Adding upstream version 110.0.1.upstream/110.0.1upstream

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

11 files changed, 2137 insertions, 0 deletions

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..56a95aa102
--- /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..793fa03139
--- /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..fcba62f4ce
--- /dev/null
+++ b/browser/extensions/webcompat/lib/shims.js
@@ -0,0 +1,1045 @@
+/* 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 ${frameId}`);
+    }
+    return undefined;
+  }
+}
+
+module.exports = Shims;
diff --git a/browser/extensions/webcompat/lib/ua_helpers.js b/browser/extensions/webcompat/lib/ua_helpers.js
new file mode 100644
index 0000000000..5d09e7f31d
--- /dev/null
+++ b/browser/extensions/webcompat/lib/ua_helpers.js
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/* globals exportFunction, module */
+
+var UAHelpers = {
+  _deviceAppropriateChromeUAs: {},
+  getDeviceAppropriateChromeUA(config = {}) {
+    const { version = "103.0.5060.71", androidDevice, desktopOS } = config;
+    const key = `${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;