deleted file mode 100644
--- a/browser/extensions/e10srollout/bootstrap.js
+++ /dev/null
@@ -1,306 +0,0 @@
-/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* 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";
-
-const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
-
-Cu.import("resource://gre/modules/Services.jsm");
-Cu.import("resource://gre/modules/UpdateUtils.jsm");
-Cu.import("resource://gre/modules/AppConstants.jsm");
-Cu.import("resource://gre/modules/TelemetryEnvironment.jsm");
-
-// The amount of people to be part of e10s
-const TEST_THRESHOLD = {
-  "beta": 0.9,  // 90%
-  "release": 1.0,  // 100%
-  "esr": 1.0,  // 100%
-};
-
-// If a user qualifies for the e10s-multi experiement, this is how many
-// content processes to use and whether to allow addons for the experiment.
-const MULTI_EXPERIMENT = {
-  "beta": { buckets: { 4: 1 }, // 4 processes: 100%
-
-            // The extensions code only allows webextensions and legacy-style
-            // extensions that have been verified to work with multi.
-            // Therefore, we can allow all extensions.
-            addonsDisableExperiment(prefix) { return false; } },
-
-  "release": { buckets: { 4: 1 }, // 4 processes: 100%
-
-               // See the comment above the "beta" addonsDisableExperiment.
-               addonsDisableExperiment(prefix) { return false; } }
-};
-
-const ADDON_ROLLOUT_POLICY = {
-  "beta": "50allmpc",
-  "release": "50allmpc",
-  "esr": "esrA", // WebExtensions and Addons with mpc=true
-};
-
-if (AppConstants.RELEASE_OR_BETA) {
-  // Bug 1348576 - e10s is never enabled for non-official release builds
-  // This is hacky, but the problem it solves is the following:
-  // the e10s rollout is controlled by the channel name, which
-  // is the only way to distinguish between Beta and Release.
-  // However, non-official release builds (like the ones done by distros
-  // to ship Firefox on their package managers) do not set a value
-  // for the release channel, which gets them to the default value
-  // of.. (drumroll) "default".
-  // But we can't just always configure the same settings for the
-  // "default" channel because that's also the name that a locally
-  // built Firefox gets, and e10s is managed in a different way
-  // there (directly by prefs, on Nightly and Aurora).
-  TEST_THRESHOLD.default = TEST_THRESHOLD.release;
-  ADDON_ROLLOUT_POLICY.default = ADDON_ROLLOUT_POLICY.release;
-}
-
-
-const PREF_COHORT_SAMPLE       = "e10s.rollout.cohortSample";
-const PREF_COHORT_NAME         = "e10s.rollout.cohort";
-const PREF_E10S_OPTED_IN       = "browser.tabs.remote.autostart";
-const PREF_E10S_FORCE_ENABLED  = "browser.tabs.remote.force-enable";
-const PREF_E10S_FORCE_DISABLED = "browser.tabs.remote.force-disable";
-const PREF_TOGGLE_E10S         = "browser.tabs.remote.autostart.2";
-const PREF_E10S_ADDON_POLICY   = "extensions.e10s.rollout.policy";
-const PREF_E10S_ADDON_BLOCKLIST = "extensions.e10s.rollout.blocklist";
-const PREF_E10S_HAS_NONEXEMPT_ADDON = "extensions.e10s.rollout.hasAddon";
-const PREF_E10S_MULTI_OPTOUT   = "dom.ipc.multiOptOut";
-const PREF_E10S_PROCESSCOUNT   = "dom.ipc.processCount";
-const PREF_USE_DEFAULT_PERF_SETTINGS = "browser.preferences.defaultPerformanceSettings.enabled";
-const PREF_E10S_MULTI_ADDON_BLOCKS = "extensions.e10sMultiBlocksEnabling";
-const PREF_E10S_MULTI_BLOCKED_BY_ADDONS = "extensions.e10sMultiBlockedByAddons";
-
-function startup() {
-  // In theory we only need to run this once (on install()), but
-  // it's better to also run it on every startup. If the user has
-  // made manual changes to the prefs, this will keep the data
-  // reported more accurate.
-  // It's also fine (and preferred) to just do it here on startup
-  // (instead of observing prefs), because e10s takes a restart
-  // to take effect, so we keep the data based on how it was when
-  // the session started.
