feat: introduce puppeteer-firefox (#3628)

This adds a proof-of-concept of `puppeteer-firefox`.
This consists of two parts:
- `//experimental/juggler` - patches to apply to Firefox.
- `//experimental/puppeteer-firefox` - front-end code to
be merged with Puppeteer.

As things become more stable, we'll gradually move it out of
the experimental folder.

experimental/puppeteer-firefox/misc/puppeteer.cfg

@@ -0,0 +1,199 @@
+// Any comment. You must start the file with a comment!
+
+// Make sure Shield doesn't hit the network.
+// pref("app.normandy.api_url", "");
+pref("app.normandy.enabled", false);
+
+// Disable updater
+pref("app.update.enabled", false);
+// make absolutely sure it is really off
+pref("app.update.auto", false);
+pref("app.update.mode", 0);
+pref("app.update.service.enabled", false);
+
+// Dislabe newtabpage
+pref("browser.startup.homepage", 'about:blank');
+pref("browser.newtabpage.enabled", false);
+// Disable topstories
+pref("browser.newtabpage.activity-stream.feeds.section.topstories", 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.
+//
+// (bug 1176798, bug 1177018, bug 1210465)
+pref("apz.content_response_timeout", 60000);
+
+// Indicate that the download panel has been shown once so that
+// whichever download test runs first doesn't show the popup
+// inconsistently.
+pref("browser.download.panel.shown", true);
+
+// Background thumbnails in particular cause grief, and disabling
+// thumbnails in general cannot hurt
+pref("browser.pagethumbnails.capturing_disabled", true);
+
+// Disable safebrowsing components.
+pref("browser.safebrowsing.blockedURIs.enabled", false);
+pref("browser.safebrowsing.downloads.enabled", false);
+pref("browser.safebrowsing.passwords.enabled", false);
+pref("browser.safebrowsing.malware.enabled", false);
+pref("browser.safebrowsing.phishing.enabled", false);
+
+// Disable updates to search engines.
+pref("browser.search.update", false);
+
+// Do not restore the last open set of tabs if the browser has crashed
+pref("browser.sessionstore.resume_from_crash", false);
+
+// Don't check for the default web browser during startup.
+pref("browser.shell.checkDefaultBrowser", false);
+
+// Do not redirect user when a milstone upgrade of Firefox is detected
+pref("browser.startup.homepage_override.mstone", "ignore");
+
+// Disable browser animations (tabs, fullscreen, sliding alerts)
+pref("toolkit.cosmeticAnimations.enabled", false);
+
+// Do not close the window when the last tab gets closed
+pref("browser.tabs.closeWindowWithLastTab", false);
+
+// Do not allow background tabs to be zombified on Android, otherwise for
+// tests that open additional tabs, the test harness tab itself might get
+// unloaded
+pref("browser.tabs.disableBackgroundZombification", false);
+
+// Do not warn when closing all open tabs
+pref("browser.tabs.warnOnClose", false);
+
+// Do not warn when closing all other open tabs
+pref("browser.tabs.warnOnCloseOtherTabs", false);
+
+// Do not warn when multiple tabs will be opened
+pref("browser.tabs.warnOnOpen", false);
+
+// Disable first run splash page on Windows 10
+pref("browser.usedOnWindows10.introURL", "");
+
+// Disable the UI tour.
+//
+// Should be set in profile.
+pref("browser.uitour.enabled", false);
+
+// Turn off search suggestions in the location bar so as not to trigger
+// network connections.
+pref("browser.urlbar.suggest.searches", false);
+
+// Do not warn on quitting Firefox
+pref("browser.warnOnQuit", false);
+
+// Do not show datareporting policy notifications which can
+// interfere with tests
+pref(
+  "datareporting.healthreport.documentServerURI",
+  "http://%(server)s/dummy/healthreport/",
+);
+pref("datareporting.healthreport.logging.consoleEnabled", false);
+pref("datareporting.healthreport.service.enabled", false);
+pref("datareporting.healthreport.service.firstRun", false);
+pref("datareporting.healthreport.uploadEnabled", false);
+pref("datareporting.policy.dataSubmissionEnabled", false);
+pref("datareporting.policy.dataSubmissionPolicyAccepted", false);
+pref("datareporting.policy.dataSubmissionPolicyBypassNotification", true);
+
+// Automatically unload beforeunload alerts
+pref("dom.disable_beforeunload", true);
+
+// Disable popup-blocker
+pref("dom.disable_open_during_load", false);
+
+// Disable the ProcessHangMonitor
+pref("dom.ipc.reportProcessHangs", false);
+
+// Disable slow script dialogues
+pref("dom.max_chrome_script_run_time", 0);
+pref("dom.max_script_run_time", 0);
+
+// Only load extensions from the application and user profile
+// AddonManager.SCOPE_PROFILE + AddonManager.SCOPE_APPLICATION
+pref("extensions.autoDisableScopes", 0);
+pref("extensions.enabledScopes", 5);
+
+// Disable metadata caching for installed add-ons by default
+pref("extensions.getAddons.cache.enabled", false);
+
+// Disable installing any distribution extensions or add-ons.
+pref("extensions.installDistroAddons", false);
+
+// Turn off extension updates so they do not bother tests
+pref("extensions.update.enabled", false);
+pref("extensions.update.notifyUser", false);
+
+// Make sure opening about:addons will not hit the network
+pref(
+  "extensions.webservice.discoverURL",
+  "http://%(server)s/dummy/discoveryURL",
+);
+
+// Allow the application to have focus even it runs in the background
+pref("focusmanager.testmode", true);
+
+// Disable useragent updates
+pref("general.useragent.updates.enabled", false);
+
+// Always use network provider for geolocation tests so we bypass the
+// macOS dialog raised by the corelocation provider
+pref("geo.provider.testing", true);
+
+// Do not scan Wifi
+pref("geo.wifi.scan", false);
+
+// Show chrome errors and warnings in the error console
+pref("javascript.options.showInConsole", true);
+
+// Do not prompt with long usernames or passwords in URLs
+pref("network.http.phishy-userpass-length", 255);
+
+// Do not prompt for temporary redirects
+pref("network.http.prompt-temp-redirect", false);
+
+// Disable speculative connections so they are not reported as leaking
+// when they are hanging around
+pref("network.http.speculative-parallel-limit", 0);
+
+// Do not automatically switch between offline and online
+pref("network.manage-offline-status", false);
+
+// Make sure SNTP requests do not hit the network
+pref("network.sntp.pools", "%(server)s");
+
+// Local documents have access to all other local documents,
+// including directory listings
+pref("security.fileuri.strict_origin_policy", false);
+
+// Tests do not wait for the notification button security delay
+pref("security.notification_enable_delay", 0);
+
+// Ensure blocklist updates do not hit the network
+pref("services.settings.server", "http://%(server)s/dummy/blocklist/");
+
+// Do not automatically fill sign-in forms with known usernames and
+// passwords
+pref("signon.autofillForms", false);
+
+// Disable password capture, so that tests that include forms are not
+// influenced by the presence of the persistent doorhanger notification
+pref("signon.rememberSignons", false);
+
+// Disable first-run welcome page
+pref("startup.homepage_welcome_url", "about:blank");
+pref("startup.homepage_welcome_url.additional", "");
+
+// Prevent starting into safe mode after application crashes
+pref("toolkit.startup.max_resumed_crashes", -1);
+lockPref("toolkit.crashreporter.enabled", false);
+
+// Disable crash reporter.
+Components.classes["@mozilla.org/toolkit/crash-reporter;1"].getService(Components.interfaces.nsICrashReporter).submitReports = false;