gecko-dev/b2g/app/b2g.js

/* 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

pref("toolkit.defaultChromeURI", "chrome://browser/content/shell.xul");
pref("browser.chromeURL", "chrome://browser/content/");

// Device pixel to CSS px ratio, in percent. Set to -1 to calculate based on display density.
pref("browser.viewport.scaleRatio", -1);

/* disable text selection */
pref("browser.ignoreNativeFrameTextSelection", true);

/* cache prefs */
#ifdef MOZ_WIDGET_GONK
pref("browser.cache.disk.enable", true);
pref("browser.cache.disk.capacity", 55000); // kilobytes
pref("browser.cache.disk.parent_directory", "/cache");
#endif
pref("browser.cache.disk.smart_size.enabled", false);
pref("browser.cache.disk.smart_size.first_run", false);

pref("browser.cache.memory.enable", true);
pref("browser.cache.memory.capacity", 1024); // kilobytes

/* image cache prefs */
pref("image.cache.size", 1048576); // bytes
pref("image.high_quality_downscaling.enabled", false);

/* offline cache prefs */
pref("browser.offline-apps.notify", false);
pref("browser.cache.offline.enable", true);
pref("offline-apps.allow_by_default", true);

/* protocol warning prefs */
pref("network.protocol-handler.warn-external.tel", false);
pref("network.protocol-handler.warn-external.mailto", false);
pref("network.protocol-handler.warn-external.vnd.youtube", false);

/* http prefs */
pref("network.http.pipelining", true);
pref("network.http.pipelining.ssl", true);
pref("network.http.proxy.pipelining", true);
pref("network.http.pipelining.maxrequests" , 6);
pref("network.http.keep-alive.timeout", 600);
pref("network.http.max-connections", 20);
pref("network.http.max-persistent-connections-per-server", 6);
pref("network.http.max-persistent-connections-per-proxy", 20);

// See bug 545869 for details on why these are set the way they are
pref("network.buffer.cache.count", 24);
pref("network.buffer.cache.size",  16384);

/* session history */
pref("browser.sessionhistory.max_total_viewers", 1);
pref("browser.sessionhistory.max_entries", 50);

/* session store */
pref("browser.sessionstore.resume_session_once", false);
pref("browser.sessionstore.resume_from_crash", true);
pref("browser.sessionstore.resume_from_crash_timeout", 60); // minutes
pref("browser.sessionstore.interval", 10000); // milliseconds
pref("browser.sessionstore.max_tabs_undo", 1);

/* these should help performance */
pref("mozilla.widget.force-24bpp", true);
pref("mozilla.widget.use-buffer-pixmap", true);
pref("mozilla.widget.disable-native-theme", true);
pref("layout.reflow.synthMouseMove", false);

/* download manager (don't show the window or alert) */
pref("browser.download.useDownloadDir", true);
pref("browser.download.folderList", 1); // Default to ~/Downloads
pref("browser.download.manager.showAlertOnComplete", false);
pref("browser.download.manager.showAlertInterval", 2000);
pref("browser.download.manager.retention", 2);
pref("browser.download.manager.showWhenStarting", false);
pref("browser.download.manager.closeWhenDone", true);
pref("browser.download.manager.openDelay", 0);
pref("browser.download.manager.focusWhenStarting", false);
pref("browser.download.manager.flashCount", 2);
pref("browser.download.manager.displayedHistoryDays", 7);

/* download helper */
pref("browser.helperApps.deleteTempFileOnExit", false);

/* password manager */
pref("signon.rememberSignons", true);
pref("signon.expireMasterPassword", false);
pref("signon.SignonFileName", "signons.txt");

/* autocomplete */
pref("browser.formfill.enable", true);

/* spellcheck */
pref("layout.spellcheckDefault", 0);

/* block popups by default, and notify the user about blocked popups */
pref("dom.disable_open_during_load", true);
pref("privacy.popups.showBrowserMessage", true);

pref("keyword.enabled", true);
pref("keyword.URL", "https://www.google.com/m?ie=UTF-8&oe=UTF-8&sourceid=navclient&gfns=1&q=");

pref("accessibility.typeaheadfind", false);
pref("accessibility.typeaheadfind.timeout", 5000);
pref("accessibility.typeaheadfind.flashBar", 1);
pref("accessibility.typeaheadfind.linksonly", false);
pref("accessibility.typeaheadfind.casesensitive", 0);

