Adding upstream version 124.0.1.upstream/124.0.1

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

27 files changed, 1211 insertions, 0 deletions

diff --git a/testing/profiles/base/extensions/README.txt b/testing/profiles/base/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/base/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/base/user.js b/testing/profiles/base/user.js
new file mode 100644
index 0000000000..78a9d95a93
--- /dev/null
+++ b/testing/profiles/base/user.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/. */
+
+// This is useful for testing a pref on try.
+/* globals user_pref */
+// ensure webrender is set (and we don't need MOZ_WEBRENDER env variable)
+user_pref("gfx.webrender.all", true);
+user_pref("dom.input_events.security.minNumTicks", 0);
+user_pref("dom.input_events.security.minTimeElapsedInMS", 0);
+
+// Set address autofill to true for tests
+user_pref("extensions.formautofill.addresses.experiments.enabled", true);
\ No newline at end of file
diff --git a/testing/profiles/common/extensions/README.txt b/testing/profiles/common/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/common/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/common/user.js b/testing/profiles/common/user.js
new file mode 100644
index 0000000000..5613898b7b
--- /dev/null
+++ b/testing/profiles/common/user.js
@@ -0,0 +1,91 @@
+/* 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/. */
+
+// Common preferences file used by both unittest and perf harnesses.
+/* globals user_pref */
+user_pref("app.update.checkInstallTime", false);
+user_pref("app.update.disabledForTesting", true);
+user_pref("browser.chrome.guess_favicon", false);
+user_pref("browser.dom.window.dump.enabled", true);
+user_pref("devtools.console.stdout.chrome", true);
+// asrouter expects a plain object or null
+user_pref("browser.newtabpage.activity-stream.asrouter.providers.cfr", "null");
+user_pref("browser.newtabpage.activity-stream.asrouter.providers.message-groups", "null");
+user_pref("browser.newtabpage.activity-stream.asrouter.providers.whats-new-panel", "null");
+user_pref("browser.newtabpage.activity-stream.asrouter.providers.messaging-experiments", "null");
+user_pref("browser.newtabpage.activity-stream.feeds.system.topstories", false);
+user_pref("browser.newtabpage.activity-stream.tippyTop.service.endpoint", "");
+user_pref("browser.newtabpage.activity-stream.discoverystream.config", "[]");
+
+// For Activity Stream firstrun page, use an empty string to avoid fetching.
+user_pref("browser.newtabpage.activity-stream.fxaccounts.endpoint", "");
+// Background thumbnails in particular cause grief, and disabling thumbnails
+// in general can't hurt - we re-enable them when tests need them.
+user_pref("browser.pagethumbnails.capturing_disabled", true);
+// Tell the search service we are running in the US.  This also has the desired
+// side-effect of preventing our geoip lookup.
+user_pref("browser.search.region", "US");
+// disable infobar for tests
+user_pref("browser.search.removeEngineInfobar.enabled", false);
+// Disable webapp updates.  Yes, it is supposed to be an integer.
+user_pref("browser.webapps.checkForUpdates", 0);
+// We do not wish to display datareporting policy notifications as it might
+// cause other tests to fail. Tests that wish to test the notification functionality
+// should explicitly disable this pref.
+user_pref("datareporting.policy.dataSubmissionPolicyBypassNotification", true);
+user_pref("dom.max_chrome_script_run_time", 0);
+user_pref("dom.max_script_run_time", 0); // no slow script dialogs
+user_pref("dom.send_after_paint_to_content", true);
+// Only load extensions from the application and user profile
+// AddonManager.SCOPE_PROFILE + AddonManager.SCOPE_APPLICATION
+user_pref("extensions.enabledScopes", 5);
+user_pref("extensions.experiments.enabled", true);
+// Turn off extension updates so they don't bother tests
+user_pref("extensions.update.enabled", false);
+// Prevent network access for recommendations by default. The payload is {"results":[]}.
+user_pref("extensions.getAddons.discovery.api_url", "data:;base64,eyJyZXN1bHRzIjpbXX0%3D");
+// Treat WebExtension API/schema warnings as errors.
+user_pref("extensions.webextensions.warnings-as-errors", true);
+// Disable useragent updates.
+user_pref("general.useragent.updates.enabled", false);
+user_pref("hangmonitor.timeout", 0); // no hang monitor
+user_pref("media.gmp-manager.updateEnabled", false);
+// Don't do network connections for mitm priming
+user_pref("security.certerrors.mitm.priming.enabled", false);
+// Enable some dangerous features for test code. :-(
+user_pref("security.turn_off_all_security_so_that_viruses_can_take_over_this_computer", true);
+user_pref("xpinstall.signatures.required", false);
+// Prevent Remote Settings to issue non local connections.
+user_pref("services.settings.server", "data:,#remote-settings-dummy/v1");
+// Ensure autoplay is enabled for all platforms.
+user_pref("media.autoplay.default", 0); // 0=Allowed, 1=Blocked, 2=Prompt
+user_pref("media.autoplay.blocking_policy", 0);
+user_pref("media.autoplay.ask-permission", false);
+user_pref("media.allowed-to-play.enabled", true);
+// Ensure media can always play without delay
+user_pref("media.block-autoplay-until-in-foreground", false);
+user_pref("toolkit.telemetry.coverage.endpoint.base", "http://localhost");
+// Don't ask for a request in testing unless explicitly set this as true.
+user_pref("media.geckoview.autoplay.request", false);
+user_pref("geo.provider.network.compare.url", "");
+user_pref("browser.region.network.url", "");
+// Do not unload tabs on low memory when testing
+user_pref("browser.tabs.unloadOnLowMemory", false);
+// Don't pull Top Sites content from the network
+user_pref("browser.topsites.contile.enabled", false);
+// Don't pull sponsored Top Sites content from the network
+user_pref("browser.newtabpage.activity-stream.showSponsoredTopSites", false);
+// Default Glean to "record but don't report" mode. Docs:
+// https://firefox-source-docs.mozilla.org/toolkit/components/glean/dev/preferences.html
+user_pref("telemetry.fog.test.localhost_port", -1);
+// Disable overlay scrollbars on GTK for testing. A bunch of tests (specially
+// mochitests) assume scrollbars take space. We disable them on macOS (where
+// overlay is also the default) at the system level as well, so this is
+// probably ok.
+//
+// We test the relevant overlay scrollbar code-paths on Android.
+user_pref("widget.gtk.overlay-scrollbars.enabled", false);
+// Generally, we don't want daily idle tasks run during tests. Specific tests
+// can re-enable if needed.
+user_pref("idle.lastDailyNotification", -1);
diff --git a/testing/profiles/geckoview-junit/user.js b/testing/profiles/geckoview-junit/user.js
new file mode 100644
index 0000000000..01f1045327
--- /dev/null
+++ b/testing/profiles/geckoview-junit/user.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/. */
+
+// Base preferences file used by the mochitest
+/* globals user_pref */
+/* eslint quotes: 0 */
diff --git a/testing/profiles/mochitest/user.js b/testing/profiles/mochitest/user.js
new file mode 100644
index 0000000000..3b8a485045
--- /dev/null
+++ b/testing/profiles/mochitest/user.js
@@ -0,0 +1,24 @@
+// Base preferences file used by the mochitest
+/* globals user_pref */
+/* eslint quotes: 0 */
+
+// Don't restore the last open set of tabs if the browser has crashed
+// or if the profile folder is re-used after an exit(0) fast shutdown.
+user_pref("browser.sessionstore.resume_from_crash", false);
+
+// Better stacks for errors.
+user_pref("javascript.options.asyncstack_capture_debuggee_only", false);
+
+// Don't enable paint suppression when the background is unknown. While paint
+// is suppressed, synthetic click events and co. go to the old page, which can
+// be confusing for tests that send click events before the first paint.
+user_pref("nglayout.initialpaint.unsuppress_with_no_background", true);
+
+// Disable prefers-reduced-motion to ensure that smooth scrolls can be tested.