-  defineCohort();
-}
-
-function install() {
-  defineCohort();
-}
-
-let cohortDefinedOnThisSession = false;
-
-function defineCohort() {
-  // Avoid running twice when it was called by install() first
-  if (cohortDefinedOnThisSession) {
-    return;
-  }
-  cohortDefinedOnThisSession = true;
-
-  let updateChannel = UpdateUtils.getUpdateChannel(false);
-  if (!(updateChannel in TEST_THRESHOLD)) {
-    setCohort("unsupportedChannel");
-    return;
-  }
-
-  let addonPolicy = "unknown";
-  if (updateChannel in ADDON_ROLLOUT_POLICY) {
-    addonPolicy = ADDON_ROLLOUT_POLICY[updateChannel];
-    Services.prefs.setStringPref(PREF_E10S_ADDON_POLICY, addonPolicy);
-
-    // This is also the proper place to set the blocklist pref
-    // in case it is necessary.
-    Services.prefs.setStringPref(PREF_E10S_ADDON_BLOCKLIST, "");
-  } else {
-    Services.prefs.clearUserPref(PREF_E10S_ADDON_POLICY);
-  }
-
-  let userOptedOut = optedOut();
-  let userOptedIn = optedIn();
-  let disqualified = (Services.appinfo.multiprocessBlockPolicy != 0);
-  let testThreshold = TEST_THRESHOLD[updateChannel];
-  let testGroup = (getUserSample(false) < testThreshold);
-  let hasNonExemptAddon = Services.prefs.getBoolPref(PREF_E10S_HAS_NONEXEMPT_ADDON, false);
-  let temporaryDisqualification = getTemporaryDisqualification();
-  let temporaryQualification = getTemporaryQualification();
-
-  let cohortPrefix = "";
-  if (disqualified) {
-    cohortPrefix = "disqualified-";
-  } else if (hasNonExemptAddon) {
-    cohortPrefix = `addons-set${addonPolicy}-`;
-  }
-
-  let eligibleForMulti = false;
-  if (userOptedOut.e10s || userOptedOut.multi) {
-    // If we detected that the user opted out either for multi or e10s, then
-    // the proper prefs must already be set.
-    setCohort("optedOut");
-  } else if (userOptedIn.e10s) {
-    eligibleForMulti = true;
-    setCohort("optedIn");
-  } else if (temporaryDisqualification != "") {
-    // Users who are disqualified by the backend (from multiprocessBlockPolicy)
-    // can be put into either the test or control groups, because e10s will
-    // still be denied by the backend, which is useful so that the E10S_STATUS
-    // telemetry probe can be correctly set.
-
-    // For these volatile disqualification reasons, however, we must not try
-    // to activate e10s because the backend doesn't know about it. E10S_STATUS
-    // here will be accumulated as "2 - Disabled", which is fine too.
-    Services.prefs.clearUserPref(PREF_TOGGLE_E10S);
-    Services.prefs.clearUserPref(PREF_E10S_PROCESSCOUNT + ".web");
-    setCohort(`temp-disqualified-${temporaryDisqualification}`);
-  } else if (!disqualified && testThreshold < 1.0 &&
-             temporaryQualification != "") {
-    // Users who are qualified for e10s and on channels where some population
-    // would not receive e10s can be pushed into e10s anyway via a temporary
-    // qualification which overrides the user sample value when non-empty.
-    Services.prefs.setBoolPref(PREF_TOGGLE_E10S, true);
-    eligibleForMulti = true;
-    setCohort(`temp-qualified-${temporaryQualification}`);
-  } else if (testGroup) {
-    Services.prefs.setBoolPref(PREF_TOGGLE_E10S, true);
-    eligibleForMulti = true;
-    setCohort(`${cohortPrefix}test`);
-  } else {
-    Services.prefs.clearUserPref(PREF_TOGGLE_E10S);
-    Services.prefs.clearUserPref(PREF_E10S_PROCESSCOUNT + ".web");
-    setCohort(`${cohortPrefix}control`);
-  }
-
-  // Now determine if this user should be in the e10s-multi experiment.
-  // - We only run the experiment on channels defined in MULTI_EXPERIMENT.
-  // - If this experiment doesn't allow addons and we have a cohort prefix
-  //   (i.e. there's at least one addon installed) we stop here.
-  // - We decided above whether this user qualifies for the experiment.
-  // - If the user already opted into multi, then their prefs are already set
-  //   correctly, we're done.
-  // - If the user has addons that disqualify them for multi, leave them with
-  //   the default number of content processes (1 on beta) but still in the
-  //   test cohort.
