandSafety: {},
+    slots: {},
+  });
+
+  function run(cmd) {
+    try {
+      cmd?.dataHandler?.(response);
+    } catch (_) {}
+  }
+
+  queue.push = run;
+
+  window.__iasPET = {
+    VERSION: "1.16.18",
+    queue,
+    sessionId: "",
+    setTargetingForAppNexus() {},
+    setTargetingForGPT() {},
+    start() {},
+  };
+
+  while (queue.length) {
+    run(queue.shift());
+  }
+}
diff --git a/browser/extensions/webcompat/shims/instagram.js b/browser/extensions/webcompat/shims/instagram.js
new file mode 100644
index 0000000000..5bf5014fdc
--- /dev/null
+++ b/browser/extensions/webcompat/shims/instagram.js
@@ -0,0 +1,55 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/*
+ * Bug 1804445 - instagram login broken with dFPI enabled
+ *
+ * Instagram login with Facebook account requires Facebook to have the storage
+ * access under Instagram. This shim adds a request for storage access for
+ * Facebook when the user tries to log in with a Facebook account.
+ */
+
+console.warn(
+  `When logging in, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1804445 for details.`
+);
+
+// Third-party origin we need to request storage access for.
+const STORAGE_ACCESS_ORIGIN = "https://www.facebook.com";
+
+document.documentElement.addEventListener(
+  "click",
+  e => {
+    const { target, isTrusted } = e;
+    if (!isTrusted) {
+      return;
+    }
+    const button = target.closest("button[type=button]");
+    if (!button) {
+      return;
+    }
+    const form = target.closest("#loginForm");
+    if (!form) {
+      return;
+    }
+
+    console.warn(
+      "Calling the Storage Access API on behalf of " + STORAGE_ACCESS_ORIGIN
+    );
+    button.disabled = true;
+    e.stopPropagation();
+    e.preventDefault();
+    document
+      .requestStorageAccessForOrigin(STORAGE_ACCESS_ORIGIN)
+      .then(() => {
+        button.disabled = false;
+        target.click();
+      })
+      .catch(() => {
+        button.disabled = false;
+      });
+  },
+  true
+);
diff --git a/browser/extensions/webcompat/shims/kinja.js b/browser/extensions/webcompat/shims/kinja.js
new file mode 100644
index 0000000000..d30425b42d
--- /dev/null
+++ b/browser/extensions/webcompat/shims/kinja.js
@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* globals exportFunction */
+
+"use strict";
+
+/**
+ * Kinja powered blogs rely on storage access to https://kinja.com to enable
+ * oauth with external providers. For dFPI, sites need to use the Storage Access
+ * API to gain first party storage access. This shim calls requestStorageAccess
+ * on behalf of the site when a user wants to log in via oauth.
+ */
+
+// Third-party origin we need to request storage access for.
+const STORAGE_ACCESS_ORIGIN = "https://kinja.com";
+
+// Prefix of the path opened in a new window when users click the oauth login
+// buttons.
+const OAUTH_PATH_PREFIX = "/oauthlogin?provider=";
+
+console.warn(
+  `When using oauth, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1656171 for details.`
+);
+
+// Overwrite the window.open method so we can detect oauth related popups.
+const origOpen = window.wrappedJSObject.open;
+Object.defineProperty(window.wrappedJSObject, "open", {
+  value: exportFunction((url, ...args) => {
+    // Filter oauth popups.
+    if (!url.startsWith(OAUTH_PATH_PREFIX)) {
+      return origOpen(url, ...args);
+    }
+    // Request storage access for Kinja.
+    document.requestStorageAccessForOrigin(STORAGE_ACCESS_ORIGIN).then(() => {
+      origOpen(url, ...args);
+    });
+    // We don't have the window object yet which window.open returns, since the
+    // sign-in flow is dependent on the async storage access request. This isn't
+    // a problem as long as the website does not consume it.
+    return null;
+  }, window),
+});
diff --git a/browser/extensions/webcompat/shims/live-test-shim.js b/browser/extensions/webcompat/shims/live-test-shim.js
new file mode 100644
index 0000000000..45ab9ba48b
--- /dev/null
+++ b/browser/extensions/webcompat/shims/live-test-shim.js
@@ -0,0 +1,82 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+if (!window.LiveTestShimPromise) {
+  const originalUrl = document.currentScript.src;
+
+  const shimId = "LiveTestShim";
+
+  const sendMessageToAddon = (function () {
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function (message) {
+      const messageId =
+        Math.random().toString(36).substring(2) + Date.now().toString(36);
+      return new Promise(resolve => {
+        const payload = {
+          message,
+          messageId,
+          shimId,
+        };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  async function go(options) {
+    try {
+      const o = document.getElementById("shims");
+      const cl = o.classList;
+      cl.remove("red");
+      cl.add("green");
+      o.innerText = JSON.stringify(options || "");
+    } catch (_) {}
+
+    if (window !== top) {
+      return;
+    }
+
+    await sendMessageToAddon("optIn");
+
+    const s = document.createElement("script");
+    s.src = originalUrl;
+    document.head.appendChild(s);
+  }
+
+  window[`${shimId}Promise`] = sendMessageToAddon("getOptions").then(
+    options => {
+      if (document.readyState !== "loading") {
+        go(options);
+      } else {
+        window.addEventListener("DOMContentLoaded", () => {
+          go(options);
+        });
+      }
+    }
+  );
+}
diff --git a/browser/extensions/webcompat/shims/maxmind-geoip.js b/browser/extensions/webcompat/shims/maxmind-geoip.js
new file mode 100644
index 0000000000..e5eb1e45a3
--- /dev/null
+++ b/browser/extensions/webcompat/shims/maxmind-geoip.js
@@ -0,0 +1,69 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1754389 - Shim Maxmind GeoIP library
+ *
+ * Some sites rely on Maxmind's GeoIP library which gets blocked by ETP's
+ * fingerprinter blocking. With the library window global not being defined
+ * functionality may break or the site does not render at all. This shim
+ * has it return the United States as the location for all users.
+ */
+
+if (!window.geoip2) {
+  const continent = {
+    code: "NA",
+    geoname_id: 6255149,
+    names: {
+      de: "Nordamerika",
+      en: "North America",
+      es: "Norteamérica",
+      fr: "Amérique du Nord",
+      ja: "北アメリカ",
+      "pt-BR": "América do Norte",
+      ru: "Северная Америка",
+      "zh-CN": "北美洲",
+    },
+  };
+
+  const country = {
+    geoname_id: 6252001,
+    iso_code: "US",
+    names: {
+      de: "USA",
+      en: "United States",
+      es: "Estados Unidos",
+      fr: "États-Unis",
+      ja: "アメリカ合衆国",
+      "pt-BR": "Estados Unidos",
+      ru: "США",
+      "zh-CN": "美国",
+    },
+  };
+
+  const city = {
+    names: {
+      en: "",
+    },
+  };
+
+  const callback = onSuccess => {
+    requestAnimationFrame(() => {
+      onSuccess({
+        city,
+        continent,
+        country,
+        registered_country: country,
+      });
+    });
+  };
+
+  window.geoip2 = {
+    country: callback,
+    city: callback,
+    insights: callback,
+  };
+}
diff --git a/browser/extensions/webcompat/shims/microsoftLogin.js b/browser/extensions/webcompat/shims/microsoftLogin.js
new file mode 100644
index 0000000000..ebbfb2fbff
--- /dev/null
+++ b/browser/extensions/webcompat/shims/microsoftLogin.js
@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const SANDBOX_ATTR = "allow-storage-access-by-user-activation";
+
+console.warn(
+  "Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1638383 for details."
+);
+
+// Watches for MS auth iframes and adds missing sandbox attribute. The attribute
+// is required so the third-party iframe can gain access to its first party
+// storage via the Storage Access API.
+function init() {
+  const observer = new MutationObserver(() => {
+    document.body
+      .querySelectorAll("iframe[id^='msalRenewFrame'][sandbox]")
+      .forEach(frame => {
+        frame.sandbox.add(SANDBOX_ATTR);
+      });
+  });
+
+  observer.observe(document.body, {
+    attributes: true,
+    subtree: false,
+    childList: true,
+  });
+}
+window.addEventListener("DOMContentLoaded", init);
diff --git a/browser/extensions/webcompat/shims/microsoftVirtualAssistant.js b/browser/extensions/webcompat/shims/microsoftVirtualAssistant.js
new file mode 100644
index 0000000000..4b4493750c
--- /dev/null
+++ b/browser/extensions/webcompat/shims/microsoftVirtualAssistant.js
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1801277 - Shim Microsoft virtual assistant.
