diff --git a/.eslintignore b/.eslintignore
index 3f270174b312..8259d4a0b174 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -111,9 +111,6 @@ devtools/client/shared/components/reps/
 
 # Ignore devtools preferences files
 devtools/client/preferences/
-devtools/client/webide/preferences/
-devtools/shared/preferences/
-devtools/startup/preferences/devtools-startup.js
 
 # Ignore devtools generated code
 devtools/shared/css/generated/properties-db.js
diff --git a/.prettierignore b/.prettierignore
index cf1d22586ea2..57a9b5d24cd3 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -15,10 +15,6 @@ browser/branding/nightly/pref/firefox-branding.js
 browser/branding/official/pref/firefox-branding.js
 browser/branding/unofficial/pref/firefox-branding.js
 devtools/client/preferences/debugger.js
-devtools/client/preferences/devtools-client.js
-devtools/client/webide/preferences/webide.js
-devtools/shared/preferences/devtools-shared.js
-devtools/startup/preferences/devtools-startup.js
 extensions/pref/autoconfig/test/unit/autoconfig.js
 mobile/android/app/geckoview-prefs.js
 mobile/android/app/mobile.js
diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index 3052a4bdbd73..d86fd11c0449 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1949,3 +1949,432 @@ pref("privacy.socialtracking.notification.period.min", 172800000);
 pref("privacy.socialtracking.notification.counter", 0);
 // maximum number of popup shown in the profile.
 pref("privacy.socialtracking.notification.max", 2);
+
+// Disable WebIDE and ConnectPage by default (Bug 1539451)
+pref("devtools.webide.enabled", false);
+pref("devtools.connectpage.enabled", false);
+
+// Toolbox preferences
+pref("devtools.toolbox.footer.height", 250);
+pref("devtools.toolbox.sidebar.width", 500);
+pref("devtools.toolbox.host", "bottom");
+pref("devtools.toolbox.previousHost", "right");
+pref("devtools.toolbox.selectedTool", "inspector");
+pref("devtools.toolbox.sideEnabled", true);
+pref("devtools.toolbox.zoomValue", "1");
+pref("devtools.toolbox.splitconsoleEnabled", false);
+pref("devtools.toolbox.splitconsoleHeight", 100);
+pref("devtools.toolbox.tabsOrder", "");
+
+// The fission pref is enabling the "Omniscient Browser Toolbox", which will
+// make it possible to debug anything in Firefox (See Bug 1570639 for more
+// information).
+// ⚠ This is a work in progress. Expect weirdness when the pref is enabled. ⚠
+pref("devtools.browsertoolbox.fission", false);
+
+// Toolbox Button preferences
+pref("devtools.command-button-pick.enabled", true);
+pref("devtools.command-button-frames.enabled", true);
+pref("devtools.command-button-splitconsole.enabled", true);
+pref("devtools.command-button-paintflashing.enabled", false);
+pref("devtools.command-button-scratchpad.enabled", false);
+pref("devtools.command-button-responsive.enabled", true);
+pref("devtools.command-button-screenshot.enabled", false);
+pref("devtools.command-button-rulers.enabled", false);
+pref("devtools.command-button-measure.enabled", false);
+pref("devtools.command-button-noautohide.enabled", false);
+
+// Inspector preferences
+// Enable the Inspector
+pref("devtools.inspector.enabled", true);
+// What was the last active sidebar in the inspector
+pref("devtools.inspector.activeSidebar", "layoutview");
+pref("devtools.inspector.remote", false);
+
+// Enable the 3 pane mode in the inspector
+pref("devtools.inspector.three-pane-enabled", true);
+// Enable the 3 pane mode in the chrome inspector
+pref("devtools.inspector.chrome.three-pane-enabled", false);
+// Collapse pseudo-elements by default in the rule-view
+pref("devtools.inspector.show_pseudo_elements", false);
+// The default size for image preview tooltips in the rule-view/computed-view/markup-view
+pref("devtools.inspector.imagePreviewTooltipSize", 300);
+// Enable user agent style inspection in rule-view
+pref("devtools.inspector.showUserAgentStyles", false);
+// Show all native anonymous content
+pref("devtools.inspector.showAllAnonymousContent", false);
+// Show user agent shadow roots
+pref("devtools.inspector.showUserAgentShadowRoots", false);
+// Enable the new Rules View
+pref("devtools.inspector.new-rulesview.enabled", false);
+
+// Grid highlighter preferences
+pref("devtools.gridinspector.gridOutlineMaxColumns", 50);
+pref("devtools.gridinspector.gridOutlineMaxRows", 50);
+pref("devtools.gridinspector.showGridAreas", false);
+pref("devtools.gridinspector.showGridLineNumbers", false);
+pref("devtools.gridinspector.showInfiniteLines", false);
+// Max number of grid highlighters that can be displayed
+pref("devtools.gridinspector.maxHighlighters", 3);
+
+// Whether or not the box model panel is opened in the layout view
+pref("devtools.layout.boxmodel.opened", true);
+// Whether or not the flexbox panel is opened in the layout view
+pref("devtools.layout.flexbox.opened", true);
+// Whether or not the grid inspector panel is opened in the layout view
+pref("devtools.layout.grid.opened", true);
+
+// Enable hovering Box Model values and jumping to their source CSS rule in the
+// rule-view.