// pointer to the default engine name
pref("browser.search.defaultenginename", "chrome://browser/locale/region.properties");

// SSL error page behaviour
pref("browser.ssl_override_behavior", 2);
pref("browser.xul.error_pages.expert_bad_cert", false);

// disable logging for the search service by default
pref("browser.search.log", false);

// disable updating
pref("browser.search.update", false);
pref("browser.search.update.log", false);
pref("browser.search.updateinterval", 6);

// enable search suggestions by default
pref("browser.search.suggest.enabled", true);

// tell the search service that we don't really expose the "current engine"
pref("browser.search.noCurrentEngine", true);

// enable xul error pages
pref("browser.xul.error_pages.enabled", true);

// disable color management
pref("gfx.color_management.mode", 0);

// don't allow JS to move and resize existing windows
pref("dom.disable_window_move_resize", true);

// prevent click image resizing for nsImageDocument
pref("browser.enable_click_image_resizing", false);

// controls which bits of private data to clear. by default we clear them all.
pref("privacy.item.cache", true);
pref("privacy.item.cookies", true);
pref("privacy.item.offlineApps", true);
pref("privacy.item.history", true);
pref("privacy.item.formdata", true);
pref("privacy.item.downloads", true);
pref("privacy.item.passwords", true);
pref("privacy.item.sessions", true);
pref("privacy.item.geolocation", true);
pref("privacy.item.siteSettings", true);
pref("privacy.item.syncAccount", true);

// URL to the Learn More link XXX this is the firefox one.  Bug 495578 fixes this.
pref("browser.geolocation.warning.infoURL", "http://www.mozilla.com/%LOCALE%/firefox/geolocation/");

// base url for the wifi geolocation network provider
pref("geo.wifi.uri", "https://maps.googleapis.com/maps/api/browserlocation/json");

// enable geo
pref("geo.enabled", true);

// content sink control -- controls responsiveness during page load
// see https://bugzilla.mozilla.org/show_bug.cgi?id=481566#c9
pref("content.sink.enable_perf_mode",  2); // 0 - switch, 1 - interactive, 2 - perf
pref("content.sink.pending_event_mode", 0);
pref("content.sink.perf_deflect_count", 1000000);
pref("content.sink.perf_parse_time", 50000000);

// Maximum scripts runtime before showing an alert
pref("dom.max_chrome_script_run_time", 0); // disable slow script dialog for chrome
// Bug 817230 - disable the dialog until we implement its checkbox properly
pref("dom.max_script_run_time", 0);

// plugins
pref("plugin.disable", true);
pref("dom.ipc.plugins.enabled", true);

// product URLs
// The breakpad report server to link to in about:crashes
pref("breakpad.reportURL", "http://crash-stats.mozilla.com/report/index/");
pref("app.releaseNotesURL", "http://www.mozilla.com/%LOCALE%/b2g/%VERSION%/releasenotes/");
pref("app.support.baseURL", "http://support.mozilla.com/b2g");
pref("app.feedbackURL", "http://input.mozilla.com/feedback/");
pref("app.privacyURL", "http://www.mozilla.com/%LOCALE%/m/privacy.html");
pref("app.creditsURL", "http://www.mozilla.org/credits/");
pref("app.featuresURL", "http://www.mozilla.com/%LOCALE%/b2g/features/");
pref("app.faqURL", "http://www.mozilla.com/%LOCALE%/b2g/faq/");

// Name of alternate about: page for certificate errors (when undefined, defaults to about:neterror)
pref("security.alternate_certificate_error_page", "certerror");

pref("security.warn_viewing_mixed", false); // Warning is disabled.  See Bug 616712.