-  if (!(updateChannel in MULTI_EXPERIMENT) ||
-      MULTI_EXPERIMENT[updateChannel].addonsDisableExperiment(cohortPrefix) ||
-      !eligibleForMulti ||
-      userOptedIn.multi ||
-      disqualified) {
-    Services.prefs.clearUserPref(PREF_E10S_PROCESSCOUNT + ".web");
-    return;
-  }
-
-  // If we got here with a cohortPrefix, it must be "addons-set50allmpc-",
-  // which means that there's at least one add-on installed. If
-  // getAddonsDisqualifyForMulti returns false, that means that all installed
-  // addons are webextension based, so note that in the cohort name.
-  if (cohortPrefix && !getAddonsDisqualifyForMulti()) {
-    cohortPrefix = "webextensions-";
-  }
-
-  // The user is in the multi experiment!
-  // Decide how many content processes to use for this user.
-  let buckets = MULTI_EXPERIMENT[updateChannel].buckets;
-
-  let multiUserSample = getUserSample(true);
-  for (let sampleName of Object.getOwnPropertyNames(buckets)) {
-    if (multiUserSample < buckets[sampleName]) {
-      // NB: Coerce sampleName to an integer because this is an integer pref.
-      Services.prefs.setIntPref(PREF_E10S_PROCESSCOUNT + ".web", +sampleName);
-      setCohort(`${cohortPrefix}multiBucket${sampleName}`);
-      break;
-    }
-  }
-}
-
-function shutdown(data, reason) {
-}
-
-function uninstall() {
-}
-
-function getUserSample(multi) {
-  let pref = multi ? (PREF_COHORT_SAMPLE + ".multi") : PREF_COHORT_SAMPLE;
-  let prefType = Services.prefs.getPrefType(pref);
-
-  if (prefType == Ci.nsIPrefBranch.PREF_STRING) {
-    return parseFloat(Services.prefs.getStringPref(pref), 10);
-  }
-
-  let value = 0.0;
-  if (prefType == Ci.nsIPrefBranch.PREF_INT) {
-    // convert old integer value
-    value = Services.prefs.getIntPref(pref) / 100;
-  } else {
-    value = Math.random();
-  }
-
-  Services.prefs.setStringPref(pref, value.toString().substr(0, 8));
-  return value;
-}
-
-function setCohort(cohortName) {
-  Services.prefs.setStringPref(PREF_COHORT_NAME, cohortName);
-  if (cohortName != "unsupportedChannel") {
-    TelemetryEnvironment.setExperimentActive("e10sCohort", cohortName);
-  }
-  try {
-    if (Ci.nsICrashReporter) {
-      Services.appinfo.QueryInterface(Ci.nsICrashReporter).annotateCrashReport("E10SCohort", cohortName);
-    }
-  } catch (e) {}
-}
-
-function optedIn() {
-  let e10s = Services.prefs.getBoolPref(PREF_E10S_OPTED_IN, false) ||
-             Services.prefs.getBoolPref(PREF_E10S_FORCE_ENABLED, false);
-  let multi = Services.prefs.prefHasUserValue(PREF_E10S_PROCESSCOUNT) ||
-             !Services.prefs.getBoolPref(PREF_USE_DEFAULT_PERF_SETTINGS, true);
-  return { e10s, multi };
-}
-
-function optedOut() {
-  // Users can also opt-out by toggling back the pref to false.
-  // If they reset the pref instead they might be re-enabled if
-  // they are still part of the threshold.
-  let e10s = Services.prefs.getBoolPref(PREF_E10S_FORCE_DISABLED, false) ||
-               (Services.prefs.prefHasUserValue(PREF_TOGGLE_E10S) &&
-                Services.prefs.getBoolPref(PREF_TOGGLE_E10S) == false);
-  let multi = Services.prefs.getIntPref(PREF_E10S_MULTI_OPTOUT, 0) >=
-              Services.appinfo.E10S_MULTI_EXPERIMENT;
-  return { e10s, multi };
-}
-
-/* If this function returns a non-empty string, it
- * means that this particular user should be temporarily
- * disqualified due to some particular reason.
- * If a user shouldn't be disqualified, then an empty
- * string must be returned.
- */
-function getTemporaryDisqualification() {
-  return "";
-}
-
-/* If this function returns a non-empty string, it
- * means that this particular user should be temporarily
- * qualified due to some particular reason.
- * If a user shouldn't be qualified, then an empty
- * string must be returned.