+ *
+ * The microsoft virtual assistant will break when accessing the indexedDB that
+ * will throw a security error because the virtual assistant is under a
+ * third-party tracking domain 'liveperson.net'. The shim replaces the indexedDB
+ * with a fake interface that won't throw an error.
+ */
+
+/* globals cloneInto */
+
+(function () {
+  const win = window.wrappedJSObject;
+
+  try {
+    // We only replace the indexedDB when liveperson.net is loaded in a
+    // third-party context. Note that this is not strictly correct because
+    // this is a cross-origin check but not a third-party check.
+    if (win.parent == win || win.location.origin == win.top.location.origin) {
+      return;
+    }
+  } catch (e) {
+    // If we get a security error when accessing the top-level origin, this
+    // shows that the window is in a cross-origin context. In this case, we can
+    // proceed to apply the shim.
+    if (e.name != "SecurityError") {
+      throw e;
+    }
+  }
+
+  const emptyMsg = cloneInto({ message: "" }, window);
+
+  const idb = {
+    open: () => win.Promise.reject(emptyMsg),
+  };
+
+  Object.defineProperty(win, "indexedDB", {
+    value: cloneInto(idb, window, { cloneFunctions: true }),
+  });
+})();
diff --git a/browser/extensions/webcompat/shims/moat.js b/browser/extensions/webcompat/shims/moat.js
new file mode 100644
index 0000000000..9957492684
--- /dev/null
+++ b/browser/extensions/webcompat/shims/moat.js
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713704 - Shim Moat ad tracker
+ *
+ * Sites such as Forbes may gate content behind Moat ads, resulting in
+ * breakage like black boxes where videos should be placed. This shim
+ * helps mitigate that breakage by allowing the placement to succeed.
+ */
+
+if (!window.moatPrebidAPI?.__A) {
+  const targeting = new Map();
+
+  const slotConfig = {
+    m_categories: ["moat_safe"],
+    m_data: "0",
+    m_safety: "safe",
+  };
+
+  window.moatPrebidApi = {
+    __A() {},
+    disableLogging() {},
+    enableLogging() {},
+    getMoatTargetingForPage: () => slotConfig,
+    getMoatTargetingForSlot(slot) {
+      return targeting.get(slot?.getSlotElementId());
+    },
+    pageDataAvailable: () => true,
+    safetyDataAvailable: () => true,
+    setMoatTargetingForAllSlots() {
+      for (const slot of window.googletag.pubads().getSlots() || []) {
+        targeting.set(slot.getSlotElementId(), slot.getTargeting());
+      }
+    },
+    setMoatTargetingForSlot(slot) {
+      targeting.set(slot?.getSlotElementId(), slotConfig);
+    },
+    slotDataAvailable() {
+      return window.googletag?.pubads().getSlots().length > 0;
+    },
+  };
+}
diff --git a/browser/extensions/webcompat/shims/mochitest-shim-1.js b/browser/extensions/webcompat/shims/mochitest-shim-1.js
new file mode 100644
index 0000000000..d95059cf7a
--- /dev/null
+++ b/browser/extensions/webcompat/shims/mochitest-shim-1.js
@@ -0,0 +1,87 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+if (!window.MochitestShimPromise) {
+  const originalUrl = document.currentScript.src;
+
+  const shimId = "MochitestShim";
+
+  const sendMessageToAddon = (function () {
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function (message) {
+      const messageId =
+        Math.random().toString(36).substring(2) + Date.now().toString(36);
+      return new Promise(resolve => {
+        const payload = {
+          message,
+          messageId,
+          shimId,
+        };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  async function go(options) {
+    try {
+      const o = document.getElementById("shims");
+      const cl = o.classList;
+      cl.remove("red");
+      cl.add("green");
+      o.innerText = JSON.stringify(options || "");
+    } catch (_) {}
+
+    window.shimPromiseResolve("shimmed");
+
+    if (window !== top) {
+      window.optInPromiseResolve(false);
+      return;
+    }
+
+    await sendMessageToAddon("optIn");
+
+    window.doingOptIn = true;
+    const s = document.createElement("script");
+    s.src = originalUrl;
+    s.onerror = () => window.optInPromiseResolve("error");
+    document.head.appendChild(s);
+  }
+
+  window[`${shimId}Promise`] = new Promise(resolve => {
+    sendMessageToAddon("getOptions").then(options => {
+      if (document.readyState !== "loading") {
+        resolve(go(options));
+      } else {
+        window.addEventListener("DOMContentLoaded", () => {
+          resolve(go(options));
+        });
+      }
+    });
+  });
+}
diff --git a/browser/extensions/webcompat/shims/mochitest-shim-2.js b/browser/extensions/webcompat/shims/mochitest-shim-2.js
new file mode 100644
index 0000000000..bc5536405e
--- /dev/null
+++ b/browser/extensions/webcompat/shims/mochitest-shim-2.js
@@ -0,0 +1,85 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals browser */
+
+if (!window.testPromise) {
+  const originalUrl = document.currentScript.src;
+
+  const shimId = "MochitestShim2";
+
+  const sendMessageToAddon = (function () {
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function (message) {
+      const messageId =
+        Math.random().toString(36).substring(2) + Date.now().toString(36);
+      return new Promise(resolve => {
+        const payload = {
+          message,
+          messageId,
+          shimId,
+        };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  async function go(options) {
+    try {
+      const o = document.getElementById("shims");
+      const cl = o.classList;
+      cl.remove("red");
+      cl.add("green");
+      o.innerText = JSON.stringify(options || "");
+    } catch (_) {}
+
+    window.shimPromiseResolve("shimmed");
+
+    if (window !== top) {
+      window.optInPromiseResolve(false);
+      return;
+    }
+
+    await sendMessageToAddon("optIn");
+
+    window.doingOptIn = true;
+    const s = document.createElement("script");
+    s.src = originalUrl;
+    s.onerror = () => window.optInPromiseResolve("error");
+    document.head.appendChild(s);
+  }
+
+  sendMessageToAddon("getOptions").then(options => {
+    if (document.readyState !== "loading") {
+      go(options);
+    } else {
+      window.addEventListener("DOMContentLoaded", () => {
+        go(options);
+      });
+    }
+  });
+}
diff --git a/browser/extensions/webcompat/shims/mochitest-shim-3.js b/browser/extensions/webcompat/shims/mochitest-shim-3.js
new file mode 100644
index 0000000000..dc0a8005f5
--- /dev/null
+++ b/browser/extensions/webcompat/shims/mochitest-shim-3.js
@@ -0,0 +1,7 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+window.shimPromiseResolve("shimmed");
diff --git a/browser/extensions/webcompat/shims/nielsen.js b/browser/extensions/webcompat/shims/nielsen.js
new file mode 100644
index 0000000000..d34528a7c1
--- /dev/null
+++ b/browser/extensions/webcompat/shims/nielsen.js
@@ -0,0 +1,111 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1760754 - Shim Nielsen tracker
+ *
+ * Sites expecting the Nielsen tracker to load properly can break if it
+ * is blocked. This shim mitigates that breakage by loading a stand-in.
+ */
+
+if (!window.nol_t) {
+  const cid = "";
+
+  let domain = "";
+  let schemeHost = "";
+  let scriptName = "";
+  try {
+    const url = document?.currentScript?.src;
+    const { pathname, protocol, host } = new URL(url);
+    domain = host.split(".").slice(0, -2).join(".");
+    schemeHost = `${protocol}//${host}/`;
+    scriptName = pathname.split("/").pop();
+  } catch (_) {}
+
+  const NolTracker = class {
+    CONST = {
+      max_tags: 20,
+    };
+    feat = {};
+    globals = {
+      cid,
+      content: "0",
+      defaultApidFile: "config250",
+      defaultErrorParams: {
+        nol_vcid: "c00",
+        nol_clientid: "",
+      },
+      domain,
+      fpidSfCodeList: [""],
+      init() {},
+      tagCurrRetry: -1,
+      tagMaxRetry: 3,
+      wlCurrRetry: -1,
+      wlMaxRetry: 3,
+    };
+    pmap = [];
+    pvar = {
+      cid,
+      content: "0",
+      cookies_enabled: "n",
+      server: domain,
+    };
+    scriptName = [scriptName];
+    version = "6.0.107";
+
+    addScript() {}
+    catchLinkOverlay() {}
+    clickEvent() {}
+    clickTrack() {}
+    do_sample() {}
+    downloadEvent() {}
+    eventTrack() {}
+    filter() {}
+    fireToUrl() {}
+    getSchemeHost() {
+      return schemeHost;
+    }
+    getVersion() {}
+    iframe() {}
+    in_sample() {
+      return true;
+    }
+    injectBsdk() {}
+    invite() {}
+    linkTrack() {}
+    mergeFeatures() {}
+    pageEvent() {}
+    pause() {}
+    populateWhitelist() {}
+    post() {}
+    postClickTrack() {}
+    postData() {}
+    postEvent() {}
+    postEventTrack() {}
+    postLinkTrack() {}
+    prefix() {
+      return "";
+    }
+    processDdrsSvc() {}
+    random() {}
+    record() {
+      return this;
+    }
+    regLinkOverlay() {}
+    regListen() {}
+    retrieveCiFileViaCors() {}
+    sectionEvent() {}
+    sendALink() {}
+    sendForm() {}
+    sendIt() {}
+    slideEvent() {}
+    whitelistAssigned() {}
+  };
+
+  window.nol_t = () => {
+    return new NolTracker();
+  };
+}
diff --git a/browser/extensions/webcompat/shims/optimizely.js b/browser/extensions/webcompat/shims/optimizely.js
new file mode 100644
index 0000000000..dcda87421d
--- /dev/null
+++ b/browser/extensions/webcompat/shims/optimizely.js
@@ -0,0 +1,205 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Bug 1714431 - Shim Optimizely
+ *
+ * This shim stubs out window.optimizely for those sites which
+ * break when it is not successfully loaded.