// Override some named colors to avoid inverse OS themes
pref("ui.-moz-dialog", "#efebe7");
pref("ui.-moz-dialogtext", "#101010");
pref("ui.-moz-field", "#fff");
pref("ui.-moz-fieldtext", "#1a1a1a");
pref("ui.-moz-buttonhoverface", "#f3f0ed");
pref("ui.-moz-buttonhovertext", "#101010");
pref("ui.-moz-combobox", "#fff");
pref("ui.-moz-comboboxtext", "#101010");
pref("ui.buttonface", "#ece7e2");
pref("ui.buttonhighlight", "#fff");
pref("ui.buttonshadow", "#aea194");
pref("ui.buttontext", "#101010");
pref("ui.captiontext", "#101010");
pref("ui.graytext", "#b1a598");
pref("ui.highlight", "#fad184");
pref("ui.highlighttext", "#1a1a1a");
pref("ui.infobackground", "#f5f5b5");
pref("ui.infotext", "#000");
pref("ui.menu", "#f7f5f3");
pref("ui.menutext", "#101010");
pref("ui.threeddarkshadow", "#000");
pref("ui.threedface", "#ece7e2");
pref("ui.threedhighlight", "#fff");
pref("ui.threedlightshadow", "#ece7e2");
pref("ui.threedshadow", "#aea194");
pref("ui.window", "#efebe7");
pref("ui.windowtext", "#101010");
pref("ui.windowframe", "#efebe7");

// replace newlines with spaces on paste into single-line text boxes
pref("editor.singleLine.pasteNewlines", 2);

// threshold where a tap becomes a drag, in 1/240" reference pixels
// The names of the preferences are to be in sync with nsEventStateManager.cpp
pref("ui.dragThresholdX", 25);
pref("ui.dragThresholdY", 25);

// Layers Acceleration.  We can only have nice things on gonk, because
// they're not maintained anywhere else.
#ifndef MOZ_WIDGET_GONK
pref("dom.ipc.tabs.disabled", true);
pref("layers.offmainthreadcomposition.enabled", false);
pref("layers.offmainthreadcomposition.animate-opacity", false);
pref("layers.offmainthreadcomposition.animate-transform", false);
pref("layers.offmainthreadcomposition.throttle-animations", false);
pref("layers.async-video.enabled", false);
#else
pref("dom.ipc.tabs.disabled", false);
pref("layers.offmainthreadcomposition.enabled", true);
pref("layers.acceleration.disabled", false);
pref("layers.offmainthreadcomposition.animate-opacity", true);
pref("layers.offmainthreadcomposition.animate-transform", true);
pref("layers.offmainthreadcomposition.throttle-animations", true);
pref("layers.async-video.enabled", true);
pref("layers.async-pan-zoom.enabled", true);
#endif

// Web Notifications
pref("notification.feature.enabled", true);

// IndexedDB
pref("indexedDB.feature.enabled", true);
pref("dom.indexedDB.warningQuota", 5);

// prevent video elements from preloading too much data
pref("media.preload.default", 1); // default to preload none
pref("media.preload.auto", 2);    // preload metadata if preload=auto
pref("media.cache_size", 4096);    // 4MB media cache

// The default number of decoded video frames that are enqueued in
// MediaDecoderReader's mVideoQueue.
pref("media.video-queue.default-size", 3);

//  0: don't show fullscreen keyboard
//  1: always show fullscreen keyboard
// -1: show fullscreen keyboard based on threshold pref
pref("widget.ime.android.landscape_fullscreen", -1);
pref("widget.ime.android.fullscreen_threshold", 250); // in hundreths of inches

// optimize images' memory usage
pref("image.mem.decodeondraw", true);
pref("content.image.allow_locking", true);
pref("image.mem.min_discard_timeout_ms", 10000);
pref("image.mem.max_decoded_image_kb", 5120); /* 5MB */

// enable touch events interfaces
pref("dom.w3c_touch_events.enabled", 1);
pref("dom.w3c_touch_events.safetyX", 0); // escape borders in units of 1/240"
pref("dom.w3c_touch_events.safetyY", 120); // escape borders in units of 1/240"

#ifdef MOZ_SAFE_BROWSING
// Safe browsing does nothing unless this pref is set
pref("browser.safebrowsing.enabled", true);

// Prevent loading of pages identified as malware
pref("browser.safebrowsing.malware.enabled", true);

// Non-enhanced mode (local url lists) URL list to check for updates
pref("browser.safebrowsing.provider.0.updateURL", "http://safebrowsing.clients.google.com/safebrowsing/downloads?client={moz:client}&appver={moz:version}&pver=2.2");

pref("browser.safebrowsing.dataProvider", 0);

// Does the provider name need to be localizable?
pref("browser.safebrowsing.provider.0.name", "Google");
pref("browser.safebrowsing.provider.0.keyURL", "https://sb-ssl.google.com/safebrowsing/newkey?client={moz:client}&appver={moz:version}&pver=2.2");
pref("browser.safebrowsing.provider.0.reportURL", "http://safebrowsing.clients.google.com/safebrowsing/report?");
pref("browser.safebrowsing.provider.0.gethashURL", "http://safebrowsing.clients.google.com/safebrowsing/gethash?client={moz:client}&appver={moz:version}&pver=2.2");