+#if defined(NIGHTLY_BUILD)
+  pref("devtools.layout.boxmodel.highlightProperty", true);
+#else
+  pref("devtools.layout.boxmodel.highlightProperty", false);
+#endif
+
+// By how many times eyedropper will magnify pixels
+pref("devtools.eyedropper.zoom", 6);
+
+// Enable to collapse attributes that are too long.
+pref("devtools.markup.collapseAttributes", true);
+// Length to collapse attributes
+pref("devtools.markup.collapseAttributeLength", 120);
+// Whether to auto-beautify the HTML on copy.
+pref("devtools.markup.beautifyOnCopy", false);
+// Whether or not the DOM mutation breakpoints context menu are enabled in the
+// markup view.
+pref("devtools.markup.mutationBreakpoints.enabled", false);
+
+// DevTools default color unit
+pref("devtools.defaultColorUnit", "authored");
+
+// Enable the Memory tools
+pref("devtools.memory.enabled", true);
+
+pref("devtools.memory.custom-census-displays", "{}");
+pref("devtools.memory.custom-label-displays", "{}");
+pref("devtools.memory.custom-tree-map-displays", "{}");
+
+pref("devtools.memory.max-individuals", 1000);
+pref("devtools.memory.max-retaining-paths", 10);
+
+// Enable the Performance tools
+pref("devtools.performance.enabled", true);
+
+// The default Performance UI settings
+pref("devtools.performance.memory.sample-probability", "0.05");
+// Can't go higher than this without causing internal allocation overflows while
+// serializing the allocations data over the RDP.
+pref("devtools.performance.memory.max-log-length", 125000);
+pref("devtools.performance.timeline.hidden-markers",
+  "[\"Composite\",\"CompositeForwardTransaction\"]");
+pref("devtools.performance.profiler.buffer-size", 10000000);
+pref("devtools.performance.profiler.sample-frequency-hz", 1000);
+pref("devtools.performance.ui.invert-call-tree", true);
+pref("devtools.performance.ui.invert-flame-graph", false);
+pref("devtools.performance.ui.flatten-tree-recursion", true);
+pref("devtools.performance.ui.show-platform-data", false);
+pref("devtools.performance.ui.show-idle-blocks", true);
+pref("devtools.performance.ui.enable-memory", false);
+pref("devtools.performance.ui.enable-allocations", false);
+pref("devtools.performance.ui.enable-framerate", true);
+pref("devtools.performance.ui.show-jit-optimizations", false);
+pref("devtools.performance.ui.show-triggers-for-gc-types",
+  "TOO_MUCH_MALLOC ALLOC_TRIGGER LAST_DITCH EAGER_ALLOC_TRIGGER");
+
+// Temporary pref disabling memory flame views
+// TODO remove once we have flame charts via bug 1148663
+pref("devtools.performance.ui.enable-memory-flame", false);
+
+// Enable experimental options in the UI only in Nightly
+#if defined(NIGHTLY_BUILD)
+  pref("devtools.performance.ui.experimental", true);
+#else
+  pref("devtools.performance.ui.experimental", false);
+#endif
+
+// Preferences for the new performance panel. This pref configures the base URL
+// for the profiler.firefox.com instance to use. This is useful so that a
+// developer can change it while working on profiler.firefox.com, or in tests.