+ */
+
+if (!window.optimizely?.state) {
+  const behavior = {
+    query: () => [],
+  };
+
+  const dcp = {
+    getAttributeValue() {},
+    waitForAttributeValue: () => Promise.resolve(),
+  };
+
+  const data = {
+    accountId: "",
+    audiences: {},
+    campaigns: {},
+    clientName: "js",
+    clientVersion: "0.166.0",
+    dcpServiceId: null,
+    events: {},
+    experiments: {},
+    groups: {},
+    pages: {},
+    projectId: "",
+    revision: "",
+    snippetId: null,
+    variations: {},
+  };
+
+  const activationId = String(Date.now());
+
+  const state = {
+    getActivationId() {
+      return activationId;
+    },
+    getActiveExperimentIds() {
+      return [];
+    },
+    getCampaignStateLists() {
+      return {};
+    },
+    getCampaignStates() {
+      return {};
+    },
+    getDecisionObject() {
+      return null;
+    },
+    getDecisionString() {
+      return null;
+    },
+    getExperimentStates() {
+      return {};
+    },
+    getPageStates() {
+      return {};
+    },
+    getRedirectInfo() {
+      return null;
+    },
+    getVariationMap() {
+      return {};
+    },
+    isGlobalHoldback() {
+      return false;
+    },
+  };
+
+  const poll = (fn, to) => {
+    setInterval(() => {
+      try {
+        fn();
+      } catch (_) {}
+    }, to);
+  };
+
+  const waitUntil = test => {
+    let interval, resolve;
+    function check() {
+      try {
+        if (test()) {
+          clearInterval(interval);
+          resolve?.();
+          return true;
+        }
+      } catch (_) {}
+      return false;
+    }
+    return new Promise(r => {
+      resolve = r;
+      if (check()) {
+        resolve();
+        return;
+      }
+      interval = setInterval(check, 250);
+    });
+  };
+
+  const waitForElement = sel => {
+    return waitUntil(() => {
+      document.querySelector(sel);
+    });
+  };
+
+  const observeSelector = (sel, fn, opts) => {
+    let interval;
+    const observed = new Set();
+    function check() {
+      try {
+        for (const e of document.querySelectorAll(sel)) {
+          if (observed.has(e)) {
+            continue;
+          }
+          observed.add(e);
+          try {
+            fn(e);
+          } catch (_) {}
+          if (opts.once) {
+            clearInterval(interval);
+          }
+        }
+      } catch (_) {}
+    }
+    interval = setInterval(check, 250);
+    const timeout = { opts };
+    if (timeout) {
+      setTimeout(() => {
+        clearInterval(interval);
+      }, timeout);
+    }
+  };
+
+  const utils = {
+    Promise: window.Promise,
+    observeSelector,
+    poll,
+    waitForElement,
+    waitUntil,
+  };
+
+  const visitorId = {
+    randomId: "",
+  };
+
+  let browserVersion = "";
+  try {
+    browserVersion = navigator.userAgent.match(/rv:(.*)\)/)[1];
+  } catch (_) {}
+
+  const visitor = {
+    browserId: "ff",
+    browserVersion,
+    currentTimestamp: Date.now(),
+    custom: {},
+    customBehavior: {},
+    device: "desktop",
+    device_type: "desktop_laptop",
+    events: [],
+    first_session: true,
+    offset: 240,
+    referrer: null,
+    source_type: "direct",
+    visitorId,
+  };
+
+  window.optimizely = {
+    data: {
+      note: "Obsolete, use optimizely.get('data') instead",
+    },
+    get(e) {
+      switch (e) {
+        case "behavior":
+          return behavior;
+        case "data":
+          return data;
+        case "dcp":
+          return dcp;
+        case "jquery":
+          throw new Error("jQuery not implemented");
+        case "session":
+          return undefined;
+        case "state":
+          return state;
+        case "utils":
+          return utils;
+        case "visitor":
+          return visitor;
+        case "visitor_id":
+          return visitorId;
+      }
+      return undefined;
+    },
+    initialized: true,
+    push() {},
+    state: {},
+  };
+}
diff --git a/browser/extensions/webcompat/shims/play.svg b/browser/extensions/webcompat/shims/play.svg
new file mode 100644
index 0000000000..df5bbcb4f1
--- /dev/null
+++ b/browser/extensions/webcompat/shims/play.svg
@@ -0,0 +1,7 @@
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/.
+  source: https://searchfox.org/mozilla-central/source/devtools/client/themes/images/play.svg -->
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
+  <path fill="#fff" d="M20.436 11.37L5.904 2.116c-.23-.147-.523-.158-.762-.024-.24.132-.39.384-.39.657v18.5c0 .273.15.525.39.657.112.063.236.093.36.093.14 0 .28-.04.402-.117l14.53-9.248c.218-.138.35-.376.35-.633 0-.256-.132-.495-.348-.633z"/>
+</svg>
diff --git a/browser/extensions/webcompat/shims/private-browsing-web-api-fixes.js b/browser/extensions/webcompat/shims/private-browsing-web-api-fixes.js
new file mode 100644
index 0000000000..bc45aeda26
--- /dev/null
+++ b/browser/extensions/webcompat/shims/private-browsing-web-api-fixes.js
@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1714354 - Fix for site issues with web APIs in private browsing
+ *
+ * Some sites expect specific DOM APIs to work in specific ways, which
+ * is not always true, such as in private browsing mode. We work around
+ * related breakage by undefining those APIs entirely in private
+ * browsing mode for those sites.
+ */
+
+delete window.wrappedJSObject.caches;
+delete window.wrappedJSObject.indexedDB;
diff --git a/browser/extensions/webcompat/shims/rambler-authenticator.js b/browser/extensions/webcompat/shims/rambler-authenticator.js
new file mode 100644
index 0000000000..1fe074b660
--- /dev/null
+++ b/browser/extensions/webcompat/shims/rambler-authenticator.js
@@ -0,0 +1,84 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+if (!window.ramblerIdHelper) {
+  const originalScript = document.currentScript.src;
+
+  const sendMessageToAddon = (function () {
+    const shimId = "Rambler";
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function (message) {
+      const messageId =
+        Math.random().toString(36).substring(2) + Date.now().toString(36);
+      return new Promise(resolve => {
+        const payload = {
+          message,
+          messageId,
+          shimId,
+        };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  const ramblerIdHelper = {
+    getProfileInfo: (successCallback, errorCallback) => {
+      successCallback({});
+    },
+    openAuth: () => {
+      sendMessageToAddon("optIn").then(function () {
+        const openAuthArgs = arguments;
+        window.ramblerIdHelper = undefined;
+        const s = document.createElement("script");
+        s.src = originalScript;
+        document.head.appendChild(s);
+        s.addEventListener("load", () => {
+          const helper = window.ramblerIdHelper;
+          for (const { fn, args } of callLog) {
+            helper[fn].apply(helper, args);
+          }
+          helper.openAuth.apply(helper, openAuthArgs);
+        });
+      });
+    },
+  };
+
+  const callLog = [];
+  function addLoggedCall(fn) {
+    ramblerIdHelper[fn] = () => {
+      callLog.push({ fn, args: arguments });
+    };
+  }
+
+  addLoggedCall("registerOnFrameCloseCallback");
+  addLoggedCall("registerOnFrameRedirect");
+  addLoggedCall("registerOnPossibleLoginCallback");
+  addLoggedCall("registerOnPossibleLogoutCallback");
+  addLoggedCall("registerOnPossibleOauthLoginCallback");
+
+  window.ramblerIdHelper = ramblerIdHelper;
+}
diff --git a/browser/extensions/webcompat/shims/rich-relevance.js b/browser/extensions/webcompat/shims/rich-relevance.js
new file mode 100644
index 0000000000..aea85c030a
--- /dev/null
+++ b/browser/extensions/webcompat/shims/rich-relevance.js
@@ -0,0 +1,288 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713725 - Shim Rich Relevance personalized shopping
+ *
+ * Sites may expect the Rich Relevance personalized shopping API to load,
+ * breaking if it is blocked. This shim attempts to limit breakage on those
+ * site to just the personalized shopping aspects, by stubbing out the APIs.