// HTML report pages
pref("browser.safebrowsing.provider.0.reportGenericURL", "http://{moz:locale}.phish-generic.mozilla.com/?hl={moz:locale}");
pref("browser.safebrowsing.provider.0.reportErrorURL", "http://{moz:locale}.phish-error.mozilla.com/?hl={moz:locale}");
pref("browser.safebrowsing.provider.0.reportPhishURL", "http://{moz:locale}.phish-report.mozilla.com/?hl={moz:locale}");
pref("browser.safebrowsing.provider.0.reportMalwareURL", "http://{moz:locale}.malware-report.mozilla.com/?hl={moz:locale}");
pref("browser.safebrowsing.provider.0.reportMalwareErrorURL", "http://{moz:locale}.malware-error.mozilla.com/?hl={moz:locale}");

// FAQ URLs
pref("browser.safebrowsing.warning.infoURL", "http://www.mozilla.com/%LOCALE%/%APP%/phishing-protection/");
pref("browser.geolocation.warning.infoURL", "http://www.mozilla.com/%LOCALE%/%APP%/geolocation/");

// Name of the about: page contributed by safebrowsing to handle display of error
// pages on phishing/malware hits.  (bug 399233)
pref("urlclassifier.alternate_error_page", "blocked");

// The number of random entries to send with a gethash request.
pref("urlclassifier.gethashnoise", 4);

// Randomize all UrlClassifier data with a per-client key.
pref("urlclassifier.randomizeclient", false);

// The list of tables that use the gethash request to confirm partial results.
pref("urlclassifier.gethashtables", "goog-phish-shavar,goog-malware-shavar");

// If an urlclassifier table has not been updated in this number of seconds,
// a gethash request will be forced to check that the result is still in
// the database.
pref("urlclassifier.confirm-age", 2700);

// URL for checking the reason for a malware warning.
pref("browser.safebrowsing.malware.reportURL", "http://safebrowsing.clients.google.com/safebrowsing/diagnostic?client=%NAME%&hl=%LOCALE%&site=");
#endif

// True if this is the first time we are showing about:firstrun
pref("browser.firstrun.show.uidiscovery", true);
pref("browser.firstrun.show.localepicker", true);

// initiated by a user
pref("content.ime.strict_policy", true);

// True if you always want dump() to work
//
// On Android, you also need to do the following for the output
// to show up in logcat:
//
// $ adb shell stop
// $ adb shell setprop log.redirect-stdio true
// $ adb shell start
pref("browser.dom.window.dump.enabled", false);



// Temporarily relax file:// origin checks so that we can use <img>s
// from other dirs as webgl textures and more.  Remove me when we have
// installable apps or wifi support.
pref("security.fileuri.strict_origin_policy", false);

// Default Content Security Policy to apply to privileged and certified apps
pref("security.apps.privileged.CSP.default", "default-src *; script-src 'self'; object-src 'none'; style-src 'self' 'unsafe-inline'");
pref("security.apps.certified.CSP.default", "default-src *; script-src 'self'; object-src 'none'; style-src 'self'");

// Temporarily force-enable GL compositing.  This is default-disabled
// deep within the bowels of the widgetry system.  Remove me when GL
// compositing isn't default disabled in widget/android.
pref("layers.acceleration.force-enabled", true);

// handle links targeting new windows
// 1=current window/tab, 2=new window, 3=new tab in most recent window
pref("browser.link.open_newwindow", 3);

// 0: no restrictions - divert everything
// 1: don't divert window.open at all
// 2: don't divert window.open with features
pref("browser.link.open_newwindow.restriction", 0);

// Enable browser frames (including OOP, except on Windows, where it doesn't
// work), but make in-process browser frames the default.
pref("dom.mozBrowserFramesEnabled", true);

// Enable a (virtually) unlimited number of mozbrowser processes.
// We'll run out of PIDs on UNIX-y systems before we hit this limit.
pref("dom.ipc.processCount", 100000);

pref("dom.ipc.browser_frames.oop_by_default", false);

// Temporary permission hack for WebSMS
pref("dom.sms.enabled", true);
pref("dom.sms.strict7BitEncoding", false); // Disabled by default.