- */
-function getTemporaryQualification() {
-  // Whenever the DevTools toolbox is opened for the first time in a release, it
-  // records this fact in the following pref as part of the DevTools telemetry
-  // system.  If this pref is set, then it means the user has opened DevTools at
-  // some point in time.
-  const PREF_OPENED_DEVTOOLS = "devtools.telemetry.tools.opened.version";
-  let hasOpenedDevTools = Services.prefs.prefHasUserValue(PREF_OPENED_DEVTOOLS);
-  if (hasOpenedDevTools) {
-    return "devtools";
-  }
-
-  return "";
-}
-
-function getAddonsDisqualifyForMulti() {
-  return Services.prefs.getBoolPref("extensions.e10sMultiBlocksEnabling", false) &&
-         Services.prefs.getBoolPref("extensions.e10sMultiBlockedByAddons", false);
-}

deleted file mode 100644
--- a/browser/extensions/e10srollout/install.rdf.in
+++ /dev/null
@@ -1,32 +0,0 @@
-<?xml version="1.0"?>
-<!-- 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/. -->
-
-#filter substitution
-
-<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
-     xmlns:em="http://www.mozilla.org/2004/em-rdf#">
-
-  <Description about="urn:mozilla:install-manifest">
-    <em:id>e10srollout@mozilla.org</em:id>
-    <em:version>3.05</em:version>
-    <em:type>2</em:type>
-    <em:bootstrap>true</em:bootstrap>
-    <em:multiprocessCompatible>true</em:multiprocessCompatible>
-
-    <!-- Target Application this theme can install into,
-        with minimum and maximum supported versions. -->
-    <em:targetApplication>
-      <Description>
-        <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
-        <em:minVersion>@MOZ_APP_VERSION@</em:minVersion>
-        <em:maxVersion>@MOZ_APP_MAXVERSION@</em:maxVersion>
-      </Description>
-    </em:targetApplication>
-
-    <!-- Front End MetaData -->
-    <em:name>Multi-process staged rollout</em:name>
-    <em:description>Staged rollout of Firefox multi-process feature.</em:description>
-  </Description>
-</RDF>

deleted file mode 100644
--- a/browser/extensions/e10srollout/moz.build
+++ /dev/null
@@ -1,19 +0,0 @@
-# -*- 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/.
-
-with Files("**"):
-    BUG_COMPONENT = ("Core", "DOM: Content Processes")
-
-DEFINES['MOZ_APP_VERSION'] = CONFIG['MOZ_APP_VERSION']
-DEFINES['MOZ_APP_MAXVERSION'] = CONFIG['MOZ_APP_MAXVERSION']
-
-FINAL_TARGET_FILES.features['e10srollout@mozilla.org'] += [
-  'bootstrap.js'
-]
-
-FINAL_TARGET_PP_FILES.features['e10srollout@mozilla.org'] += [
-  'install.rdf.in'
-]

--- a/browser/extensions/moz.build
+++ b/browser/extensions/moz.build
@@ -2,17 +2,16 @@
 # 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/.
 
 DIRS += [
     'activity-stream',
     'aushelper',
-    'e10srollout',
     'followonsearch',
     'formautofill',
     'onboarding',
     'pdfjs',
     'pocket',
     'screenshots',
     'shield-recipe-client',
     'webcompat',

--- a/testing/talos/talos/xtalos/xperf_whitelist.json
+++ b/testing/talos/talos/xtalos/xperf_whitelist.json
@@ -2,17 +2,16 @@
  "C:\\$Mft": {"ignore": true},
  "C:\\$Extend\\$UsnJrnl:$J": {"ignore": true},
  "C:\\Windows\\Prefetch\\{prefetch}.pf": {"ignore": true},
  "C:\\$Secure": {"ignore": true},
  "C:\\$logfile": {"ignore": true},
  "{firefox}\\omni.ja": {"mincount": 0, "maxcount": 46, "minbytes": 0, "maxbytes": 3014656},
  "{firefox}\\browser\\omni.ja": {"mincount": 0, "maxcount": 28, "minbytes": 0, "maxbytes": 1835008},
  "{firefox}\\browser\\features\\aushelper@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
- "{firefox}\\browser\\features\\e10srollout@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\flyweb@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\formautofill@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\loop@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\firefox@getpocket.com.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\presentation@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\webcompat@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\webcompat-reporter@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},
  "{firefox}\\browser\\features\\shield-recipe-client@mozilla.org.xpi": {"mincount": 0, "maxcount": 100, "minbytes": 0, "maxbytes": 10000000},