+user_pref("general.smoothScroll", true);
+
+// Disable secure context pref for testing storage access API.
+// Related Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1840902.
+// Plan to remove this pref since all tests must be compliant with the
+// storage access API spec for secure contexts.
+user_pref("dom.storage_access.dont_grant_insecure_contexts", false);
diff --git a/testing/profiles/moz.build b/testing/profiles/moz.build
new file mode 100644
index 0000000000..579b510d4d
--- /dev/null
+++ b/testing/profiles/moz.build
@@ -0,0 +1,26 @@
+# -*- 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/.
+
+profile_files = [
+    "base/*",
+    "common/*",
+    "geckoview-junit/*",
+    "mochitest/*",
+    "perf/*",
+    "profiles.json",
+    "profileserver/*",
+    "reftest/*",
+    "unittest-features/*",
+    "unittest-required/*",
+    "web-platform/*",
+]
+
+TEST_HARNESS_FILES.reftest.profile_data += profile_files
+TEST_HARNESS_FILES.testing.mochitest.profile_data += profile_files
+TEST_HARNESS_FILES["web-platform"].prefs += profile_files
+
+with Files("**"):
+    BUG_COMPONENT = ("Testing", "General")
diff --git a/testing/profiles/perf/extensions/README.txt b/testing/profiles/perf/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/perf/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/perf/user.js b/testing/profiles/perf/user.js
new file mode 100644
index 0000000000..9d5dce65bb
--- /dev/null
+++ b/testing/profiles/perf/user.js
@@ -0,0 +1,99 @@
+/* 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/. */
+
+// Base preferences file used by performance harnesses
+/* globals user_pref */
+user_pref("app.normandy.api_url", "https://127.0.0.1/selfsupport-dummy/");
+user_pref("browser.EULA.override", true);
+user_pref("browser.addon-watch.interval", -1); // Deactivate add-on watching
+// Disable Bookmark backups by default.
+user_pref("browser.bookmarks.max_backups", 0);
+user_pref("browser.cache.disk.smart_size.enabled", false);
+user_pref("browser.contentHandlers.types.0.uri", "http://127.0.0.1/rss?url=%s");
+user_pref("browser.contentHandlers.types.1.uri", "http://127.0.0.1/rss?url=%s");
+user_pref("browser.contentHandlers.types.2.uri", "http://127.0.0.1/rss?url=%s");
+user_pref("browser.contentHandlers.types.3.uri", "http://127.0.0.1/rss?url=%s");
+user_pref("browser.contentHandlers.types.4.uri", "http://127.0.0.1/rss?url=%s");
+user_pref("browser.contentHandlers.types.5.uri", "http://127.0.0.1/rss?url=%s");
+user_pref("browser.link.open_newwindow", 2);
+user_pref("browser.newtabpage.activity-stream.default.sites", "");
+user_pref("browser.newtabpage.activity-stream.telemetry", false);
+user_pref("browser.reader.detectedFirstArticle", true);
+user_pref("browser.safebrowsing.blockedURIs.enabled", false);
+user_pref("browser.safebrowsing.downloads.enabled", false);
+user_pref("browser.safebrowsing.downloads.remote.url", "http://127.0.0.1/safebrowsing-dummy/downloads");
+user_pref("browser.safebrowsing.malware.enabled", false);
+user_pref("browser.safebrowsing.phishing.enabled", false);
+user_pref("browser.safebrowsing.provider.google.gethashURL", "http://127.0.0.1/safebrowsing-dummy/gethash");
+user_pref("browser.safebrowsing.provider.google.updateURL", "http://127.0.0.1/safebrowsing-dummy/update");
+user_pref("browser.safebrowsing.provider.google4.gethashURL", "http://127.0.0.1/safebrowsing4-dummy/gethash");
+user_pref("browser.safebrowsing.provider.google4.updateURL", "http://127.0.0.1/safebrowsing4-dummy/update");
+user_pref("browser.safebrowsing.provider.mozilla.gethashURL", "http://127.0.0.1/safebrowsing-dummy/gethash");
+user_pref("browser.safebrowsing.provider.mozilla.updateURL", "http://127.0.0.1/safebrowsing-dummy/update");
+user_pref("browser.shell.checkDefaultBrowser", false);
+user_pref("browser.startup.couldRestoreSession.count", -1);
+user_pref("browser.warnOnQuit", false);
+user_pref("datareporting.healthreport.documentServerURI", "http://127.0.0.1/healthreport/");
+user_pref("devtools.chrome.enabled", false);
+user_pref("devtools.debugger.remote-enabled", false);
+user_pref("devtools.theme", "light");
+user_pref("devtools.timeline.enabled", false);
+user_pref("dom.allow_scripts_to_close_windows", true);
+user_pref("dom.disable_open_during_load", false);
+user_pref("dom.disable_window_flip", true);
+user_pref("dom.disable_window_move_resize", true);
+// required to prevent non-local access to push.services.mozilla.com
+user_pref("dom.push.connection.enabled", false);
+user_pref("extensions.autoDisableScopes", 10);
+user_pref("extensions.blocklist.enabled", false);
+user_pref("extensions.checkCompatibility", false);
+user_pref("extensions.getAddons.get.url", "http://127.0.0.1/extensions-dummy/repositoryGetURL");
+user_pref("extensions.getAddons.search.browseURL", "http://127.0.0.1/extensions-dummy/repositoryBrowseURL");
+user_pref("extensions.hotfix.url", "http://127.0.0.1/extensions-dummy/hotfixURL");
+user_pref("extensions.systemAddon.update.url", "http://127.0.0.1/dummy-system-addons.xml");
+user_pref("extensions.update.background.url", "http://127.0.0.1/extensions-dummy/updateBackgroundURL");
+user_pref("extensions.update.notifyUser", false);
+user_pref("extensions.update.url", "http://127.0.0.1/extensions-dummy/updateURL");
+user_pref("identity.fxaccounts.auth.uri", "https://127.0.0.1/fxa-dummy/");
+user_pref("identity.fxaccounts.migrateToDevEdition", false);
+user_pref("media.capturestream_hints.enabled", true);
+user_pref("media.gmp-manager.url", "http://127.0.0.1/gmpmanager-dummy/update.xml");
+// Don't block old libavcodec libraries when testing, because our test systems
+// cannot easily be upgraded.
+user_pref("media.libavcodec.allow-obsolete", true);
+user_pref("media.navigator.enabled", true);
+user_pref("media.navigator.permission.disabled", true);
+user_pref("media.peerconnection.enabled", true);
+// Set places maintenance far in the future (the maximum time possible in an
+// int32_t) to avoid it kicking in during tests. The maintenance can take a
+// relatively long time which may cause unnecessary intermittents and slow down
+// tests. This, like many things, will stop working correctly in 2038.
+user_pref("places.database.lastMaintenance", 2147483647);
+user_pref("privacy.reduceTimerPrecision", false); // Bug 1445243 - reduces precision of tests
+user_pref("privacy.trackingprotection.annotate_channels", false);
+user_pref("privacy.trackingprotection.enabled", false);
+user_pref("privacy.trackingprotection.introURL", "http://127.0.0.1/trackingprotection/tour");
+user_pref("privacy.trackingprotection.pbmode.enabled", false);
+user_pref("security.enable_java", false);
+user_pref("security.external_protocol_requires_permission", false);
+user_pref("security.fileuri.strict_origin_policy", false);
+user_pref("toolkit.telemetry.server", "https://127.0.0.1/telemetry-dummy/");
+user_pref("telemetry.fog.test.localhost_port", -1);
+// The telemetry system sometimes uses a separate program to send telemetry
+// pings, particularly in the case when Firefox is shutting down. The prefs above
+// prevent telemetry from being sent anywhere useful, but even so the process would
+// still be launched. Because performance tests start and stop the browser in rapid
+// succession, the pingsender calls from the previous test can run simultaneously with
+// the next test, increasing the system resource load and skewing the
+// results. So we just silently skip the pingsender invocation during perf tests.