// Temporary permission hack for WebContacts
pref("dom.mozContacts.enabled", true);

// WebAlarms
pref("dom.mozAlarms.enabled", true);

// NetworkStats
#ifdef MOZ_B2G_RIL
pref("dom.mozNetworkStats.enabled", true);
pref("ril.lastKnownMcc", 724);
#endif

// WebSettings
pref("dom.mozSettings.enabled", true);
pref("dom.mozPermissionSettings.enabled", true);

// controls if we want camera support
pref("device.camera.enabled", true);
pref("media.realtime_decoder.enabled", true);

// TCPSocket
pref("dom.mozTCPSocket.enabled", true);

// "Preview" landing of bug 710563, which is bogged down in analysis
// of talos regression.  This is a needed change for higher-framerate
// CSS animations, and incidentally works around an apparent bug in
// our handling of requestAnimationFrame() listeners, which are
// supposed to enable this REPEATING_PRECISE_CAN_SKIP behavior.  The
// secondary bug isn't really worth investigating since it's obseleted
// by bug 710563.
pref("layout.frame_rate.precise", true);

// Handle hardware buttons in the b2g chrome package
pref("b2g.keys.menu.enabled", true);

// Screen timeout in seconds
pref("power.screen.timeout", 60);

pref("full-screen-api.enabled", true);

#ifndef MOZ_WIDGET_GONK
// If we're not actually on physical hardware, don't make the top level widget
// fullscreen when transitioning to fullscreen. This means in emulated
// environments (like the b2g desktop client) we won't make the client window
// fill the whole screen, we'll just make the content fill the client window,
// i.e. it won't give the impression to content that the number of device
// screen pixels changes!
pref("full-screen-api.ignore-widgets", true);
#endif

pref("media.volume.steps", 10);

#ifdef ENABLE_MARIONETTE
//Enable/disable marionette server, set listening port
pref("marionette.defaultPrefs.enabled", true);
pref("marionette.defaultPrefs.port", 2828);
#endif

#ifdef MOZ_UPDATER
// When we're applying updates, we can't let anything hang us on
// quit+restart.  The user has no recourse.
pref("shutdown.watchdog.timeoutSecs", 5);
// Timeout before the update prompt automatically installs the update
pref("b2g.update.apply-prompt-timeout", 60000); // milliseconds
// Amount of time to wait after the user is idle before prompting to apply an update
pref("b2g.update.apply-idle-timeout", 600000); // milliseconds
// Amount of time the updater waits for the process to exit cleanly before
// forcefully exiting the process
pref("b2g.update.self-destruct-timeout", 5000); // milliseconds

pref("app.update.enabled", true);
pref("app.update.auto", false);
pref("app.update.silent", false);
pref("app.update.mode", 0);
pref("app.update.incompatible.mode", 0);
pref("app.update.staging.enabled", true);
pref("app.update.service.enabled", true);

// The URL hosting the update manifest.
pref("app.update.url", "http://update.boot2gecko.org/%CHANNEL%/update.xml");
pref("app.update.channel", "@MOZ_UPDATE_CHANNEL@");

// Interval at which update manifest is fetched.  In units of seconds.
pref("app.update.interval", 86400); // 1 day
// Don't throttle background updates.
pref("app.update.download.backgroundInterval", 0);

// Retry update socket connections every 30 seconds in the cases of certain kinds of errors
pref("app.update.socket.retryTimeout", 30000);

// Max of 20 consecutive retries (total 10 minutes) before giving up and marking
// the update download as failed.
// Note: Offline errors will always retry when the network comes online.
pref("app.update.socket.maxErrors", 20);

// Enable update logging for now, to diagnose growing pains in the
// field.
pref("app.update.log", true);
#else
// Explicitly disable the shutdown watchdog.  It's enabled by default.
// When the updater is disabled, we want to know about shutdown hangs.
pref("shutdown.watchdog.timeoutSecs", -1);
#endif

// Extensions preferences
pref("extensions.update.enabled", false);
pref("extensions.getAddons.cache.enabled", false);

// Context Menu
pref("ui.click_hold_context_menus", true);
pref("ui.click_hold_context_menus.delay", 1000);

// Enable device storage
pref("device.storage.enabled", true);

pref("media.plugins.enabled", false);
pref("media.omx.enabled", true);