+ */
+
+if (!window.r3_common) {
+  const jsonCallback = window.RR?.jsonCallback;
+  const defaultCallback = window.RR?.defaultCallback;
+
+  const getRandomString = (l = 66) => {
+    const v = crypto.getRandomValues(new Uint8Array(l));
+    const s = Array.from(v, c => c.toString(16)).join("");
+    return s.slice(0, l);
+  };
+
+  const call = (fn, ...args) => {
+    if (typeof fn === "function") {
+      try {
+        fn(...args);
+      } catch (e) {
+        console.error(e);
+      }
+    }
+  };
+
+  class r3_generic {
+    type = "GENERIC";
+    createScript() {}
+    destroy() {}
+  }
+
+  class r3_addtocart extends r3_generic {
+    type = "ADDTOCART";
+    addItemIdToCart() {}
+  }
+
+  class r3_addtoregistry extends r3_generic {
+    type = "ADDTOREGISTRY";
+    addItemIdCentsQuantity() {}
+  }
+
+  class r3_brand extends r3_generic {
+    type = "BRAND";
+  }
+
+  class r3_cart extends r3_generic {
+    type = "CART";
+    addItemId() {}
+    addItemIdCentsQuantity() {}
+    addItemIdDollarsAndCentsQuantity() {}
+    addItemIdPriceQuantity() {}
+  }
+
+  class r3_category extends r3_generic {
+    type = "CATEGORY";
+    addItemId() {}
+    setId() {}
+    setName() {}
+    setParentId() {}
+    setTopName() {}
+  }
+
+  class r3_common extends r3_generic {
+    type = "COMMON";
+    baseUrl = "https://recs.richrelevance.com/rrserver/";
+    devFlags = {};
+    jsFileName = "p13n_generated.js";
+    RICHSORT = {
+      paginate() {},
+      filterPrice() {},
+      filterAttribute() {},
+    };
+    addCategoryHintId() {}
+    addClickthruParams() {}
+    addContext() {}
+    addFilter() {}
+    addFilterBrand() {}
+    addFilterCategory() {}
+    addItemId() {}
+    addItemIdToCart() {}
+    addPlacementType() {}
+    addRefinement() {}
+    addSearchTerm() {}
+    addSegment() {}
+    blockItemId() {}
+    enableCfrad() {}
+    enableRad() {}
+    forceDebugMode() {}
+    forceDevMode() {}
+    forceDisplayMode() {}
+    forceLocale() {}
+    initFromParams() {}
+    setApiKey() {}
+    setBaseUrl() {}
+    setCartValue() {}
+    setChannel() {}
+    setClickthruServer() {}
+    setCurrency() {}
+    setDeviceId() {}
+    setFilterBrandsIncludeMatchingElements() {}
+    setForcedTreatment() {}
+    setImageServer() {}
+    setLanguage() {}
+    setMVTForcedTreatment() {}
+    setNoCookieMode() {}
+    setPageBrand() {}
+    setPrivateMode() {}
+    setRefinementFallback() {}
+    setRegionId() {}
+    setRegistryId() {}
+    setRegistryType() {}
+    setSessionId() {}
+    setUserId() {}
+    useDummyData() {}
+  }
+
+  class r3_error extends r3_generic {
+    type = "ERROR";
+  }
+
+  class r3_home extends r3_generic {
+    type = "HOME";
+  }
+
+  class r3_item extends r3_generic {
+    type = "ITEM";
+    addAttribute() {}
+    addCategory() {}
+    addCategoryId() {}
+    setBrand() {}
+    setEndDate() {}
+    setId() {}
+    setImageId() {}
+    setLinkId() {}
+    setName() {}
+    setPrice() {}
+    setRating() {}
+    setRecommendable() {}
+    setReleaseDate() {}
+    setSalePrice() {}
+  }
+
+  class r3_personal extends r3_generic {
+    type = "PERSONAL";
+  }
+
+  class r3_purchased extends r3_generic {
+    type = "PURCHASED";
+    addItemId() {}
+    addItemIdCentsQuantity() {}
+    addItemIdDollarsAndCentsQuantity() {}
+    addItemIdPriceQuantity() {}
+    setOrderNumber() {}
+    setPromotionCode() {}
+    setShippingCost() {}
+    setTaxes() {}
+    setTotalPrice() {}
+  }
+
+  class r3_search extends r3_generic {
+    type = "SEARCH";
+    addItemId() {}
+    setTerms() {}
+  }
+
+  class r3_wishlist extends r3_generic {
+    type = "WISHLIST";
+    addItemId() {}
+  }
+
+  const RR = {
+    add() {},
+    addItemId() {},
+    addItemIdCentsQuantity() {},
+    addItemIdDollarsAndCentsQuantity() {},
+    addItemIdPriceQuantity() {},
+    addItemIdToCart() {},
+    addObject() {},
+    addSearchTerm() {},
+    c() {},
+    charset: "UTF-8",
+    checkParamCookieValue: () => null,
+    d: document,
+    data: {
+      JSON: {
+        placements: [],
+      },
+    },
+    debugWindow() {},
+    set defaultCallback(fn) {
+      call(fn);
+    },
+    fixName: n => n,
+    genericAddItemPriceQuantity() {},
+    get() {},
+    getDomElement(a) {
+      return typeof a === "string" && a ? document.querySelector(a) : null;
+    },
+    id() {},
+    insert() {},
+    insertDynamicPlacement() {},
+    isArray: a => Array.isArray(a),
+    js() {},
+    set jsonCallback(fn) {
+      call(fn, {});
+    },
+    l: document.location.href,
+    lc() {},
+    noCookieMode: false,
+    ol() {},
+    onloadCalled: true,
+    pq() {},
+    rcsCookieDefaultDuration: 364,
+    registerPageType() {},
+    registeredPageTypes: {
+      ADDTOCART: r3_addtocart,
+      ADDTOREGISTRY: r3_addtoregistry,
+      BRAND: r3_brand,
+      CART: r3_cart,
+      CATEGORY: r3_category,
+      COMMON: r3_common,
+      ERROR: r3_error,
+      GENERIC: r3_generic,
+      HOME: r3_home,
+      ITEM: r3_item,
+      PERSONAL: r3_personal,
+      PURCHASED: r3_purchased,
+      SEARCH: r3_search,
+      WISHLIST: r3_wishlist,
+    },
+    renderDynamicPlacements() {},
+    set() {},
+    setCharset() {},
+    U: "undefined",
+    unregisterAllPageType() {},
+    unregisterPageType() {},
+  };
+
+  Object.assign(window, {
+    r3() {},
+    r3_addtocart,
+    r3_addtoregistry,
+    r3_brand,
+    r3_cart,
+    r3_category,
+    r3_common,
+    r3_error,
+    r3_generic,
+    r3_home,
+    r3_item,
+    r3_personal,
+    r3_placement() {},
+    r3_purchased,
+    r3_search,
+    r3_wishlist,
+    RR,
+    rr_addLoadEvent() {},
+    rr_annotations_array: [undefined],
+    rr_call_after_flush() {},
+    rr_create_script() {},
+    rr_dynamic: {
+      placements: [],
+    },
+    rr_flush() {},
+    rr_flush_onload() {},
+    rr_insert_placement() {},
+    rr_onload_called: true,
+    rr_placement_place_holders: [],
+    rr_placements: [],
+    rr_recs: {
+      placements: [],
+    },
+    rr_remote_data: getRandomString(),
+    rr_v: "1.2.6.20210212",
+  });
+
+  call(jsonCallback);
+  call(defaultCallback, {});
+}
diff --git a/browser/extensions/webcompat/shims/spotify-embed.js b/browser/extensions/webcompat/shims/spotify-embed.js
new file mode 100644
index 0000000000..62ad05b725
--- /dev/null
+++ b/browser/extensions/webcompat/shims/spotify-embed.js
@@ -0,0 +1,133 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* globals exportFunction */
+
+"use strict";
+
+/**
+ * Spotify embeds default to "track preview mode". They require first-party
+ * storage access in order to detect the login status and allow the user to play
+ * the whole song or add it to their library.