+// This isn't exposed directly to the user.
+pref("devtools.performance.recording.ui-base-url", "https://profiler.firefox.com");
+
+// A JSON array of strings, where each string is a file path to an objdir on
+// the host machine. This is used in order to look up symbol information from
+// build artifacts of local builds.
+pref("devtools.performance.recording.objdirs", "[]");
+
+// The default cache UI setting
+pref("devtools.cache.disabled", false);
+
+// The default service workers UI setting
+pref("devtools.serviceWorkers.testing.enabled", false);
+
+// Enable the Network Monitor
+pref("devtools.netmonitor.enabled", true);
+
+// Enable Network Search
+pref("devtools.netmonitor.features.search", false);
+
+// Enable the Application panel
+pref("devtools.application.enabled", false);
+
+// The default Network Monitor UI settings
+pref("devtools.netmonitor.panes-network-details-width", 550);
+pref("devtools.netmonitor.panes-network-details-height", 450);
+pref("devtools.netmonitor.panes-search-width", 550);
+pref("devtools.netmonitor.panes-search-height", 450);
+pref("devtools.netmonitor.filters", "[\"all\"]");
+pref("devtools.netmonitor.visibleColumns",
+  "[\"status\",\"method\",\"domain\",\"file\",\"cause\",\"type\",\"transferred\",\"contentSize\",\"waterfall\"]"
+);
+pref("devtools.netmonitor.columnsData",
+  '[{"name":"status","minWidth":30,"width":5}, {"name":"method","minWidth":30,"width":5}, {"name":"domain","minWidth":30,"width":10}, {"name":"file","minWidth":30,"width":25}, {"name":"url","minWidth":30,"width":25}, {"name":"cause","minWidth":30,"width":10},{"name":"type","minWidth":30,"width":5},{"name":"transferred","minWidth":30,"width":10},{"name":"contentSize","minWidth":30,"width":5},{"name":"waterfall","minWidth":150,"width":25}]');
+pref("devtools.netmonitor.ws.payload-preview-height", 128);
+pref("devtools.netmonitor.ws.visibleColumns",
+  '["data", "time"]'
+);
+pref("devtools.netmonitor.ws.displayed-frames.limit", 500);
+
+pref("devtools.netmonitor.response.ui.limit", 10240);
+
+// Save request/response bodies yes/no.
+pref("devtools.netmonitor.saveRequestAndResponseBodies", true);
+
+// The default Network monitor HAR export setting
+pref("devtools.netmonitor.har.defaultLogDir", "");
+pref("devtools.netmonitor.har.defaultFileName", "%hostname_Archive [%date]");
+pref("devtools.netmonitor.har.jsonp", false);
+pref("devtools.netmonitor.har.jsonpCallback", "");
+pref("devtools.netmonitor.har.includeResponseBodies", true);
+pref("devtools.netmonitor.har.compress", false);
+pref("devtools.netmonitor.har.forceExport", false);
+pref("devtools.netmonitor.har.pageLoadedTimeout", 1500);
+pref("devtools.netmonitor.har.enableAutoExportToFile", false);
+
+// Enable WebSocket monitoring in Nightly builds.
+#if defined(NIGHTLY_BUILD)
+  pref("devtools.netmonitor.features.webSockets", true);
+#else
+  pref("devtools.netmonitor.features.webSockets", false);
+#endif
+
+// Scratchpad settings
+// - recentFileMax: The maximum number of recently-opened files
+//                  stored. Setting this preference to 0 will not
+//                  clear any recent files, but rather hide the
+//                  'Open Recent'-menu.
+// - lineNumbers: Whether to show line numbers or not.
+// - wrapText: Whether to wrap text or not.
+// - showTrailingSpace: Whether to highlight trailing space or not.
+// - editorFontSize: Editor font size configuration.
+// - enableAutocompletion: Whether to enable JavaScript autocompletion.
+pref("devtools.scratchpad.recentFilesMax", 10);
+pref("devtools.scratchpad.lineNumbers", true);
+pref("devtools.scratchpad.wrapText", false);
+pref("devtools.scratchpad.showTrailingSpace", false);
+pref("devtools.scratchpad.editorFontSize", 12);
+pref("devtools.scratchpad.enableAutocompletion", true);
+
+// Enable the Storage Inspector
+pref("devtools.storage.enabled", true);
+
+// Enable the Style Editor.