+user_pref("toolkit.telemetry.testing.suppressPingsender", true);
+user_pref("startup.homepage_welcome_url", "");
+user_pref("startup.homepage_welcome_url.additional", "");
+// Ensures that system principal triggered about:blank load within the current
+// process to avoid performing process switches in the middle of warm load
+// tests (bug 1725270). Can be removed once non-about:blank intermediate pages
+// are used instead (bug 1724261).
+user_pref("browser.tabs.remote.systemTriggeredAboutBlankAnywhere", true);
+// Make sure speech dispatcher notification error does not impact how we measure visual perception in raptor tests
+user_pref("media.webspeech.synth.dont_notify_on_error", true);
diff --git a/testing/profiles/profile b/testing/profiles/profile
new file mode 100755
index 0000000000..7ca300a0bd
--- /dev/null
+++ b/testing/profiles/profile
@@ -0,0 +1,301 @@
+#!/bin/sh
+# -*- 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/.
+
+# The beginning of this script is both valid shell and valid python,
+# such that the script starts with the shell and is reexecuted python
+'''which' mach > /dev/null 2>&1 && exec mach python "$0" "$@" ||
+echo "mach not found, either add it to your \$PATH or run this script via ./mach python testing/profiles/profile"; exit  # noqa
+'''
+
+"""This script can be used to:
+
+    1) Show all preferences for a given suite
+    2) Diff preferences between two suites or profiles
+    3) Sort preference files alphabetically for a given profile
+
+To use, either make sure that `mach` is on your $PATH, or run:
+    $ ./mach python testing/profiles/profile <args>
+
+For more details run:
+    $ ./profile -- --help
+"""
+
+import json
+import os
+import sys
+from argparse import ArgumentParser
+from itertools import chain
+
+from mozprofile import Profile
+from mozprofile.prefs import Preferences
+
+here = os.path.abspath(os.path.dirname(__file__))
+
+try:
+    import jsondiff
+except ImportError:
+    from mozbuild.base import MozbuildObject
+    build = MozbuildObject.from_environment(cwd=here)
+    build.virtualenv_manager.install_pip_package("jsondiff")
+    import jsondiff
+
+
+FORMAT_STRINGS = {
+    'names': (
+        '{pref}',
+        '{pref}',
+    ),
+    'pretty': (
+        '{pref}: {value}',
+        '{pref}: {value_a} => {value_b}'
+    ),
+}
+
+
+def read_prefs(profile, pref_files=None):
+    """Read and return all preferences set in the given profile.
+
+    :param profile: Profile name relative to this `here`.
+    :returns: A dictionary of preferences set in the profile.
+    """
+    pref_files = pref_files or Profile.preference_file_names
+    prefs = {}
+    for name in pref_files:
+        path = os.path.join(here, profile, name)
+        if not os.path.isfile(path):
+            continue
+
+        try:
+            prefs.update(Preferences.read_json(path))
+        except ValueError:
+            prefs.update(Preferences.read_prefs(path))
+    return prefs
+
+
+def get_profiles(key):
+    """Return a list of profile names for key."""
+    with open(os.path.join(here, 'profiles.json'), 'r') as fh:
+        profiles = json.load(fh)
+
+    if '+' in key:
+        keys = key.split('+')
+    else:
+        keys = [key]
+
+    names = set()
+    for key in keys:
+        if key in profiles:
+            names.update(profiles[key])
+        elif os.path.isdir(os.path.join(here, key)):
+            names.add(key)
+
+    if not names:
+        raise ValueError('{} is not a recognized suite or profile'.format(key))
+    return names
+
+
+def read(key):
+    """Read preferences relevant to either a profile or suite.
+
+    :param key: Can either be the name of a profile, or the name of
+                a suite as defined in suites.json.
+    """
+    prefs = {}
+    for profile in get_profiles(key):
+        prefs.update(read_prefs(profile))
+    return prefs
+
+
+def format_diff(diff, fmt, limit_key):
+    """Format a diff."""
+    indent = '  '
+    if limit_key:
+        diff = {limit_key: diff[limit_key]}
+        indent = ''
+
+    if fmt == 'json':
+        print(json.dumps(diff, sort_keys=True, indent=2))
+        return 0
+
+    lines = []
+    for key, prefs in sorted(diff.items()):
+        if not limit_key:
+            lines.append("{}:".format(key))
+
+        for pref, value in sorted(prefs.items()):
+            context = {'pref': pref, 'value': repr(value)}
+
+            if isinstance(value, list):
+                context['value_a'] = repr(value[0])
+                context['value_b'] = repr(value[1])
+                text = FORMAT_STRINGS[fmt][1].format(**context)
+            else:
+                text = FORMAT_STRINGS[fmt][0].format(**context)
+
+            lines.append('{}{}'.format(indent, text))
+        lines.append('')
+    print('\n'.join(lines).strip())
+
+
+def diff(a, b, fmt, limit_key):
+    """Diff two profiles or suites.
+
+    :param a: The first profile or suite name.
+    :param b: The second profile or suite name.
+    """
+    prefs_a = read(a)
+    prefs_b = read(b)
+    res = jsondiff.diff(prefs_a, prefs_b, syntax='symmetric')
+    if not res:
+        return 0
+
+    if isinstance(res, list) and len(res) == 2:
+        res = {
+            jsondiff.Symbol('delete'): res[0],
+            jsondiff.Symbol('insert'): res[1],
+        }
+
+    # Post process results to make them JSON compatible and a
+    # bit more clear. Also calculate identical prefs.
+    results = {}
+    results['change'] = {k: v for k, v in res.items() if not isinstance(k, jsondiff.Symbol)}
+
+    symbols = [(k, v) for k, v in res.items() if isinstance(k, jsondiff.Symbol)]
+    results['insert'] = {k: v for sym, pref in symbols for k, v in pref.items()
+                         if sym.label == 'insert'}
+    results['delete'] = {k: v for sym, pref in symbols for k, v in pref.items()
+                         if sym.label == 'delete'}
+
+    same = set(prefs_a.keys()) - set(chain(*results.values()))
+    results['same'] = {k: v for k, v in prefs_a.items() if k in same}
+    return format_diff(results, fmt, limit_key)
+
+
+def read_with_comments(path):
+    with open(path, 'r') as fh:
+        lines = fh.readlines()
+
+    result = []
+    buf = []
+    for line in lines:
+        line = line.strip()
+        if not line:
+            continue
+
+        if line.startswith('//'):
+            buf.append(line)
+            continue
+
+        if buf:
+            result.append(buf + [line])
+            buf = []
+            continue
+
+        result.append([line])
+    return result
+
+
+def sort_file(path):
+    """Sort the given pref file alphabetically, preserving preceding comments
+    that start with '//'.
+
+    :param path: Path to the preference file to sort.
+    """
+    result = read_with_comments(path)
+    result = sorted(result, key=lambda x: x[-1])
+    result = chain(*result)
+
+    with open(path, 'w') as fh:
+        fh.write('\n'.join(result) + '\n')
+
+
+def sort(profile):
+    """Sort all prefs in the given profile alphabetically. This will preserve
+    comments on preceding lines.
+
+    :param profile: The name of the profile to sort.
+    """
+    pref_files = Profile.preference_file_names
+
+    for name in pref_files:
+        path = os.path.join(here, profile, name)
+        if os.path.isfile(path):
+            sort_file(path)
+
+
+def show(suite):
+    """Display all prefs set in profiles used by the given suite.
+
+    :param suite: The name of the suite to show preferences for. This must
+                  be a key in suites.json.