+ * Upon clicking the "play" button in the preview view this shim attempts to get
+ * storage access and on success, reloads the frame and plays the full track.
+ * This only works if the user is already logged in to Spotify in the
+ * first-party context.
+ */
+
+const AUTOPLAY_FLAG = "shimPlayAfterStorageAccess";
+const SELECTOR_PREVIEW_PLAY = 'div[data-testid="preview-play-pause"] > button';
+const SELECTOR_FULL_PLAY = 'button[data-testid="play-pause-button"]';
+
+/**
+ * Promise-wrapper around DOMContentLoaded event.
+ */
+function waitForDOMContentLoaded() {
+  return new Promise(resolve => {
+    window.addEventListener("DOMContentLoaded", resolve, { once: true });
+  });
+}
+
+/**
+ * Listener for the preview playback button which requests storage access and
+ * reloads the page.
+ */
+function previewPlayButtonListener(event) {
+  const { target, isTrusted } = event;
+  if (!isTrusted) {
+    return;
+  }
+
+  const button = target.closest("button");
+  if (!button) {
+    return;
+  }
+
+  // Filter for the preview playback button. This won't match the full
+  // playback button that is shown when the user is logged in.
+  if (!button.matches(SELECTOR_PREVIEW_PLAY)) {
+    return;
+  }
+
+  // The storage access request below runs async so playback won't start
+  // immediately. Mitigate this UX issue by updating the clicked element's
+  // style so the user gets some immediate feedback.
+  button.style.opacity = 0.5;
+  event.stopPropagation();
+  event.preventDefault();
+
+  console.debug("Requesting storage access.", location.origin);
+  document
+    .requestStorageAccess()
+    // When storage access is granted, reload the frame for the embedded
+    // player to detect the login state and give us full playback
+    // capabilities.
+    .then(() => {
+      // Use a flag to indicate that we want to click play after reload.
+      // This is so the user does not have to click play twice.
+      sessionStorage.setItem(AUTOPLAY_FLAG, "true");
+      console.debug("Reloading after storage access grant.");
+      location.reload();
+    })
+    // If the user denies the storage access prompt we can't use the login
+    // state. Attempt start preview playback instead.
+    .catch(() => {
+      button.click();
+    })
+    // Reset button style for both success and error case.
+    .finally(() => {
+      button.style.opacity = 1.0;
+    });
+}
+
+/**
+ * Attempt to start (full) playback. Waits for the play button to appear and
+ * become ready.
+ */
+async function startFullPlayback() {
+  // Wait for DOMContentLoaded before looking for the playback button.
+  await waitForDOMContentLoaded();
+
+  let numTries = 0;
+  let intervalId = setInterval(() => {
+    try {
+      document.querySelector(SELECTOR_FULL_PLAY).click();
+      clearInterval(intervalId);
+      console.debug("Clicked play after storage access grant.");
+    } catch (e) {}
+    numTries++;
+
+    if (numTries >= 50) {
+      console.debug("Can not start playback. Giving up.");
+      clearInterval(intervalId);
+    }
+  }, 200);
+}
+
+(async () => {
+  // Only run the shim for embedded iframes.
+  if (window.top == window) {
+    return;
+  }
+
+  console.warn(
+    `When using the Spotify embedded player, Firefox calls the Storage Access API on behalf of the site. See https://bugzilla.mozilla.org/show_bug.cgi?id=1792395 for details.`
+  );
+
+  // Already requested storage access before the reload, trigger playback.
+  if (sessionStorage.getItem(AUTOPLAY_FLAG) == "true") {
+    sessionStorage.removeItem(AUTOPLAY_FLAG);
+
+    await startFullPlayback();
+    return;
+  }
+
+  // Wait for the user to click the preview play button. If the player has
+  // already loaded the full version, this method will do nothing.
+  document.documentElement.addEventListener(
+    "click",
+    previewPlayButtonListener,
+    { capture: true }
+  );
+})();
diff --git a/browser/extensions/webcompat/shims/tracking-pixel.png b/browser/extensions/webcompat/shims/tracking-pixel.png
new file mode 100644
index 0000000000..52c591798e
--- /dev/null
+++ b/browser/extensions/webcompat/shims/tracking-pixel.png
diff --git a/browser/extensions/webcompat/shims/vast2.xml b/browser/extensions/webcompat/shims/vast2.xml
new file mode 100644
index 0000000000..3536ccfc0f
--- /dev/null
+++ b/browser/extensions/webcompat/shims/vast2.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  Bug 1713693 - Shim Doubleclick
+
+  Some sites rely on an XML VAST Ad response from Doubleclick, or will
+  break (showing black boxes instead of videos, etc). This shim mitigates
+  such breakage.
+-->
+<VAST version="2.0"></VAST>
diff --git a/browser/extensions/webcompat/shims/vast3.xml b/browser/extensions/webcompat/shims/vast3.xml
new file mode 100644
index 0000000000..ae03f0dc14
--- /dev/null
+++ b/browser/extensions/webcompat/shims/vast3.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  Bug 1713693 - Shim Doubleclick
+
+  Some sites rely on an XML VAST Ad response from Doubleclick, or will
+  break (showing black boxes instead of videos, etc). This shim mitigates
+  such breakage.
+-->
+<VAST version="3.0"></VAST>
diff --git a/browser/extensions/webcompat/shims/vidible.js b/browser/extensions/webcompat/shims/vidible.js
new file mode 100644
index 0000000000..1d45bc0f7e
--- /dev/null
+++ b/browser/extensions/webcompat/shims/vidible.js
@@ -0,0 +1,424 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1713710 - Shim Vidible video player
+ *
+ * Sites relying on Vidible's video player may experience broken videos if that
+ * script is blocked. This shim allows users to opt into viewing those videos
+ * regardless of any tracking consequences, by providing placeholders for each.
+ */
+
+if (!window.vidible?.version) {
+  const PlayIconURL = "https://smartblock.firefox.etp/play.svg";
+
+  const originalScript = document.currentScript.src;
+
+  const getGUID = () => {
+    const v = crypto.getRandomValues(new Uint8Array(20));
+    return Array.from(v, c => c.toString(16)).join("");
+  };
+
+  const sendMessageToAddon = (function () {
+    const shimId = "Vidible";
+    const pendingMessages = new Map();
+    const channel = new MessageChannel();
+    channel.port1.onerror = console.error;
+    channel.port1.onmessage = event => {
+      const { messageId, response } = event.data;
+      const resolve = pendingMessages.get(messageId);
+      if (resolve) {
+        pendingMessages.delete(messageId);
+        resolve(response);
+      }
+    };
+    function reconnect() {
+      const detail = {
+        pendingMessages: [...pendingMessages.values()],
+        port: channel.port2,
+        shimId,
+      };
+      window.dispatchEvent(new CustomEvent("ShimConnects", { detail }));
+    }
+    window.addEventListener("ShimHelperReady", reconnect);
+    reconnect();
+    return function (message) {
+      const messageId = getGUID();
+      return new Promise(resolve => {
+        const payload = { message, messageId, shimId };
+        pendingMessages.set(messageId, resolve);
+        channel.port1.postMessage(payload);
+      });
+    };
+  })();
+
+  const Shimmer = (function () {
+    // If a page might store references to an object before we replace it,
+    // ensure that it only receives proxies to that object created by
+    // `Shimmer.proxy(obj)`. Later when the unshimmed object is created,
+    // call `Shimmer.unshim(proxy, unshimmed)`. This way the references
+    // will automatically "become" the unshimmed object when appropriate.