+pref("devtools.styleeditor.enabled", true);
+pref("devtools.styleeditor.autocompletion-enabled", true);
+pref("devtools.styleeditor.showMediaSidebar", true);
+pref("devtools.styleeditor.mediaSidebarWidth", 238);
+pref("devtools.styleeditor.navSidebarWidth", 245);
+pref("devtools.styleeditor.transitions", true);
+
+// Screenshot Option Settings.
+pref("devtools.screenshot.clipboard.enabled", false);
+pref("devtools.screenshot.audio.enabled", true);
+
+// Enable Scratchpad
+pref("devtools.scratchpad.enabled", false);
+
+// Make sure the DOM panel is hidden by default
+pref("devtools.dom.enabled", false);
+
+// Enable the Accessibility panel.
+pref("devtools.accessibility.enabled", true);
+
+// Web console filters
+pref("devtools.webconsole.filter.error", true);
+pref("devtools.webconsole.filter.warn", true);
+pref("devtools.webconsole.filter.info", true);
+pref("devtools.webconsole.filter.log", true);
+pref("devtools.webconsole.filter.debug", true);
+pref("devtools.webconsole.filter.css", false);
+pref("devtools.webconsole.filter.net", false);
+pref("devtools.webconsole.filter.netxhr", false);
+
+// Webconsole autocomplete preference
+pref("devtools.webconsole.input.autocomplete",true);
+
+// Browser console filters
+pref("devtools.browserconsole.filter.error", true);
+pref("devtools.browserconsole.filter.warn", true);
+pref("devtools.browserconsole.filter.info", true);
+pref("devtools.browserconsole.filter.log", true);
+pref("devtools.browserconsole.filter.debug", true);
+pref("devtools.browserconsole.filter.css", false);
+pref("devtools.browserconsole.filter.net", false);
+pref("devtools.browserconsole.filter.netxhr", false);
+
+// Max number of inputs to store in web console history.
+pref("devtools.webconsole.inputHistoryCount", 300);
+
+// Persistent logging: |true| if you want the relevant tool to keep all of the
+// logged messages after reloading the page, |false| if you want the output to
+// be cleared each time page navigation happens.
+pref("devtools.webconsole.persistlog", false);
+pref("devtools.netmonitor.persistlog", false);
+
+// Web Console timestamp: |true| if you want the logs and instructions
+// in the Web Console to display a timestamp, or |false| to not display
+// any timestamps.
+pref("devtools.webconsole.timestampMessages", false);
+
+// Enable the webconsole sidebar toggle in Nightly builds.
+#if defined(NIGHTLY_BUILD)
+  pref("devtools.webconsole.sidebarToggle", true);
+#else
+  pref("devtools.webconsole.sidebarToggle", false);
+#endif
+
+// Enable editor mode in the console in Nightly builds.
+#if defined(NIGHTLY_BUILD)
+  pref("devtools.webconsole.features.editor", true);
+#else
+  pref("devtools.webconsole.features.editor", false);
+#endif
+
+// Saved editor mode state in the console.
+pref("devtools.webconsole.input.editor", false);
+
+// Editor width for webconsole and browserconsole
+pref("devtools.webconsole.input.editorWidth", 0);
+pref("devtools.browserconsole.input.editorWidth", 0);
+
+// Disable the new performance recording panel by default
+pref("devtools.performance.new-panel-enabled", false);
+
+// Enable message grouping in the console, true by default
+pref("devtools.webconsole.groupWarningMessages", true);
+
+// Saved state of the Display content messages checkbox in the browser console.
+pref("devtools.browserconsole.contentMessages", false);
+
+// Enable client-side mapping service for source maps
+pref("devtools.source-map.client-service.enabled", true);
+
+// The number of lines that are displayed in the web console.
+pref("devtools.hud.loglimit", 10000);
+
+// The developer tools editor configuration:
+// - tabsize: how many spaces to use when a Tab character is displayed.
+// - expandtab: expand Tab characters to spaces.
+// - keymap: which keymap to use (can be 'default', 'emacs' or 'vim')
+// - autoclosebrackets: whether to permit automatic bracket/quote closing.
+// - detectindentation: whether to detect the indentation from the file
+// - enableCodeFolding: Whether to enable code folding or not.