+    """
+    for k, v in sorted(read(suite).items()):
+        print("{}: {}".format(k, repr(v)))
+
+
+def rm(profile, pref_file):
+    if pref_file == '-':
+        lines = sys.stdin.readlines()
+    else:
+        with open(pref_file, 'r') as fh:
+            lines = fh.readlines()
+
+    lines = [l.strip() for l in lines if l.strip()]
+    if not lines:
+        return
+
+    def filter_line(content):
+        return not any(line in content[-1] for line in lines)
+
+    path = os.path.join(here, profile, 'user.js')
+    contents = read_with_comments(path)
+    contents = filter(filter_line, contents)
+    contents = chain(*contents)
+    with open(path, 'w') as fh:
+        fh.write('\n'.join(contents))
+
+
+def cli(args=sys.argv[1:]):
+    parser = ArgumentParser()
+    subparsers = parser.add_subparsers(dest='func')
+    subparsers.required = True
+
+    diff_parser = subparsers.add_parser('diff')
+    diff_parser.add_argument('a', metavar='A',
+                             help="Path to the first profile or suite name to diff.")
+    diff_parser.add_argument('b', metavar='B',
+                             help="Path to the second profile or suite name to diff.")
+    diff_parser.add_argument('-f', '--format', dest='fmt', default='pretty',
+                             choices=['pretty', 'json', 'names'],
+                             help="Format to dump diff in (default: pretty)")
+    diff_parser.add_argument('-k', '--limit-key', default=None,
+                             choices=['change', 'delete', 'insert', 'same'],
+                             help="Restrict diff to the specified key.")
+    diff_parser.set_defaults(func=diff)
+
+    sort_parser = subparsers.add_parser('sort')
+    sort_parser.add_argument('profile', help="Path to profile to sort preferences.")
+    sort_parser.set_defaults(func=sort)
+
+    show_parser = subparsers.add_parser('show')
+    show_parser.add_argument('suite', help="Name of suite to show arguments for.")
+    show_parser.set_defaults(func=show)
+
+    rm_parser = subparsers.add_parser('rm')
+    rm_parser.add_argument('profile', help="Name of the profile to remove prefs from.")
+    rm_parser.add_argument('--pref-file', default='-', help="File containing a list of pref "
+                           "substrings to delete (default: stdin)")
+    rm_parser.set_defaults(func=rm)
+
+    args = vars(parser.parse_args(args))
+    func = args.pop('func')
+    func(**args)
+
+
+if __name__ == '__main__':
+    sys.exit(cli())
diff --git a/testing/profiles/profiles.json b/testing/profiles/profiles.json
new file mode 100644
index 0000000000..d52864ded1
--- /dev/null
+++ b/testing/profiles/profiles.json
@@ -0,0 +1,41 @@
+{
+  "geckoview-junit": [
+    "base",
+    "common",
+    "unittest-required",
+    "unittest-features",
+    "geckoview-junit"
+  ],
+  "mochitest": [
+    "base",
+    "common",
+    "unittest-required",
+    "unittest-features",
+    "mochitest"
+  ],
+  "profileserver": [
+    "base",
+    "common",
+    "unittest-required",
+    "unittest-features",
+    "profileserver"
+  ],
+  "raptor": ["base", "common", "perf", "raptor"],
+  "reftest": ["base", "common", "reftest"],
+  "talos": ["base", "common", "perf"],
+  "valgrind": [
+    "base",
+    "common",
+    "unittest-required",
+    "unittest-features",
+    "valgrind"
+  ],
+  "xpcshell": ["base", "xpcshell"],
+  "web-platform-tests": [
+    "base",
+    "common",
+    "unittest-required",
+    "unittest-features",
+    "web-platform"
+  ]
+}
diff --git a/testing/profiles/profileserver/extensions/README.txt b/testing/profiles/profileserver/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/profileserver/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/profileserver/user.js b/testing/profiles/profileserver/user.js
new file mode 100644
index 0000000000..b1a46af982
--- /dev/null
+++ b/testing/profiles/profileserver/user.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/. */
+
+// Preferences file for profileserver.
+/* globals user_pref */
+// Turn off budget throttling for the profile server
+user_pref("dom.timeout.enable_budget_timer_throttling", false);
+// TODO: Bug 1795750 - Re-enable this pref when we have a new version of the
+// Quitter XPI with a simpler version format.
+user_pref("extensions.webextensions.warnings-as-errors", false);
diff --git a/testing/profiles/raptor-android/extensions/README.txt b/testing/profiles/raptor-android/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/raptor-android/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/raptor-android/user.js b/testing/profiles/raptor-android/user.js
new file mode 100644
index 0000000000..62081bfe2d
--- /dev/null
+++ b/testing/profiles/raptor-android/user.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/. */
+
+// Preferences file used by the raptor harness exclusively on android
+/* globals user_pref */
+
+// disk cache smart size is enabled in shipped apps
+user_pref("browser.cache.disk.smart_size.enabled", true);
+
+// Raptor's manifest.json contains the "geckoProfiler" permission, which is
+// not supported on Android. Ignore the warning about the unknown permission.
+user_pref("extensions.webextensions.warnings-as-errors", false);
+// disable telemetry bug 1639148
+user_pref("toolkit.telemetry.server", "");
+user_pref("telemetry.fog.test.localhost_port", -1);
diff --git a/testing/profiles/raptor/extensions/README.txt b/testing/profiles/raptor/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/raptor/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/raptor/user.js b/testing/profiles/raptor/user.js
new file mode 100644
index 0000000000..dcca82e0f9
--- /dev/null
+++ b/testing/profiles/raptor/user.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/. */
+
+// Preferences file used by the raptor harness
+/* globals user_pref */
+// prevents normandy from running updates during the tests
+user_pref("app.normandy.enabled", false);
+
+// Avoid the status panel indicating loading state which messes up
+// screenshots.
+user_pref("browser.tabs.hideStatusPanel", true);
+
+user_pref("dom.performance.time_to_non_blank_paint.enabled", true);
+user_pref("dom.performance.time_to_contentful_paint.enabled", true);
+user_pref("dom.performance.time_to_dom_content_flushed.enabled", true);
+user_pref("dom.performance.time_to_first_interactive.enabled", true);
+
+// required for geckoview logging
+user_pref("geckoview.console.enabled", true);
+
+// get the console logging out of the webext into the stdout
+user_pref("browser.dom.window.dump.enabled", true);
+user_pref("devtools.console.stdout.chrome", true);
+user_pref("devtools.console.stdout.content", true);
+
+// prevent pages from opening after a crash
+user_pref("browser.sessionstore.resume_from_crash", false);
+
+// disable the background hang monitor
+user_pref("toolkit.content-background-hang-monitor.disabled", true);
+
+// disable async stacks to match release builds
+// https://developer.mozilla.org/en-US/docs/Mozilla/Benchmarking#Async_Stacks
+user_pref('javascript.options.asyncstack', false);
+
+// disable Firefox Telemetry (and some other things too)
+// https://bugzilla.mozilla.org/show_bug.cgi?id=1533879
+user_pref('datareporting.healthreport.uploadEnabled', false);
+
+// Telemetry initialization happens on a delay, that may elapse exactly in the
+// middle of some raptor tests. While it doesn't do a lot of expensive work, it
+// causes some I/O and thread creation, that can add noise to performance
+// profiles we use to analyze performance regressions.
+// https://bugzilla.mozilla.org/show_bug.cgi?id=1706180
+user_pref('toolkit.telemetry.initDelay', 99999999);
+
+// disable autoplay for raptor tests
+user_pref('media.autoplay.default', 5);
+user_pref('media.autoplay.ask-permission', true);
+user_pref('media.autoplay.blocking_policy', 1);
+user_pref('media.allowed-to-play.enabled', false);
+user_pref('media.block-autoplay-until-in-foreground', true);
diff --git a/testing/profiles/reftest/extensions/README.txt b/testing/profiles/reftest/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/reftest/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/reftest/user.js b/testing/profiles/reftest/user.js
new file mode 100644
index 0000000000..765d17e6a7
--- /dev/null
+++ b/testing/profiles/reftest/user.js
@@ -0,0 +1,105 @@
+// Preference file for the reftest harness.
+/* globals user_pref */
+// Make sure Shield doesn't hit the network.
