This is difference between the default preference of Firefox 58.0 beta 5 and one of 57.0.

Preference difference
PrefFirefox 57.0Firefox 58.0 beta 5
app.update.download.backgroundInterval0undefined
browser.crashReports.unsubmittedCheck.enabledfalsetrue
browser.places.useAsyncTransactionsfalsetrue
browser.preferences.offlineGroup.enabledfalseundefined
browser.safebrowsing.provider.google4.dataSharing.enabledundefinedfalse
browser.safebrowsing.provider.google4.dataSharingURLundefinedhttps://safebrowsing.googleapis.com/v4/threatHits?$ct=application/x-protobuf&key=%GOOGLE_API_KEY%&$httpMethod=POST
browser.schedulePressure.defaultCountundefined3
browser.schedulePressure.enabledundefinedtrue
browser.schedulePressure.timeoutMsundefined1000
browser.sessionstore.max_write_failuresundefined5
browser.tabs.remote.autostartfalsetrue
browser.urlbar.daysBeforeHidingSuggestionsPrompt4undefined
browser.urlbar.lastSuggestionsPromptDate20160601undefined
browser.urlbar.switchTabs.adoptIntoActiveWindowundefinedfalse
browser.xul.error_pages.show_safe_browsing_details_on_loadundefinedfalse
devtools.changesview.enabledundefinedfalse
devtools.debugger.client-source-maps-enabledtrueundefined
devtools.debugger.features.column-breakpointsundefinedfalse
devtools.debugger.features.project-text-searchundefinedtrue
devtools.debugger.features.rootundefinedfalse
devtools.debugger.features.shortcutsundefinedtrue
devtools.debugger.project-directory-rootundefined
devtools.debugger.project-text-search-enabledtrueundefined
devtools.debugger.scopes-visiblefalseundefined
devtools.devedition.promo.enabledfalsetrue
devtools.eventsview.enabledundefinedfalse
devtools.flexboxinspector.enabledundefinedfalse
devtools.fontinspector.enabledtrueundefined
devtools.inspector.mdnDocsTooltip.enabledfalseundefined
devtools.inspector.shapesHighlighter.enabledfalsetrue
devtools.layout.flexbox.openedundefinedtrue
devtools.new-animationinspector.enabledundefinedfalse
devtools.promote.layoutview1undefined
devtools.promote.layoutview.showPromoteBartrueundefined
devtools.responsive.html.enabledtrueundefined
devtools.responsiveUI.no-reload-notificationfalseundefined
dom.abortController.enabledtrueundefined
dom.abortController.fetch.enabledtrueundefined
dom.allow_named_properties_object_for_xrays1undefined
dom.enable_performance_navigation_timingundefinedtrue
dom.ipc.processCount14
dom.ipc.processPrelaunch.enabledfalsetrue
dom.script_loader.bytecode_cache.enabledfalsetrue
dom.timeout.enable_budget_timer_throttlingfalsetrue
dom.vr.display.rafMaxDurationundefined50
editor.use_div_for_default_newlinesfalsetrue
extensions.e10sBlocksEnablingtrueundefined
extensions.e10sMultiBlocksEnablingtrueundefined
extensions.formautofill.availablestaged-rolloutdetect
extensions.formautofill.creditCards.availablefalsetrue
extensions.formautofill.creditCards.usedundefined0
general.smoothScroll.msdPhysics.continuousMotionMaxDeltaMSundefined120
general.smoothScroll.msdPhysics.enabledundefinedfalse
general.smoothScroll.msdPhysics.motionBeginSpringConstantundefined1250
general.smoothScroll.msdPhysics.regularSpringConstantundefined1000
general.smoothScroll.msdPhysics.slowdownMinDeltaMSundefined12
general.smoothScroll.msdPhysics.slowdownMinDeltaRatioundefined1.3
general.smoothScroll.msdPhysics.slowdownSpringConstantundefined2000
geo.provider.use_gpsdfalseundefined
geo.wifi.urihttps://www.googleapis.com/geolocation/v1/geolocate?key=%GOOGLE_API_KEY%https://location.services.mozilla.com/v1/geolocate?key=%MOZILLA_API_KEY%
gfx.webrender.debug.alpha-primitivesundefinedfalse
gfx.webrender.layers-freefalseundefined
gfx.webrendest.enabledfalseundefined
idle_queue.long_period50undefined
idle_queue.min_period3undefined
javascript.options.wasm_baselinejitfalsetrue
layers.advanced.background-color2false
layers.advanced.boxshadow-inset-layers2undefined
layers.advanced.boxshadow-outer-layers2undefined
layers.advanced.button-foreground-layers2undefined
layers.advanced.caret-layers2false
layers.advanced.displaybuttonborder-layers2undefined
layers.advanced.filter-layers2undefined
layers.advanced.solid-color2false
layers.advanced.table2false
layers.omtp.release-capture-on-main-threadundefinedfalse
layout.css.font-display.enabledfalsetrue
layout.css.servo.chrome.enabledundefinedfalse
layout.css.style-attr-with-xml-base.disabledtrueundefined
layout.display-list.dump-parentundefinedfalse
layout.display-list.rebuild-frame-limitundefined500
layout.display-list.retainundefinedfalse
media.omt_data_delivery.enabledundefinedtrue
media.peerconnection.video.vp9_preferredundefinedfalse
media.recorder.audio_node.enabledundefinedfalse
media.recorder.video.frame_dropsundefinedtrue
media.webrtc.debug.aec_log_dirundefined
memory.free_dirty_pagestrueundefined
memory.system_memory_reporterfalseundefined
mousewheel.with_alt.action12
mousewheel.with_shift.action24
network.cookie.thirdparty.nonsecureSessionOnlyundefinedfalse
network.http.tls-handshake-timeoutundefined30
network.standard-url.enable-rustfalseundefined
permissions.default.cameraundefined0
permissions.default.desktop-notificationundefined0
permissions.default.geoundefined0
permissions.default.microphoneundefined0
permissions.default.shortcutsundefined0
security.data_uri.block_toplevel_data_uri_navigationsfalsetrue
security.mixed_content.send_hsts_primingfalsetrue
security.mixed_content.use_hstsfalsetrue
security.onecrl.via.amofalseundefined
security.tls.version.max34
security.use_sqldbfalsetrue
services.sync.engine.bookmarks.validation.enabledundefinedtrue
social.directorieshttps://activations.cdn.mozilla.netundefined
social.remote-install.enabledtrueundefined
social.toast-notifications.enabledtrueundefined
social.whitelisthttps://mozsocial.cliqz.comundefined
Default pref Javascript files
PrefFirefox 57.0Firefox 58.0 beta 5
browser/omni.ja.d/defaults/preferences/debugger.jspresentpresent
browser/omni.ja.d/defaults/preferences/devtools-startup-prefs.jspresentpresent
browser/omni.ja.d/defaults/preferences/devtools.jspresentpresent
browser/omni.ja.d/defaults/preferences/firefox-branding.jspresentpresent
browser/omni.ja.d/defaults/preferences/firefox-l10n.jspresentpresent
browser/omni.ja.d/defaults/preferences/firefox.jspresentpresent
browser/omni.ja.d/defaults/preferences/webide-prefs.jspresentpresent
omni.ja.d/defaults/pref/marionette.jspresentpresent
omni.ja.d/defaults/pref/services-sync.jspresentpresent
omni.ja.d/greprefs.jspresentpresent