+pref("devtools.editor.tabsize", 2);
+pref("devtools.editor.expandtab", true);
+pref("devtools.editor.keymap", "default");
+pref("devtools.editor.autoclosebrackets", true);
+pref("devtools.editor.detectindentation", true);
+pref("devtools.editor.enableCodeFolding", true);
+pref("devtools.editor.autocomplete", true);
+
+// The angle of the viewport.
+pref("devtools.responsive.viewport.angle", 0);
+// The width of the viewport.
+pref("devtools.responsive.viewport.width", 320);
+// The height of the viewport.
+pref("devtools.responsive.viewport.height", 480);
+// The pixel ratio of the viewport.
+pref("devtools.responsive.viewport.pixelRatio", 0);
+// Whether or not the viewports are left aligned.
+pref("devtools.responsive.leftAlignViewport.enabled", false);
+// Whether to reload when touch simulation is toggled
+pref("devtools.responsive.reloadConditions.touchSimulation", false);
+// Whether to reload when user agent is changed
+pref("devtools.responsive.reloadConditions.userAgent", false);
+// Whether to show the notification about reloading to apply emulation
+pref("devtools.responsive.reloadNotification.enabled", true);
+// Whether or not touch simulation is enabled.
+pref("devtools.responsive.touchSimulation.enabled", false);
+// Whether or not meta viewport is enabled, if and only if touchSimulation
+// is also enabled.
+pref("devtools.responsive.metaViewport.enabled", false);
+// The user agent of the viewport.
+pref("devtools.responsive.userAgent", "");
+
+// Whether to show the settings onboarding tooltip only in release or beta
+// builds.
+#if defined(RELEASE_OR_BETA)
+  pref("devtools.responsive.show-setting-tooltip", true);
+#else
+  pref("devtools.responsive.show-setting-tooltip", false);
+#endif
+// Show the custom user agent input in Nightly builds.
+#if defined(NIGHTLY_BUILD)
+  pref("devtools.responsive.showUserAgentInput", true);
+#else
+  pref("devtools.responsive.showUserAgentInput", false);
+#endif
+
+// Show tab debug targets for This Firefox (on by default for local builds).
+#ifdef MOZILLA_OFFICIAL
+  pref("devtools.aboutdebugging.local-tab-debugging", false);
+#else
+  pref("devtools.aboutdebugging.local-tab-debugging", true);
+#endif
+
+// Show process debug targets.
+pref("devtools.aboutdebugging.process-debugging", true);
+// Stringified array of network locations that users can connect to.
+pref("devtools.aboutdebugging.network-locations", "[]");
+// Debug target pane collapse/expand settings.
+pref("devtools.aboutdebugging.collapsibilities.installedExtension", false);
+pref("devtools.aboutdebugging.collapsibilities.otherWorker", false);
+pref("devtools.aboutdebugging.collapsibilities.serviceWorker", false);
+pref("devtools.aboutdebugging.collapsibilities.sharedWorker", false);
+pref("devtools.aboutdebugging.collapsibilities.tab", false);
+pref("devtools.aboutdebugging.collapsibilities.temporaryExtension", false);
+
+// about:debugging: only show system and hidden extensions in local builds by
+// default.
+#ifdef MOZILLA_OFFICIAL
+  pref("devtools.aboutdebugging.showHiddenAddons", false);
+#else
+  pref("devtools.aboutdebugging.showHiddenAddons", true);
+#endif
+
+// Map top-level await expressions in the console
+pref("devtools.debugger.features.map-await-expression", true);
+
+// Disable autohide for DevTools popups and tooltips.
+// This is currently not exposed by any UI to avoid making
+// about:devtools-toolbox tabs unusable by mistake.
+pref("devtools.popup.disable_autohide", false);
+
+// Load the DevTools toolbox in a frame with type=content instead of type=chrome
+// See Bug 1539979 for more details.
+// We keep the option of running devtools in a chrome frame while we fix racy
+// tests that started failing when using type=content, but this ultimately
+// should be removed.