+user_pref("app.normandy.api_url", "https://localhost/selfsupport-dummy/");
+user_pref("app.update.staging.enabled", false);
+user_pref("browser.safebrowsing.blockedURIs.enabled", false);
+user_pref("browser.safebrowsing.downloads.enabled", false);
+user_pref("browser.safebrowsing.downloads.remote.url", "http://127.0.0.1/safebrowsing-dummy/gethash");
+user_pref("browser.safebrowsing.malware.enabled", false);
+// Likewise for safebrowsing.
+user_pref("browser.safebrowsing.phishing.enabled", false);
+user_pref("browser.safebrowsing.provider.google.gethashURL", "http://127.0.0.1/safebrowsing-dummyg/gethash");
+user_pref("browser.safebrowsing.provider.google.updateURL", "http://127.0.0.1/safebrowsing-dummyg/update");
+user_pref("browser.safebrowsing.provider.google4.gethashURL", "http://127.0.0.1/safebrowsing-dummyg4/gethash");
+user_pref("browser.safebrowsing.provider.google4.updateURL", "http://127.0.0.1/safebrowsing-dummyg4/update");
+user_pref("browser.safebrowsing.provider.mozilla.gethashURL", "http://127.0.0.1/safebrowsing-dummym/gethash");
+user_pref("browser.safebrowsing.provider.mozilla.updateURL", "http://127.0.0.1/safebrowsing-dummym/update");
+// use about:blank, not browser.startup.homepage
+user_pref("browser.startup.page", 0);
+// Since our tests are 800px wide, set the assume-designed-for width of all
+// pages to be 800px (instead of the default of 980px). This ensures that
+// in our 800px window we don't zoom out by default to try to fit the
+// assumed 980px content.
+user_pref("browser.viewport.desktopWidth", 800);
+user_pref("datareporting.healthreport.uploadEnabled", false);
+// Don't forcibly kill content processes after a timeout
+user_pref("dom.ipc.tabs.shutdownTimeoutSecs", 0);
+// For mochitests, we're more interested in testing the behavior of in-
+// content XBL bindings, so we set this pref to true. In reftests, we're
+// more interested in testing the behavior of XBL as it works in chrome,
+// so we want this pref to be false.
+user_pref("dom.use_xbl_scopes_for_remote_xul", false);
+user_pref("extensions.autoDisableScopes", 0);
+// Disable blocklist updates so we don't have them reported as leaks
+user_pref("extensions.blocklist.enabled", false);
+user_pref("extensions.getAddons.cache.enabled", false);
+user_pref("extensions.getAddons.get.url", "http://localhost/extensions-dummy/repositoryGetURL");
+user_pref("extensions.systemAddon.update.url", "http://localhost/dummy-system-addons.xml");
+user_pref("gfx.color_management.force_srgb", true);
+user_pref("gfx.color_management.mode", 2);
+user_pref("gfx.logging.level", 1);
+// Disable downscale-during-decode, since it makes reftests more difficult.
+user_pref("image.downscale-during-decode.enabled", false);
+// We do the capturing the reftest results with sync decoding
+// so we want to be consistent.
+user_pref("image.decode-sync.enabled", true);
+// Disable interruptible reflow since (1) it's normally not going to
+// happen, but (2) it might happen if we somehow end up with both
+// pending user events and clock skew.  So to avoid having to change
+// MakeProgress to deal with waiting for interruptible reflows to
+// complete for a rare edge case, we just disable interruptible
+// reflow so that that rare edge case doesn't lead to reftest
+// failures.
+user_pref("layout.interruptible-reflow.enabled", false);
+// Disable the fade of overlay scrollbars, since we can't guarantee taking both
+// reftest snapshots at the same point during the fade.
+user_pref("layout.testing.overlay-scrollbars.always-visible", true);
+user_pref("ui.scrollbarFadeDuration", 0);
+// The broken image icon doesn't block the load event and thus there's no easy
+// way to guarantee it's loaded by the time we take the reftest screenshot.
+user_pref("layout.image.eager_broken_image_icon", true);
+user_pref("media.gmp-manager.url.override", "http://localhost/dummy-gmp-manager.xml");
+// Reftests load a lot of URLs very quickly. This puts avoidable and
+// unnecessary I/O pressure on the Places DB (measured to be in the
+// gigabytes).
+user_pref("places.history.enabled", false);
+user_pref("privacy.trackingprotection.annotate_channels", false);
+user_pref("privacy.trackingprotection.enabled", false);
+user_pref("privacy.trackingprotection.pbmode.enabled", false);
+// Disable all recommended Remote Protocol preferences for Gecko tests.
+// The prefs recommended by Remote Protocol are typically geared towards
+// consumer automation; not vendor testing.
+user_pref("remote.prefs.recommended", false);
+// Checking whether two files are the same is slow on Windows.
+// Setting this pref makes tests run much faster there. Reftests also
+// rely on this to load downloadable fonts (which are restricted to same
+// origin policy by default) from outside their directory.
+user_pref("security.fileuri.strict_origin_policy", false);
+user_pref("startup.homepage_override_url", "");
+user_pref("startup.homepage_welcome_url", "");
+user_pref("startup.homepage_welcome_url.additional", "");
+// A fake bool pref for "@supports -moz-bool-pref" sanify test.
+user_pref("testing.supports.moz-bool-pref", false);
+// Ensure that telemetry is disabled, so we don't connect to the telemetry
+// server in the middle of the tests.
+user_pref("toolkit.telemetry.enabled", false);
+user_pref("toolkit.telemetry.server", "https://%(server)s/telemetry-dummy/");
+user_pref("telemetry.fog.test.localhost_port", -1);
+user_pref("ui.caretBlinkTime", -1);
+user_pref("ui.caretWidth", 1);
+user_pref("ui.prefersReducedMotion", 0);
+user_pref("ui.systemUsesDarkTheme", 0);
+user_pref("ui.useAccessibilityTheme", 0);
+user_pref("ui.windowForeground", "");
+user_pref("ui.windowBackground", "");
+// Turn off the Push service.
+user_pref("dom.push.serverURL", "");
+// Disable intermittent telemetry collection
+user_pref("toolkit.telemetry.initDelay", 99999999);
+// Setting this pref to true for usercss reftests, since it relies on userContent.css
+user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true);
+// Use a light color-scheme unless explicitly overriden.
+user_pref("layout.css.prefers-color-scheme.content-override", 1);
+// Force OffscreenCanvas support
+user_pref("gfx.offscreencanvas.enabled", true);
diff --git a/testing/profiles/unittest-features/extensions/README.txt b/testing/profiles/unittest-features/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/unittest-features/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/unittest-features/user.js b/testing/profiles/unittest-features/user.js
new file mode 100644
index 0000000000..f4c349a4b1
--- /dev/null
+++ b/testing/profiles/unittest-features/user.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/. */
+
+// Base preferences file for enabling unittest features.
+// Not enabling these features cause many unittests that
+// expect these prefs to be set to fail.
+// Ideally, tests depending on these prefs should be setting
+// the prefs themselves in their manifests...
+// NOTE: Setting prefs to enable unittests to run at all
+// should occur in unittest-required/user.js, not here!
+/* globals user_pref */
+// Enable w3c touch events for testing
+user_pref("dom.w3c_touch_events.enabled", 1);
+// Enable CSS initial-letter for testing
+user_pref("layout.css.initial-letter.enabled", true);
+// Enable Media Source Extensions for testing
+user_pref("media.mediasource.mp4.enabled", true);
+user_pref("media.mediasource.webm.enabled", true);
+user_pref("media.av1.enabled", true);
+user_pref("media.eme.enabled", true);
+user_pref("dom.forms.datetime.others", true);
+// Enable Gamepad
+user_pref("dom.gamepad.enabled", true);
+user_pref("dom.gamepad.non_standard_events.enabled", true);
+// Enable form autofill feature testing.