+
+    const shimmedObjects = new WeakMap();
+    const unshimmedObjects = new Map();
+
+    function proxy(shim) {
+      if (shimmedObjects.has(shim)) {
+        return shimmedObjects.get(shim);
+      }
+
+      const prox = new Proxy(shim, {
+        get: (target, k) => {
+          if (unshimmedObjects.has(prox)) {
+            return unshimmedObjects.get(prox)[k];
+          }
+          return target[k];
+        },
+        apply: (target, thisArg, args) => {
+          if (unshimmedObjects.has(prox)) {
+            return unshimmedObjects.get(prox)(...args);
+          }
+          return target.apply(thisArg, args);
+        },
+        construct: (target, args) => {
+          if (unshimmedObjects.has(prox)) {
+            return new unshimmedObjects.get(prox)(...args);
+          }
+          return new target(...args);
+        },
+      });
+      shimmedObjects.set(shim, prox);
+      shimmedObjects.set(prox, prox);
+
+      for (const key in shim) {
+        const value = shim[key];
+        if (typeof value === "function") {
+          shim[key] = function () {
+            const unshimmed = unshimmedObjects.get(prox);
+            if (unshimmed) {
+              return unshimmed[key].apply(unshimmed, arguments);
+            }
+            return value.apply(this, arguments);
+          };
+        } else if (typeof value !== "object" || value === null) {
+          shim[key] = value;
+        } else {
+          shim[key] = Shimmer.proxy(value);
+        }
+      }
+
+      return prox;
+    }
+
+    function unshim(shim, unshimmed) {
+      unshimmedObjects.set(shim, unshimmed);
+
+      for (const prop in shim) {
+        if (prop in unshimmed) {
+          const un = unshimmed[prop];
+          if (typeof un === "object" && un !== null) {
+            unshim(shim[prop], un);
+          }
+        } else {
+          unshimmedObjects.set(shim[prop], undefined);
+        }
+      }
+    }
+
+    return { proxy, unshim };
+  })();
+
+  const extras = [];
+  const playersByNode = new WeakMap();
+  const playerData = new Map();
+
+  const getJSONPVideoPlacements = () => {
+    return document.querySelectorAll(
+      `script[src*="delivery.vidible.tv/jsonp"]`
+    );
+  };
+
+  const allowVidible = () => {
+    if (allowVidible.promise) {
+      return allowVidible.promise;
+    }
+
+    const shim = window.vidible;
+    window.vidible = undefined;
+
+    allowVidible.promise = sendMessageToAddon("optIn")
+      .then(() => {
+        return new Promise((resolve, reject) => {
+          const script = document.createElement("script");
+          script.src = originalScript;
+          script.addEventListener("load", () => {
+            Shimmer.unshim(shim, window.vidible);
+
+            for (const args of extras) {
+              window.visible.registerExtra(...args);
+            }
+
+            for (const jsonp of getJSONPVideoPlacements()) {
+              const { src } = jsonp;
+              const jscript = document.createElement("script");
+              jscript.onload = resolve;
+              jscript.src = src;
+              jsonp.replaceWith(jscript);
+            }
+
+            for (const [playerShim, data] of playerData.entries()) {
+              const { loadCalled, on, parent, placeholder, setup } = data;
+
+              placeholder?.remove();
+
+              const player = window.vidible.player(parent);
+              Shimmer.unshim(playerShim, player);
+
+              for (const [type, fns] of on.entries()) {
+                for (const fn of fns) {
+                  try {
+                    player.on(type, fn);
+                  } catch (e) {
+                    console.error(e);
+                  }
+                }
+              }
+
+              if (setup) {
+                player.setup(setup);
+              }
+
+              if (loadCalled) {
+                player.load();
+              }
+            }
+
+            resolve();
+          });
+
+          script.addEventListener("error", () => {
+            script.remove();
+            reject();
+          });
+
+          document.head.appendChild(script);
+        });
+      })
+      .catch(() => {
+        window.vidible = shim;
+        delete allowVidible.promise;
+      });
+
+    return allowVidible.promise;
+  };
+
+  const createVideoPlaceholder = (service, callback) => {
+    const placeholder = document.createElement("div");
+    placeholder.style = `
+      position: absolute;
+      width: 100%;
+      height: 100%;
+      min-width: 160px;
+      min-height: 100px;
+      top: 0px;
+      left: 0px;
+      background: #000;
+      color: #fff;
+      text-align: center;
+      cursor: pointer;
+      display: flex;
+      align-items: center;
+      justify-content: center;
+      background-image: url(${PlayIconURL});
+      background-position: 50% 47.5%;
+      background-repeat: no-repeat;
+      background-size: 25% 25%;
+      -moz-text-size-adjust: none;
+      -moz-user-select: none;
+      color: #fff;
+      align-items: center;
+      padding-top: 200px;
+      font-size: 14pt;
+    `;
+    placeholder.textContent = `Click to allow blocked ${service} content`;
+    placeholder.addEventListener("click", evt => {
+      evt.isTrusted && callback();
+    });
+    return placeholder;
+  };
+
+  const Player = function (parent) {
+    const existing = playersByNode.get(parent);
+    if (existing) {
+      return existing;
+    }
+
+    const player = Shimmer.proxy(this);
+    playersByNode.set(parent, player);
+
+    const placeholder = createVideoPlaceholder("Vidible", allowVidible);
+    parent.parentNode.insertBefore(placeholder, parent);
+
+    playerData.set(player, {
+      on: new Map(),
+      parent,
+      placeholder,
+    });
+    return player;
+  };
+
+  const changeData = function (fn) {
+    const data = playerData.get(this);
+    if (data) {
+      fn(data);
+      playerData.set(this, data);
+    }
+  };
+
+  Player.prototype = {
+    addEventListener() {},
+    destroy() {
+      const { placeholder } = playerData.get(this);
+      placeholder?.remove();
+      playerData.delete(this);
+    },
+    dispatchEvent() {},
+    getAdsPassedTime() {},
+    getAllMacros() {},
+    getCurrentTime() {},
+    getDuration() {},
+    getHeight() {},
+    getPixelsLog() {},
+    getPlayerContainer() {},
+    getPlayerInfo() {},
+    getPlayerStatus() {},
+    getRequestsLog() {},
+    getStripUrl() {},
+    getVolume() {},
+    getWidth() {},
+    hidePlayReplayControls() {},
+    isMuted() {},
+    isPlaying() {},
+    load() {
+      changeData(data => (data.loadCalled = true));
+    },
+    mute() {},
+    on(type, fn) {
+      changeData(({ on }) => {
+        if (!on.has(type)) {
+          on.set(type, new Set());
+        }
+        on.get(type).add(fn);
+      });
+    },
+    off(type, fn) {
+      changeData(({ on }) => {
+        on.get(type)?.delete(fn);
+      });
+    },
+    overrideMacro() {},
+    pause() {},
+    play() {},
+    playVideoByIndex() {},
+    removeEventListener() {},
+    seekTo() {},
+    sendBirthDate() {},
+    sendKey() {},
+    setup(s) {
+      changeData(data => (data.setup = s));
+      return this;
+    },
+    setVideosToPlay() {},
+    setVolume() {},
+    showPlayReplayControls() {},
+    toggleFullscreen() {},
+    toggleMute() {},
+    togglePlay() {},
+    updateBid() {},
+    version() {},
+    volume() {},
+  };
+
+  const vidible = {
+    ADVERT_CLOSED: "advertClosed",
+    AD_END: "adend",
+    AD_META: "admeta",
+    AD_PAUSED: "adpaused",
+    AD_PLAY: "adplay",
+    AD_START: "adstart",
+    AD_TIMEUPDATE: "adtimeupdate",
+    AD_WAITING: "adwaiting",
+    AGE_GATE_DISPLAYED: "agegatedisplayed",
+    BID_UPDATED: "BidUpdated",
+    CAROUSEL_CLICK: "CarouselClick",
+    CONTEXT_ENDED: "contextended",
+    CONTEXT_STARTED: "contextstarted",
+    ENTER_FULLSCREEN: "playerenterfullscreen",
+    EXIT_FULLSCREEN: "playerexitfullscreen",
+    FALLBACK: "fallback",
+    FLOAT_END_ACTION: "floatended",
+    FLOAT_START_ACTION: "floatstarted",
+    HIDE_PLAY_REPLAY_BUTTON: "hideplayreplaybutton",
+    LIGHTBOX_ACTIVATED: "lightboxactivated",
+    LIGHTBOX_DEACTIVATED: "lightboxdeactivated",
+    MUTE: "Mute",
+    PLAYER_CONTROLS_STATE_CHANGE: "playercontrolsstatechaned",
+    PLAYER_DOCKED: "playerDocked",
+    PLAYER_ERROR: "playererror",
+    PLAYER_FLOATING: "playerFloating",
+    PLAYER_READY: "playerready",
+    PLAYER_RESIZE: "playerresize",
+    PLAYLIST_END: "playlistend",
+    SEEK_END: "SeekEnd",
+    SEEK_START: "SeekStart",
+    SHARE_SCREEN_CLOSED: "sharescreenclosed",
+    SHARE_SCREEN_OPENED: "sharescreenopened",
+    SHOW_PLAY_REPLAY_BUTTON: "showplayreplaybutton",
+    SUBTITLES_DISABLED: "subtitlesdisabled",
+    SUBTITLES_ENABLED: "subtitlesenabled",
+    SUBTITLES_READY: "subtitlesready",
+    UNMUTE: "Unmute",
+    VIDEO_DATA_LOADED: "videodataloaded",
+    VIDEO_END: "videoend",
+    VIDEO_META: "videometadata",
+    VIDEO_MODULE_CREATED: "videomodulecreated",
+    VIDEO_PAUSE: "videopause",
+    VIDEO_PLAY: "videoplay",
+    VIDEO_SEEKEND: "videoseekend",
+    VIDEO_SELECTED: "videoselected",
+    VIDEO_START: "videostart",
+    VIDEO_TIMEUPDATE: "videotimeupdate",
+    VIDEO_VOLUME_CHANGED: "videovolumechanged",
+    VOLUME: "Volume",
+    _getContexts: () => [],
+    "content.CLICK": "content.click",
+    "content.IMPRESSION": "content.impression",
+    "content.QUARTILE": "content.quartile",
+    "content.VIEW": "content.view",
+    createPlayer: parent => new Player(parent),
+    createPlayerAsync: parent => new Player(parent),
+    createVPAIDPlayer: parent => new Player(parent),
+    destroyAll() {},
+    extension() {},
+    getContext() {},
+    player: parent => new Player(parent),
+    playerInceptionTime() {
+      return { undefined: 1620149827713 };
+    },
+    registerExtra(a, b, c) {
+      extras.push([a, b, c]);
+    },
+    version: () => "21.1.313",
+  };
+
+  window.vidible = Shimmer.proxy(vidible);
+
+  for (const jsonp of getJSONPVideoPlacements()) {
+    const player = new Player(jsonp);
+    const { placeholder } = playerData.get(player);
+    jsonp.parentNode.insertBefore(placeholder, jsonp);
+  }
+}
diff --git a/browser/extensions/webcompat/shims/vmad.xml b/browser/extensions/webcompat/shims/vmad.xml
new file mode 100644
index 0000000000..5bb9a5a5d5
--- /dev/null
+++ b/browser/extensions/webcompat/shims/vmad.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+  Bug 1713693 - Shim Doubleclick
+
+  Some sites rely on an XML VMAD Ad response from Doubleclick, or will
+  break (showing black boxes instead of videos, etc). This shim mitigates
+  such breakage.