+pref("devtools.toolbox.content-frame", true);
+
+pref("devtools.webide.templatesURL", "https://code.cdn.mozilla.net/templates/list.json");
+pref("devtools.webide.autoinstallADBExtension", true);
+pref("devtools.webide.autoConnectRuntime", true);
+pref("devtools.webide.restoreLastProject", true);
+pref("devtools.webide.enableLocalRuntime", false);
+pref("devtools.webide.lastConnectedRuntime", "");
+pref("devtools.webide.lastSelectedProject", "");
+pref("devtools.webide.zoom", "1");
+pref("devtools.webide.busyTimeout", 10000);
+
diff --git a/browser/installer/package-manifest.in b/browser/installer/package-manifest.in
index 416cfdadf52e..387010bdbba5 100644
--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -261,17 +261,14 @@
 ; [Webide Files]
 @RESPATH@/browser/chrome/webide@JAREXT@
 @RESPATH@/browser/chrome/webide.manifest
-@RESPATH@/browser/@PREF_DIR@/webide.js
 
 ; [DevTools Startup Files]
 @RESPATH@/browser/chrome/devtools-startup@JAREXT@
 @RESPATH@/browser/chrome/devtools-startup.manifest
-@RESPATH@/browser/@PREF_DIR@/devtools-startup.js
 
 ; DevTools
 @RESPATH@/browser/chrome/devtools@JAREXT@
 @RESPATH@/browser/chrome/devtools.manifest
-@RESPATH@/browser/@PREF_DIR@/devtools-client.js
 @RESPATH@/browser/@PREF_DIR@/debugger.js
 
 ; shell icons
diff --git a/devtools/client/preferences/debugger.js b/devtools/client/preferences/debugger.js
index 0045c564c3b1..8e96cdc43b97 100644
--- a/devtools/client/preferences/debugger.js
+++ b/devtools/client/preferences/debugger.js
@@ -2,6 +2,11 @@
  * 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/>. */
 
+// Most devtools prefs are found in browser/app/profile/firefox.js. The
+// debugger prefs are separate so they can be easily mirrored to the debugger
+// project on GitHub, here:
+// https://github.com/firefox-devtools/debugger/blob/master/assets/panel/prefs.js
+
 // Enable the Debugger
 pref("devtools.debugger.enabled", true);
 pref("devtools.debugger.chrome-debugging-host", "localhost");
diff --git a/devtools/client/preferences/devtools-client.js b/devtools/client/preferences/devtools-client.js
deleted file mode 100644
index cb0f0fb71140..000000000000
--- a/devtools/client/preferences/devtools-client.js
+++ /dev/null
@@ -1,417 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-// Disable WebIDE and ConnectPage by default (Bug 1539451)
-pref("devtools.webide.enabled", false);
-pref("devtools.connectpage.enabled", false);
-
-// Toolbox preferences
-pref("devtools.toolbox.footer.height", 250);
-pref("devtools.toolbox.sidebar.width", 500);
-pref("devtools.toolbox.host", "bottom");
-pref("devtools.toolbox.previousHost", "right");
-pref("devtools.toolbox.selectedTool", "inspector");
-pref("devtools.toolbox.sideEnabled", true);
-pref("devtools.toolbox.zoomValue", "1");
-pref("devtools.toolbox.splitconsoleEnabled", false);
-pref("devtools.toolbox.splitconsoleHeight", 100);
-pref("devtools.toolbox.tabsOrder", "");
-
-// The fission pref is enabling the "Omniscient Browser Toolbox", which will make it
-// possible to debug anything in Firefox (See Bug 1570639 for more information).