+user_pref("extensions.formautofill.addresses.available", "on");
+user_pref("extensions.formautofill.creditCards.available", "on");
diff --git a/testing/profiles/unittest-required/extensions/README.txt b/testing/profiles/unittest-required/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/unittest-required/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/unittest-required/user.js b/testing/profiles/unittest-required/user.js
new file mode 100644
index 0000000000..909a371e64
--- /dev/null
+++ b/testing/profiles/unittest-required/user.js
@@ -0,0 +1,230 @@
+/* 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/. */
+
+// Base preferences file to allow unittests to run successfully.
+// NOTE: Toggling prefs for testing features should happen in
+// unittest-features/user.js or in harness/test manifests, not here!
+/* globals user_pref */
+user_pref("accessibility.typeaheadfind.autostart", false);
+// Make sure Shield doesn't hit the network.
+user_pref("app.normandy.api_url", "");
+// Make sure the notification permission migration test doesn't hit the network.
+user_pref("app.support.baseURL", "http://{server}/support-dummy/");
+user_pref("app.update.staging.enabled", false);
+// Increase the APZ content response timeout in tests to 1 minute.
+// This is to accommodate the fact that test environments tends to be slower
+// than production environments (with the b2g emulator being the slowest of them
+// all), resulting in the production timeout value sometimes being exceeded
+// and causing false-positive test failures. See bug 1176798, bug 1177018,
+// bug 1210465.
+user_pref("apz.content_response_timeout", 60000);
+user_pref("browser.EULA.override", true);
+// Disable Bookmark backups by default.
+user_pref("browser.bookmarks.max_backups", 0);
+user_pref("browser.console.showInPanel", true);
+// Don't connect to Yahoo! for RSS feed tests.
+// en-US only uses .types.0.uri, but set all of them just to be sure.
+user_pref("browser.contentHandlers.types.0.uri", "http://test1.example.org/rss?url=%s");
+user_pref("browser.contentHandlers.types.1.uri", "http://test1.example.org/rss?url=%s");
+user_pref("browser.contentHandlers.types.2.uri", "http://test1.example.org/rss?url=%s");
+user_pref("browser.contentHandlers.types.3.uri", "http://test1.example.org/rss?url=%s");
+user_pref("browser.contentHandlers.types.4.uri", "http://test1.example.org/rss?url=%s");
+user_pref("browser.contentHandlers.types.5.uri", "http://test1.example.org/rss?url=%s");
+// Indicate that the download panel has been shown once so that whichever
+// download test runs first doesn't show the popup inconsistently.
+user_pref("browser.download.panel.shown", true);
+user_pref("browser.newtabpage.activity-stream.default.sites", "");
+user_pref("browser.newtabpage.activity-stream.telemetry", false);
+// Point the url-classifier to the local testing server for fast failures
+user_pref("browser.safebrowsing.downloads.remote.url", "http://{server}/safebrowsing-dummy/update");
+user_pref("browser.safebrowsing.provider.google.gethashURL", "http://{server}/safebrowsing-dummy/gethash");
+user_pref("browser.safebrowsing.provider.google.updateURL", "http://{server}/safebrowsing-dummy/update");
+user_pref("browser.safebrowsing.provider.google4.gethashURL", "http://{server}/safebrowsing4-dummy/gethash");
+user_pref("browser.safebrowsing.provider.google4.updateURL", "http://{server}/safebrowsing4-dummy/update");
+user_pref("browser.safebrowsing.provider.mozilla.gethashURL", "http://{server}/safebrowsing-dummy/gethash");
+user_pref("browser.safebrowsing.provider.mozilla.updateURL", "http://{server}/safebrowsing-dummy/update");
+user_pref("browser.search.suggest.timeout", 10000); // use a 10s suggestion timeout in tests
+user_pref("browser.shell.checkDefaultBrowser", false);
+user_pref("browser.startup.page", 0); // use about:blank, not browser.startup.homepage
+// Don't show a delay when hiding the audio indicator during tests
+user_pref("browser.tabs.delayHidingAudioPlayingIconMS", 0);
+// force tablet UI off
+user_pref("browser.ui.layout.tablet", 0);
+// Ensure UITour won't hit the network
+user_pref("browser.uitour.pinnedTabUrl", "http://{server}/uitour-dummy/pinnedTab");
+user_pref("browser.uitour.url", "http://{server}/uitour-dummy/tour");
+// Turn off Merino suggestions in the location bar so as not to trigger network
+// connections.
+user_pref("browser.urlbar.merino.endpointURL", "");
+user_pref("browser.urlbar.speculativeConnect.enabled", false);
+// Turn off search suggestions in the location bar so as not to trigger network
+// connections.
+user_pref("browser.urlbar.suggest.searches", false);
+// URIFixup whitelist
+user_pref("browser.fixup.domainsuffixwhitelist.test", true);
+user_pref("browser.warnOnQuit", false);
+// Enable webapps testing mode, which bypasses native installation.
+user_pref("browser.webapps.testing", true);
+user_pref("captivedetect.canonicalURL", "http://{server}/captive-detect/success.txt");
+// Enable android logcat for better diagnostics on beta/release
+user_pref("consoleservice.logcat", true);
+// Point Firefox Health Report at a local server. We don't care if it actually
+// works. It just can't hit the default production endpoint.
+user_pref("datareporting.healthreport.documentServerURI", "http://{server}/healthreport/");
+user_pref("datareporting.healthreport.uploadEnabled", false);
+user_pref("devtools.browsertoolbox.panel", "jsdebugger");
+user_pref("devtools.debugger.remote-port", 6023);
+user_pref("devtools.testing", true);
+user_pref("dom.allow_scripts_to_close_windows", true);
+user_pref("dom.disable_open_during_load", false);
+user_pref("dom.ipc.reportProcessHangs", true); // process hang monitor
+// Don't forceably kill content processes after a timeout
+user_pref("dom.ipc.tabs.shutdownTimeoutSecs", 0);
+user_pref("dom.min_background_timeout_value", 1000);
+user_pref("dom.popup_maximum", -1);
+user_pref("dom.block_multiple_popups", false);
+// Prevent connection to the push server for tests.
+user_pref("dom.push.connection.enabled", false);
+user_pref("dom.successive_dialog_time_limit", 0);
+// In the default configuration, we bypass XBL scopes (a security feature) for
+// domains whitelisted for remote XUL, so that intranet apps and such continue
+// to work without major rewrites. However, we also use the whitelist mechanism
+// to run our XBL tests in automation, in which case we really want to be testing
+// the configuration that we ship to users without special whitelisting. So we
+// use an additional pref here to allow automation to use the "normal" behavior.
+user_pref("dom.use_xbl_scopes_for_remote_xul", true);
+user_pref("extensions.autoDisableScopes", 0);
+user_pref("extensions.blocklist.detailsURL", "http://{server}/extensions-dummy/blocklistDetailsURL");
+user_pref("extensions.blocklist.itemURL", "http://{server}/extensions-dummy/blocklistItemURL");
+// XPI extensions are required for test harnesses to load
+user_pref("extensions.defaultProviders.enabled", true);
+// Disable metadata caching for installed add-ons by default
+user_pref("extensions.getAddons.cache.enabled", false);
+// Make sure AddonRepository won't hit the network
+user_pref("extensions.getAddons.get.url", "http://{server}/extensions-dummy/repositoryGetURL");
+user_pref("extensions.getAddons.search.browseURL", "http://{server}/extensions-dummy/repositoryBrowseURL");
+user_pref("extensions.hotfix.url", "http://{server}/extensions-dummy/hotfixURL");
+// Disable intalling any distribution add-ons
+user_pref("extensions.installDistroAddons", false);
+// Disable Screenshots by default for now
+user_pref("extensions.screenshots.disabled", true);
+user_pref("extensions.systemAddon.update.url", "http://{server}/dummy-system-addons.xml");
+user_pref("extensions.systemAddon.update.enabled", false);
+user_pref("extensions.update.background.url", "http://{server}/extensions-dummy/updateBackgroundURL");
+// Point update checks to the local testing server for fast failures
+user_pref("extensions.update.url", "http://{server}/extensions-dummy/updateURL");
+user_pref("findbar.highlightAll", false);
+user_pref("findbar.modalHighlight", false);
+// Existing tests assume there is no font size inflation.