+-->
+<vmap:AdBreak></vmap:AdBreak>
diff --git a/browser/extensions/webcompat/shims/webtrends.js b/browser/extensions/webcompat/shims/webtrends.js
new file mode 100644
index 0000000000..c7ef0069da
--- /dev/null
+++ b/browser/extensions/webcompat/shims/webtrends.js
@@ -0,0 +1,46 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * Bug 1766414 - Shim WebTrends Core Tag and Advanced Link Tracking
+ *
+ * Sites using WebTrends Core Tag or Link Tracking can break if they are
+ * are blocked. This shim mitigates that breakage by loading an empty module.
+ */
+
+if (!window.dcsMultiTrack) {
+  window.dcsMultiTrack = o => {
+    o?.callback?.({});
+  };
+}
+
+if (!window.WebTrends) {
+  class dcs {
+    addSelector() {
+      return this;
+    }
+    addTransform() {
+      return this;
+    }
+    DCSext = {};
+    init(obj) {
+      return this;
+    }
+    track() {
+      return this;
+    }
+  }
+
+  window.Webtrends = window.WebTrends = {
+    dcs,
+    multiTrack: window.dcsMultiTrack,
+  };
+
+  window.requestAnimationFrame(() => {
+    window.webtrendsAsyncLoad?.(dcs);
+    window.webtrendsAsyncInit?.();
+  });
+}
diff --git a/browser/extensions/webcompat/tests/browser/browser.ini b/browser/extensions/webcompat/tests/browser/browser.ini
new file mode 100644
index 0000000000..f15b901240
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/browser.ini
@@ -0,0 +1,15 @@
+[DEFAULT]
+support-files =
+  head.js
+  shims_test.js
+  shims_test_2.js
+  shims_test_3.js
+  iframe_test.html
+  shims_test.html
+  shims_test_2.html
+  shims_test_3.html
+
+[browser_aboutcompat.js]
+[browser_shims.js]
+https_first_disabled = true
+skip-if = verify
diff --git a/browser/extensions/webcompat/tests/browser/browser_aboutcompat.js b/browser/extensions/webcompat/tests/browser/browser_aboutcompat.js
new file mode 100644
index 0000000000..a448269294
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/browser_aboutcompat.js
@@ -0,0 +1,27 @@
+"use strict";
+
+add_task(async function test_about_compat_loads_properly() {
+  const tab = await BrowserTestUtils.openNewForegroundTab({
+    gBrowser,
+    opening: "about:compat",
+    waitForLoad: true,
+  });
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+    await ContentTaskUtils.waitForCondition(
+      () => content.document.querySelector("#overrides tr[data-id]"),
+      "UA overrides are listed"
+    );
+    await ContentTaskUtils.waitForCondition(
+      () => content.document.querySelector("#interventions tr[data-id]"),
+      "interventions are listed"
+    );
+    await ContentTaskUtils.waitForCondition(
+      () => content.document.querySelector("#smartblock tr[data-id]"),
+      "SmartBlock shims are listed"
+    );
+    ok(true, "Interventions are listed");
+  });
+
+  await BrowserTestUtils.removeTab(tab);
+});
diff --git a/browser/extensions/webcompat/tests/browser/browser_shims.js b/browser/extensions/webcompat/tests/browser/browser_shims.js
new file mode 100644
index 0000000000..4de900a4c6
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/browser_shims.js
@@ -0,0 +1,73 @@
+"use strict";
+
+registerCleanupFunction(() => {
+  UrlClassifierTestUtils.cleanupTestTrackers();
+  Services.prefs.clearUserPref(TRACKING_PREF);
+});
+
+add_setup(async function () {
+  await UrlClassifierTestUtils.addTestTrackers();
+});
+
+add_task(async function test_shim_disabled_by_own_pref() {
+  // Test that a shim will not apply if disabled in about:config
+
+  Services.prefs.setBoolPref(DISABLE_SHIM1_PREF, true);
+  Services.prefs.setBoolPref(TRACKING_PREF, true);
+
+  await testShimDoesNotRun();
+
+  Services.prefs.clearUserPref(DISABLE_SHIM1_PREF);
+  Services.prefs.clearUserPref(TRACKING_PREF);
+});
+
+add_task(async function test_shim_disabled_by_global_pref() {
+  // Test that a shim will not apply if disabled in about:config
+
+  Services.prefs.setBoolPref(GLOBAL_PREF, false);
+  Services.prefs.setBoolPref(DISABLE_SHIM1_PREF, false);
+  Services.prefs.setBoolPref(TRACKING_PREF, true);
+
+  await testShimDoesNotRun();
+
+  Services.prefs.clearUserPref(GLOBAL_PREF);
+  Services.prefs.clearUserPref(DISABLE_SHIM1_PREF);
+  Services.prefs.clearUserPref(TRACKING_PREF);
+});
+
+add_task(async function test_shim_disabled_hosts_notHosts() {
+  Services.prefs.setBoolPref(TRACKING_PREF, true);
+
+  await testShimDoesNotRun(false, SHIMMABLE_TEST_PAGE_3);
+
+  Services.prefs.clearUserPref(TRACKING_PREF);
+});
+
+add_task(async function test_shim_disabled_overridden_by_pref() {
+  Services.prefs.setBoolPref(TRACKING_PREF, true);
+
+  await testShimDoesNotRun(false, SHIMMABLE_TEST_PAGE_2);
+
+  Services.prefs.setBoolPref(DISABLE_SHIM2_PREF, false);
+
+  await testShimRuns(SHIMMABLE_TEST_PAGE_2);
+
+  Services.prefs.clearUserPref(TRACKING_PREF);
+  Services.prefs.clearUserPref(DISABLE_SHIM2_PREF);
+});
+
+add_task(async function test_shim() {
+  // Test that a shim which only runs in strict mode works, and that it
+  // is permitted to opt into showing normally-blocked tracking content.
+
+  Services.prefs.setBoolPref(TRACKING_PREF, true);
+
+  await testShimRuns(SHIMMABLE_TEST_PAGE);
+
+  // test that if the user opts in on one domain, they will still have to opt
+  // in on another domain which embeds an iframe to the first one.