// Disable printing (particularly, window.print())
pref("dom.disable_window_print", true);

// Disable window.showModalDialog
pref("dom.disable_window_showModalDialog", true);

// Enable new experimental html forms
pref("dom.experimental_forms", true);

// Turns on gralloc-based direct texturing for Gonk
pref("gfx.gralloc.enabled", false);

// XXXX REMOVE FOR PRODUCTION. Turns on GC and CC logging
pref("javascript.options.mem.log", false);

// Increase mark slice time from 10ms to 30ms
pref("javascript.options.mem.gc_incremental_slice_ms", 30);

pref("javascript.options.mem.gc_high_frequency_heap_growth_max", 120);
pref("javascript.options.mem.gc_high_frequency_heap_growth_min", 101);
pref("javascript.options.mem.gc_high_frequency_high_limit_mb", 40);
pref("javascript.options.mem.gc_high_frequency_low_limit_mb", 10);
pref("javascript.options.mem.gc_low_frequency_heap_growth", 105);
pref("javascript.options.mem.high_water_mark", 6);
pref("javascript.options.mem.gc_allocation_threshold_mb", 3);

// Show/Hide scrollbars when active/inactive
pref("ui.showHideScrollbars", 1);

// Enable the ProcessPriorityManager, and give processes with no visible
// documents a 1s grace period before they're eligible to be marked as
// background.
pref("dom.ipc.processPriorityManager.enabled", true);
pref("dom.ipc.processPriorityManager.gracePeriodMS", 1000);

// Kernel parameters for how processes are killed on low-memory.
pref("gonk.systemMemoryPressureRecoveryPollMS", 5000);
pref("hal.processPriorityManager.gonk.masterOomScoreAdjust", 0);
pref("hal.processPriorityManager.gonk.masterKillUnderMB", 1);
pref("hal.processPriorityManager.gonk.foregroundOomScoreAdjust", 67);
pref("hal.processPriorityManager.gonk.foregroundKillUnderMB", 4);
pref("hal.processPriorityManager.gonk.backgroundOomScoreAdjust", 400);
pref("hal.processPriorityManager.gonk.backgroundKillUnderMB", 8);
pref("hal.processPriorityManager.gonk.notifyLowMemUnderMB", 10);

// Niceness values (i.e., CPU priorities) for B2G processes.
pref("hal.processPriorityManager.gonk.masterNice", -1);
pref("hal.processPriorityManager.gonk.foregroundNice", 0);
pref("hal.processPriorityManager.gonk.backgroundNice", 10);

#ifndef DEBUG
// Enable pre-launching content processes for improved startup time
// (hiding latency).
pref("dom.ipc.processPrelaunch.enabled", true);
// Wait this long before pre-launching a new subprocess.
pref("dom.ipc.processPrelaunch.delayMs", 1000);
#endif

// Ignore the "dialog=1" feature in window.open.
pref("dom.disable_window_open_dialog_feature", true);

// Screen reader support
pref("accessibility.accessfu.activate", 2);

// Enable hit-target fluffing
pref("ui.touch.radius.enabled", false);
pref("ui.touch.radius.leftmm", 3);
pref("ui.touch.radius.topmm", 5);
pref("ui.touch.radius.rightmm", 3);
pref("ui.touch.radius.bottommm", 2);

pref("ui.mouse.radius.enabled", false);
pref("ui.mouse.radius.leftmm", 3);
pref("ui.mouse.radius.topmm", 5);
pref("ui.mouse.radius.rightmm", 3);
pref("ui.mouse.radius.bottommm", 2);

// Disable native prompt
pref("browser.prompt.allowNative", false);

// Minimum delay in milliseconds between network activity notifications (0 means
// no notifications). The delay is the same for both download and upload, though
// they are handled separately. This pref is only read once at startup:
// a restart is required to enable a new value.
pref("network.activity.blipIntervalMilliseconds", 250);

pref("jsloader.reuseGlobal", true);

// Enable font inflation for browser tab content.
pref("font.size.inflation.minTwips", 120);
// And disable it for lingering master-process UI.
pref("font.size.inflation.disabledInMasterProcess", true);

// Enable freeing dirty pages when minimizing memory; this reduces memory
// consumption when applications are sent to the background.
pref("memory.free_dirty_pages", true);

// UAProfile settings
pref("wap.UAProf.url", "");
pref("wap.UAProf.tagname", "x-wap-profile");