+user_pref("font.size.inflation.emPerLine", 0);
+user_pref("font.size.inflation.minTwips", 0);
+user_pref("general.useragent.updates.url", "https://example.com/0/%APP_ID%");
+// Always use network provider for geolocation tests
+// so we bypass the OSX dialog raised by the corelocation provider
+user_pref("geo.provider.testing", true);
+user_pref("geo.provider.network.logging.enabled", true);
+user_pref("geo.provider.network.scan", false);
+user_pref("geo.provider.network.timeToWaitBeforeSending", 2000);
+user_pref("geo.provider.network.url", "http://{server}/tests/dom/tests/mochitest/geolocation/network_geolocation.sjs");
+user_pref("gfx.color_management.force_srgb", true);
+user_pref("gfx.logging.level", 1);
+// We don't want to hit the real Firefox Accounts server for tests.  We don't
+// actually need a functioning FxA server, so just set it to something that
+// resolves and accepts requests, even if they all fail.
+user_pref("identity.fxaccounts.auth.uri", "https://{server}/fxa-dummy/");
+// Ditto for all the FxA content root URI.
+user_pref("identity.fxaccounts.remote.root", "https://{server}/");
+// Make sure CSS error reporting is enabled for tests
+user_pref("layout.css.report_errors", true);
+user_pref("media.cache_size", 1000);
+user_pref("media.dormant-on-pause-timeout-ms", 0); // Enter dormant immediately without waiting for timeout.
+// Set the number of shmems the PChromiumCDM protocol pre-allocates to 0,
+// so that we test the case where we under-estimate how many shmems we need
+// to send decoded video frames from the CDM to Gecko.
+user_pref("media.eme.chromium-api.video-shmems", 0);
+// Make sure GMPInstallManager won't hit the network.
+user_pref("media.gmp-manager.url.override", "http://{server}/dummy-gmp-manager.xml");
+user_pref("media.hls.server.url", "http://{server}/tests/dom/media/test/hls");
+// Don't block old libavcodec libraries when testing, because our test systems
+// cannot easily be upgraded.
+user_pref("media.libavcodec.allow-obsolete", true);
+user_pref("media.memory_cache_max_size", 32);
+user_pref("media.memory_caches_combined_limit_kb", 256);
+user_pref("media.preload.auto", 3); // auto = enough
+user_pref("media.preload.default", 2); // default = metadata
+user_pref("media.preload.default.cellular", 2); // default = metadata
+user_pref("media.suspend-background-video.enabled", false);
+user_pref("media.test.dumpDebugInfo", true);
+user_pref("media.volume_scale", "0.01");
+// Enable speech synth test service, and disable built in platform services.
+user_pref("media.webspeech.synth.test", true);
+user_pref("network.http.prompt-temp-redirect", false);
+// Disable speculative connections so they aren't reported as leaking when they're hanging around.
+user_pref("network.http.speculative-parallel-limit", 0);
+user_pref("network.manage-offline-status", false);
+// We know the SNTP request will fail, since localhost isn't listening on
+// port 135. The default number of retries (10) is excessive, but retrying
+// at least once will mean that codepath is still tested in automation.
+user_pref("network.sntp.maxRetryCount", 1);
+// Make sure SNTP requests don't hit the network
+user_pref("network.sntp.pools", "{server}");
+// Set places maintenance far in the future (the maximum time possible in an
+// int32_t) to avoid it kicking in during tests. The maintenance can take a
+// relatively long time which may cause unnecessary intermittents and slow down
+// tests. This, like many things, will stop working correctly in 2038.
+user_pref("places.database.lastMaintenance", 2147483647);
+user_pref("privacy.trackingprotection.introURL", "http://{server}/trackingprotection/tour");
+// Disable all recommended Remote Protocol preferences for Gecko tests.
+// The prefs recommended by Remote Protocol are typically geared towards
+// consumer automation; not vendor testing.
+user_pref("remote.prefs.recommended", false);
+user_pref("security.default_personal_cert", "Select Automatically"); // Need to client auth test be w/o any dialogs
+// Existing tests don't wait for the notification button security delay
+user_pref("security.notification_enable_delay", 0);
+// Ensure blocklist updates don't hit the network
+user_pref("services.settings.server", "data:,#remote-settings-dummy/v1");
+user_pref("shell.checkDefaultClient", false);
+// Disable password capture, so that mochitests that include forms aren't
+// influenced by the presence of the persistent doorhanger notification.
+user_pref("signon.rememberSignons", false);
+user_pref("startup.homepage_welcome_url", "about:blank");
+user_pref("startup.homepage_welcome_url.additional", "");
+user_pref("test.mousescroll", true);
+// Don't send 'bhr' ping during tests, otherwise the testing framework might
+// wait on the pingsender to finish and slow down tests.
+user_pref("toolkit.telemetry.bhrPing.enabled", false);
+// Don't send the 'first-shutdown' during tests, otherwise tests expecting
+// main and subsession pings will fail.
+user_pref("toolkit.telemetry.firstShutdownPing.enabled", false);
+// Don't send 'new-profile' ping on new profiles during tests, otherwise the testing framework
+// might wait on the pingsender to finish and slow down tests.
+user_pref("toolkit.telemetry.newProfilePing.enabled", false);
+// We want to collect telemetry, but we don't want to send in the results.
+user_pref("toolkit.telemetry.server", "https://{server}/telemetry-dummy/");
+user_pref("telemetry.fog.test.localhost_port", -1);
+// Don't send the 'shutdown' ping using the pingsender on the first session using
+// the 'pingsender' process. Valgrind marks the process as leaky (e.g. see bug 1364068
+// for the 'new-profile' ping) but does not provide enough information
+// to suppress the leak. Running locally does not reproduce the issue,
+// so disable this until we rewrite the pingsender in Rust (bug 1339035).
+user_pref("toolkit.telemetry.shutdownPingSender.enabledFirstSession", false);
+// A couple of preferences with default values to test that telemetry preference
+// watching is working.
+user_pref("toolkit.telemetry.test.pref1", true);
+user_pref("toolkit.telemetry.test.pref2", false);
+// Disable the caret blinking so we get stable snapshot
+user_pref("ui.caretBlinkTime", -1);
+// Disable scrollbar animations. Tests that count paints / refresh driver ticks
+// shouldn't need to account for them.
+user_pref("ui.scrollbarFadeDuration", 0);
+user_pref("webextensions.tests", true);
+// Disable intermittent telemetry collection
+user_pref("toolkit.telemetry.initDelay", 99999999);
+
+// We use data: to tell the Quitter extension to quit.
+user_pref("security.data_uri.block_toplevel_data_uri_navigations", false);
+
+// We use data: to tell the Quitter extension to quit.
+user_pref("security.data_uri.block_toplevel_data_uri_navigations", false);
+
diff --git a/testing/profiles/valgrind/user.js b/testing/profiles/valgrind/user.js
new file mode 100644
index 0000000000..6db3c1669a
--- /dev/null
+++ b/testing/profiles/valgrind/user.js
@@ -0,0 +1,9 @@
+/* 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/. */
+
+// Preferences file for valgrind.
+/* globals user_pref */
+// TODO: Bug 1795750 - Re-enable this pref when we have a new version of the
+// Quitter XPI with a simpler version format.
+user_pref("extensions.webextensions.warnings-as-errors", false);
diff --git a/testing/profiles/web-platform/extensions/README.txt b/testing/profiles/web-platform/extensions/README.txt
new file mode 100644
index 0000000000..9ec618a6aa
--- /dev/null
+++ b/testing/profiles/web-platform/extensions/README.txt
@@ -0,0 +1,2 @@
+Dropping extensions here will get them installed in all test harnesses
+that make use of this profile.
diff --git a/testing/profiles/web-platform/user.js b/testing/profiles/web-platform/user.js
new file mode 100644
index 0000000000..6370b93645
--- /dev/null
+++ b/testing/profiles/web-platform/user.js
@@ -0,0 +1,98 @@
+/* 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/. */
+
+// Base preferences file for web-platform-tests.