-// ⚠ This is a work in progress. Expect weirdness when the pref is flipped on ⚠
-pref("devtools.browsertoolbox.fission", false);
-
-// Toolbox Button preferences
-pref("devtools.command-button-pick.enabled", true);
-pref("devtools.command-button-frames.enabled", true);
-pref("devtools.command-button-splitconsole.enabled", true);
-pref("devtools.command-button-paintflashing.enabled", false);
-pref("devtools.command-button-scratchpad.enabled", false);
-pref("devtools.command-button-responsive.enabled", true);
-pref("devtools.command-button-screenshot.enabled", false);
-pref("devtools.command-button-rulers.enabled", false);
-pref("devtools.command-button-measure.enabled", false);
-pref("devtools.command-button-noautohide.enabled", false);
-
-// Inspector preferences
-// Enable the Inspector
-pref("devtools.inspector.enabled", true);
-// What was the last active sidebar in the inspector
-pref("devtools.inspector.activeSidebar", "layoutview");
-pref("devtools.inspector.remote", false);
-
-// Enable the 3 pane mode in the inspector
-pref("devtools.inspector.three-pane-enabled", true);
-// Enable the 3 pane mode in the chrome inspector
-pref("devtools.inspector.chrome.three-pane-enabled", false);
-// Collapse pseudo-elements by default in the rule-view
-pref("devtools.inspector.show_pseudo_elements", false);
-// The default size for image preview tooltips in the rule-view/computed-view/markup-view
-pref("devtools.inspector.imagePreviewTooltipSize", 300);
-// Enable user agent style inspection in rule-view
-pref("devtools.inspector.showUserAgentStyles", false);
-// Show all native anonymous content
-pref("devtools.inspector.showAllAnonymousContent", false);
-// Show user agent shadow roots
-pref("devtools.inspector.showUserAgentShadowRoots", false);
-// Enable the new Rules View
-pref("devtools.inspector.new-rulesview.enabled", false);
-
-// Grid highlighter preferences
-pref("devtools.gridinspector.gridOutlineMaxColumns", 50);
-pref("devtools.gridinspector.gridOutlineMaxRows", 50);
-pref("devtools.gridinspector.showGridAreas", false);
-pref("devtools.gridinspector.showGridLineNumbers", false);
-pref("devtools.gridinspector.showInfiniteLines", false);
-// Max number of grid highlighters that can be displayed
-pref("devtools.gridinspector.maxHighlighters", 3);
-
-// Whether or not the box model panel is opened in the layout view
-pref("devtools.layout.boxmodel.opened", true);
-// Whether or not the flexbox panel is opened in the layout view
-pref("devtools.layout.flexbox.opened", true);
-// Whether or not the grid inspector panel is opened in the layout view
-pref("devtools.layout.grid.opened", true);
-
-// Enable hovering Box Model values and jumping to their source CSS rule in the rule-view
-#if defined(NIGHTLY_BUILD)
-pref("devtools.layout.boxmodel.highlightProperty", true);
-#else
-pref("devtools.layout.boxmodel.highlightProperty", false);
-#endif
-
-// By how many times eyedropper will magnify pixels
-pref("devtools.eyedropper.zoom", 6);
-
-// Enable to collapse attributes that are too long.
-pref("devtools.markup.collapseAttributes", true);
-// Length to collapse attributes
-pref("devtools.markup.collapseAttributeLength", 120);
-// Whether to auto-beautify the HTML on copy.
-pref("devtools.markup.beautifyOnCopy", false);
-// Whether or not the DOM mutation breakpoints context menu are enabled in the markup view
-pref("devtools.markup.mutationBreakpoints.enabled", false);
-
-// DevTools default color unit
-pref("devtools.defaultColorUnit", "authored");
-
-// Enable the Memory tools
-pref("devtools.memory.enabled", true);
-
-pref("devtools.memory.custom-census-displays", "{}");
-pref("devtools.memory.custom-label-displays", "{}");
-pref("devtools.memory.custom-tree-map-displays", "{}");
-
-pref("devtools.memory.max-individuals", 1000);
-pref("devtools.memory.max-retaining-paths", 10);
-
-// Enable the Performance tools
-pref("devtools.performance.enabled", true);
-
-// The default Performance UI settings
-pref("devtools.performance.memory.sample-probability", "0.05");
-// Can't go higher than this without causing internal allocation overflows while
-// serializing the allocations data over the RDP.
-pref("devtools.performance.memory.max-log-length", 125000);
-pref("devtools.performance.timeline.hidden-markers",
-  "[\"Composite\",\"CompositeForwardTransaction\"]");
-pref("devtools.performance.profiler.buffer-size", 10000000);
-pref("devtools.performance.profiler.sample-frequency-hz", 1000);
-pref("devtools.performance.ui.invert-call-tree", true);
-pref("devtools.performance.ui.invert-flame-graph", false);
-pref("devtools.performance.ui.flatten-tree-recursion", true);
-pref("devtools.performance.ui.show-platform-data", false);
-pref("devtools.performance.ui.show-idle-blocks", true);
-pref("devtools.performance.ui.enable-memory", false);
-pref("devtools.performance.ui.enable-allocations", false);
-pref("devtools.performance.ui.enable-framerate", true);
-pref("devtools.performance.ui.show-jit-optimizations", false);
-pref("devtools.performance.ui.show-triggers-for-gc-types",
-  "TOO_MUCH_MALLOC ALLOC_TRIGGER LAST_DITCH EAGER_ALLOC_TRIGGER");
-
-// Temporary pref disabling memory flame views
-// TODO remove once we have flame charts via bug 1148663
-pref("devtools.performance.ui.enable-memory-flame", false);
-
-// Enable experimental options in the UI only in Nightly
-#if defined(NIGHTLY_BUILD)
-pref("devtools.performance.ui.experimental", true);
-#else
-pref("devtools.performance.ui.experimental", false);
-#endif
-
-// Preferences for the new performance panel
-// This pref configures the base URL for the profiler.firefox.com instance to use. This is
-// useful so that a developer can change it while working on profiler.firefox.com, or in
-// tests.