+
+  await testShimRuns(EMBEDDING_TEST_PAGE, 0, false, false);
+
+  Services.prefs.clearUserPref(TRACKING_PREF);
+});
diff --git a/browser/extensions/webcompat/tests/browser/head.js b/browser/extensions/webcompat/tests/browser/head.js
new file mode 100644
index 0000000000..7fe8c3c171
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/head.js
@@ -0,0 +1,140 @@
+"use strict";
+
+const TEST_ROOT = getRootDirectory(gTestPath).replace(
+  "chrome://mochitests/content",
+  "http://example.com"
+);
+
+const THIRD_PARTY_ROOT = getRootDirectory(gTestPath).replace(
+  "chrome://mochitests/content",
+  "http://example.net"
+);
+
+const SHIMMABLE_TEST_PAGE = `${TEST_ROOT}shims_test.html`;
+const SHIMMABLE_TEST_PAGE_2 = `${TEST_ROOT}shims_test_2.html`;
+const SHIMMABLE_TEST_PAGE_3 = `${TEST_ROOT}shims_test_3.html`;
+const EMBEDDING_TEST_PAGE = `${THIRD_PARTY_ROOT}iframe_test.html`;
+
+const BLOCKED_TRACKER_URL =
+  "//trackertest.org/tests/toolkit/components/url-classifier/tests/mochitest/evil.js";
+
+const DISABLE_SHIM1_PREF = "extensions.webcompat.disabled_shims.MochitestShim";
+const DISABLE_SHIM2_PREF = "extensions.webcompat.disabled_shims.MochitestShim2";
+const DISABLE_SHIM3_PREF = "extensions.webcompat.disabled_shims.MochitestShim3";
+const DISABLE_SHIM4_PREF = "extensions.webcompat.disabled_shims.MochitestShim4";
+const GLOBAL_PREF = "extensions.webcompat.enable_shims";
+const TRACKING_PREF = "privacy.trackingprotection.enabled";
+
+const { UrlClassifierTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/UrlClassifierTestUtils.sys.mjs"
+);
+
+async function testShimRuns(
+  testPage,
+  frame,
+  trackersAllowed = true,
+  expectOptIn = true
+) {
+  const tab = await BrowserTestUtils.openNewForegroundTab({
+    gBrowser,
+    opening: testPage,
+    waitForLoad: true,
+  });
+
+  const TrackingProtection =
+    tab.ownerGlobal.gProtectionsHandler.blockers.TrackingProtection;
+  ok(TrackingProtection, "TP is attached to the tab");
+  ok(TrackingProtection.enabled, "TP is enabled");
+
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [[trackersAllowed, BLOCKED_TRACKER_URL, expectOptIn], frame],
+    async (args, _frame) => {
+      const window = _frame === undefined ? content : content.frames[_frame];
+
+      await SpecialPowers.spawn(
+        window,
+        args,
+        async (_trackersAllowed, trackerUrl, _expectOptIn) => {
+          const shimResult = await content.wrappedJSObject.shimPromise;
+          is("shimmed", shimResult, "Shim activated");
+
+          const optInResult = await content.wrappedJSObject.optInPromise;
+          is(_expectOptIn, optInResult, "Shim allowed opt in if appropriate");
+
+          const o = content.document.getElementById("shims");
+          const cl = o.classList;
+          const opts = JSON.parse(o.innerText);
+          is(
+            undefined,
+            opts.branchValue,
+            "Shim script did not receive option for other branch"
+          );
+          is(
+            undefined,
+            opts.platformValue,
+            "Shim script did not receive option for other platform"
+          );
+          is(
+            true,
+            opts.simpleOption,
+            "Shim script received simple option correctly"
+          );
+          ok(opts.complexOption, "Shim script received complex option");
+          is(
+            1,
+            opts.complexOption.a,
+            "Shim script received complex options correctly #1"
+          );
+          is(
+            "test",
+            opts.complexOption.b,
+            "Shim script received complex options correctly #2"
+          );
+          ok(cl.contains("green"), "Shim affected page correctly");
+        }
+      );
+    }
+  );
+
+  await BrowserTestUtils.removeTab(tab);
+}
+
+async function testShimDoesNotRun(
+  trackersAllowed = false,
+  testPage = SHIMMABLE_TEST_PAGE
+) {
+  const tab = await BrowserTestUtils.openNewForegroundTab({
+    gBrowser,
+    opening: testPage,
+    waitForLoad: true,
+  });
+
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [trackersAllowed, BLOCKED_TRACKER_URL],
+    async (_trackersAllowed, trackerUrl) => {
+      const shimResult = await content.wrappedJSObject.shimPromise;
+      is("did not shim", shimResult, "Shim did not activate");
+
+      ok(
+        !content.document.getElementById("shims").classList.contains("green"),
+        "Shim script did not run"
+      );
+
+      is(
+        _trackersAllowed ? "ALLOWED" : "BLOCKED",
+        await new Promise(resolve => {
+          const s = content.document.createElement("script");
+          s.src = trackerUrl;
+          s.onload = () => resolve("ALLOWED");
+          s.onerror = () => resolve("BLOCKED");
+          content.document.head.appendChild(s);
+        }),
+        "Normally-blocked resources blocked if appropriate"
+      );
+    }
+  );
+
+  await BrowserTestUtils.removeTab(tab);
+}
diff --git a/browser/extensions/webcompat/tests/browser/iframe_test.html b/browser/extensions/webcompat/tests/browser/iframe_test.html
new file mode 100644
index 0000000000..baf1ee9024
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/iframe_test.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf8" />
+    <script>
+      window.shimPromise = new Promise(resolve => {
+        window.shimPromiseResolve = resolve;
+      });
+      window.optInPromise = new Promise(resolve => {
+        window.optInPromiseResolve = resolve;
+      });
+    </script>
+  </head>
+  <body>
+    <iframe
+      src="http://example.com/browser/browser/extensions/webcompat/tests/browser/shims_test.html"
+    ></iframe>
+  </body>
+</html>
diff --git a/browser/extensions/webcompat/tests/browser/shims_test.html b/browser/extensions/webcompat/tests/browser/shims_test.html
new file mode 100644
index 0000000000..ebe877316d
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/shims_test.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf8" />
+    <script>
+      window.shimPromise = new Promise(resolve => {
+        window.shimPromiseResolve = resolve;
+      });
+      window.optInPromise = new Promise(resolve => {
+        window.optInPromiseResolve = resolve;
+      });
+    </script>
+    <script
+      onerror="window.shimPromiseResolve('error')"
+      src="shims_test.js"
+    ></script>
+  </head>
+  <body>
+    <div id="shims"></div>
+  </body>
+</html>
diff --git a/browser/extensions/webcompat/tests/browser/shims_test.js b/browser/extensions/webcompat/tests/browser/shims_test.js
new file mode 100644
index 0000000000..4a55bee7ed
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/shims_test.js
@@ -0,0 +1,11 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+if (window.doingOptIn) {
+  window.optInPromiseResolve(true);
+} else {
+  window.shimPromiseResolve("did not shim");
+}
diff --git a/browser/extensions/webcompat/tests/browser/shims_test_2.html b/browser/extensions/webcompat/tests/browser/shims_test_2.html
new file mode 100644
index 0000000000..b080f74f6e
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/shims_test_2.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf8" />
+    <script>
+      window.shimPromise = new Promise(resolve => {
+        window.shimPromiseResolve = resolve;
+      });
+      window.optInPromise = new Promise(resolve => {
+        window.optInPromiseResolve = resolve;
+      });
+    </script>
+    <script
+      onerror="window.shimPromiseResolve('error')"
+      src="shims_test_2.js"
+    ></script>
+  </head>
+  <body>
+    <div id="shims"></div>
+  </body>
+</html>
diff --git a/browser/extensions/webcompat/tests/browser/shims_test_2.js b/browser/extensions/webcompat/tests/browser/shims_test_2.js
new file mode 100644
index 0000000000..4a55bee7ed
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/shims_test_2.js
@@ -0,0 +1,11 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+if (window.doingOptIn) {
+  window.optInPromiseResolve(true);
+} else {
+  window.shimPromiseResolve("did not shim");
+}
diff --git a/browser/extensions/webcompat/tests/browser/shims_test_3.html b/browser/extensions/webcompat/tests/browser/shims_test_3.html
new file mode 100644
index 0000000000..bcb6f12043
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/shims_test_3.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf8" />
+    <script>
+      window.shimPromise = new Promise(resolve => {
+        window.shimPromiseResolve = resolve;
+      });
+      window.optInPromise = new Promise(resolve => {
+        window.optInPromiseResolve = resolve;
+      });
+    </script>
+    <script
+      onerror="window.shimPromiseResolve('error')"
+      src="shims_test_3.js"
+    ></script>
+  </head>
+  <body>
+    <div id="shims"></div>
+  </body>
+</html>
diff --git a/browser/extensions/webcompat/tests/browser/shims_test_3.js b/browser/extensions/webcompat/tests/browser/shims_test_3.js
new file mode 100644
index 0000000000..9acb6cdcf1
--- /dev/null
+++ b/browser/extensions/webcompat/tests/browser/shims_test_3.js
@@ -0,0 +1,7 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+window.shimPromiseResolve("did not shim");