+/* globals user_pref */
+// Don't use the new tab page but about:blank for opened tabs
+user_pref("browser.newtabpage.enabled", false);
+// Don't restore the last open set of tabs if the browser has crashed
+user_pref("browser.sessionstore.resume_from_crash", false);
+//  Disable session restore infobar.
+user_pref("browser.startup.couldRestoreSession.count", -1);
+// Don't show the Bookmarks Toolbar on any tab (the above pref that
+// disables the New Tab Page ends up showing the toolbar on about:blank).
+user_pref("browser.toolbars.bookmarks.visibility", "never");
+// Expose TestUtils interface
+user_pref("dom.testing.testutils.enabled", true);
+// Only install add-ons from the profile and the application scope
+// Also ensure that those are not getting disabled.
+// see: https://developer.mozilla.org/en/Installing_extensions
+user_pref("extensions.autoDisableScopes", 10);
+// Don't open a dialog to show available add-on updates
+user_pref("extensions.update.notifyUser", false);
+// Enable test mode to run multiple tests in parallel
+user_pref("focusmanager.testmode", true);
+// Enable fake media streams for getUserMedia
+user_pref("media.navigator.streams.fake", true);
+// Disable permission prompt for getUserMedia
+user_pref("media.navigator.permission.disabled", true);
+// Enable direct connection
+user_pref("network.proxy.type", 0);
+// Web-platform-tests load a lot of URLs very quickly. This puts avoidable and
+// unnecessary I/O pressure on the Places DB (measured to be in the
+// gigabytes).
+user_pref("places.history.enabled", false);
+// Suppress automatic safe mode after crashes
+user_pref("toolkit.startup.max_resumed_crashes", -1);
+// Run the font loader task eagerly for more predictable behavior
+user_pref("gfx.font_loader.delay", 0);
+// Disable antialiasing for the Ahem font.
+user_pref("gfx.font_rendering.ahem_antialias_none", true);
+// Disable antiphishing popup
+user_pref("network.http.phishy-userpass-length", 255);
+// Disable safebrowsing components
+user_pref("browser.safebrowsing.blockedURIs.enabled", false);
+user_pref("browser.safebrowsing.downloads.enabled", false);
+user_pref("browser.safebrowsing.malware.enabled", false);
+user_pref("browser.safebrowsing.phishing.enabled", false);
+user_pref("browser.safebrowsing.update.enabled", false);
+// Disable high DPI
+user_pref("layout.css.devPixelsPerPx", "1.0");
+// Enable the parallel styling code.
+user_pref("layout.css.stylo-threads", 4);
+// sometime wpt runs test even before the document becomes visible, which would
+// delay video.play() and cause play() running in wrong order.
+user_pref("media.block-autoplay-until-in-foreground", false);
+// Disable dark scrollbars as it can be semi-transparent that many reftests
+// don't expect.
+user_pref("widget.disable-dark-scrollbar", true);
+// Disable scrollbar animations. Otherwise reftests that use overlay scrollbars
+// (only Android right now), might get a snapshot at different times during the
+// animation.
+user_pref("ui.scrollbarFadeDuration", 0);
+// Don't enable paint suppression when the background is unknown. While paint
+// is suppressed, synthetic click events and co. go to the old page, which can
+// be confusing for tests that send click events before the first paint.
+user_pref("nglayout.initialpaint.unsuppress_with_no_background", true);
+user_pref("media.block-autoplay-until-in-foreground", false);
+// Force a light color scheme unless explicitly overridden by pref.
+user_pref("layout.css.prefers-color-scheme.content-override", 1);
+// Force OffscreenCanvas support
+user_pref("gfx.offscreencanvas.enabled", true);
+// A lot of tests use the Reporting API for observing things
+user_pref("dom.reporting.enabled", true);
+// Enable WebDriver BiDi experimental commands and events during tests.
+user_pref("remote.experimental.enabled", true);
+// Disable always partitioning storage with the Storage Access API
+user_pref("privacy.partition.always_partition_third_party_non_cookie_storage", false);
+// Disable OCSP checks in WPT (webtransport triggers these occasionally)
+user_pref("security.OCSP.enabled", 0);
+// Disable download of intermediate certificates.
+user_pref("security.remote_settings.intermediates.enabled", false);
+// Disable prefers-reduced-motion to ensure that smooth scrolls can be tested.
+user_pref("general.smoothScroll", true);
+// Prevent default handlers being added, since these can cause network fetches
+user_pref("gecko.handlerService.defaultHandlersVersion", 100);
+// Enable virtual WebAuthn authenticators.
+user_pref("security.webauth.webauthn_enable_softtoken", true);
+// Disable hardware WebAuthn authenticators.
+user_pref("security.webauth.webauthn_enable_usbtoken", false);
+// Disable the WebAuthn direct attestation consent prompt.
+user_pref("security.webauth.webauthn_testing_allow_direct_attestation", true);
+// Enable WebAuthn conditional mediation.
+user_pref("security.webauthn.enable_conditional_mediation", true);
+// Disable captive portal service
+user_pref("network.captive-portal-service.enabled", false);
+// Enable http2 websockets support
+user_pref("network.http.http2.websockets", true);
diff --git a/testing/profiles/xpcshell/user.js b/testing/profiles/xpcshell/user.js
new file mode 100644
index 0000000000..10a07143c1
--- /dev/null
+++ b/testing/profiles/xpcshell/user.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/. */
+
+// Base preferences file used by the xpcshell harness
+/* globals user_pref */
+/* eslint quotes: 0 */
+user_pref("app.normandy.api_url", "https://%(server)s/selfsupport-dummy/");
+user_pref("browser.safebrowsing.downloads.remote.url", "https://%(server)s/safebrowsing-dummy");
+user_pref("extensions.systemAddon.update.url", "http://%(server)s/dummy-system-addons.xml");
+// Treat WebExtension API/schema warnings as errors.
+user_pref("extensions.webextensions.warnings-as-errors", true);
+// Always use network provider for geolocation tests
+// so we bypass the OSX dialog raised by the corelocation provider
+user_pref("geo.provider.testing", true);
+user_pref("browser.region.network.url", "");
+user_pref("geo.provider.network.compare.url", "");
+user_pref("media.gmp-manager.updateEnabled", false);
+user_pref("media.gmp-manager.url.override", "http://%(server)s/dummy-gmp-manager.xml");
+user_pref("toolkit.telemetry.server", "https://%(server)s/telemetry-dummy");
+user_pref("telemetry.fog.test.localhost_port", -1);
+// Prevent Remote Settings to issue non local connections.
+user_pref("services.settings.server", "data:,#remote-settings-dummy/v1");
+// Prevent intermediate preloads to be downloaded on Remote Settings polling.
+user_pref("security.remote_settings.intermediates.enabled", false);
+// The process priority manager only shifts priorities when it has at least
+// one active tab. xpcshell tabs don't have any active tabs, which would mean
+// all processes would run at low priority, which is not desirable, so we
+// disable the process priority manager entirely here.
+user_pref("dom.ipc.processPriorityManager.enabled", false);
+// Bug 455077 - Ensure we use sRGB as the output profile for test consistency.
+user_pref("gfx.color_management.force_srgb", true);
+user_pref("gfx.color_management.mode", 1);
+// Don't enable remote tiles on new-tab pages in xpcshell
+user_pref("browser.topsites.contile.enabled", false);
+// Don't pull sponsored Top Sites content from the network
+user_pref("browser.newtabpage.activity-stream.showSponsoredTopSites", false);
+user_pref("security.turn_off_all_security_so_that_viruses_can_take_over_this_computer", true);
+user_pref("preferences.force-disable.check.once.policy", true);