-// This isn't exposed directly to the user.
-pref("devtools.performance.recording.ui-base-url", "https://profiler.firefox.com");
-
-// A JSON array of strings, where each string is a file path to an objdir on
-// the host machine. This is used in order to look up symbol information from
-// build artifacts of local builds.
-pref("devtools.performance.recording.objdirs", "[]");
-
-// The default cache UI setting
-pref("devtools.cache.disabled", false);
-
-// The default service workers UI setting
-pref("devtools.serviceWorkers.testing.enabled", false);
-
-// Enable the Network Monitor
-pref("devtools.netmonitor.enabled", true);
-
-// Enable Network Search
-pref("devtools.netmonitor.features.search", false);
-
-// Enable the Application panel
-pref("devtools.application.enabled", false);
-
-// The default Network Monitor UI settings
-pref("devtools.netmonitor.panes-network-details-width", 550);
-pref("devtools.netmonitor.panes-network-details-height", 450);
-pref("devtools.netmonitor.panes-search-width", 550);
-pref("devtools.netmonitor.panes-search-height", 450);
-pref("devtools.netmonitor.filters", "[\"all\"]");
-pref("devtools.netmonitor.visibleColumns",
-  "[\"status\",\"method\",\"domain\",\"file\",\"cause\",\"type\",\"transferred\",\"contentSize\",\"waterfall\"]"
-);
-pref("devtools.netmonitor.columnsData",
-  '[{"name":"status","minWidth":30,"width":5}, {"name":"method","minWidth":30,"width":5}, {"name":"domain","minWidth":30,"width":10}, {"name":"file","minWidth":30,"width":25}, {"name":"url","minWidth":30,"width":25}, {"name":"cause","minWidth":30,"width":10},{"name":"type","minWidth":30,"width":5},{"name":"transferred","minWidth":30,"width":10},{"name":"contentSize","minWidth":30,"width":5},{"name":"waterfall","minWidth":150,"width":25}]');
-pref("devtools.netmonitor.ws.payload-preview-height", 128);
-pref("devtools.netmonitor.ws.visibleColumns",
-  '["data", "time"]'
-);
-pref("devtools.netmonitor.ws.displayed-frames.limit", 500);
-
-pref("devtools.netmonitor.response.ui.limit", 10240);
-
-// Save request/response bodies yes/no.
-pref("devtools.netmonitor.saveRequestAndResponseBodies", true);
-
-// The default Network monitor HAR export setting
-pref("devtools.netmonitor.har.defaultLogDir", "");
-pref("devtools.netmonitor.har.defaultFileName", "%hostname_Archive [%date]");
-pref("devtools.netmonitor.har.jsonp", false);
-pref("devtools.netmonitor.har.jsonpCallback", "");
-pref("devtools.netmonitor.har.includeResponseBodies", true);
-pref("devtools.netmonitor.har.compress", false);
-pref("devtools.netmonitor.har.forceExport", false);
-pref("devtools.netmonitor.har.pageLoadedTimeout", 1500);
-pref("devtools.netmonitor.har.enableAutoExportToFile", false);
-
-// Enable WebSocket monitoring in Nightly builds.
-#if defined(NIGHTLY_BUILD)
-pref("devtools.netmonitor.features.webSockets", true);
-#else
-pref("devtools.netmonitor.features.webSockets", false);
-#endif
-
-// Scratchpad settings
-// - recentFileMax: The maximum number of recently-opened files
-//                  stored. Setting this preference to 0 will not
-//                  clear any recent files, but rather hide the
-//                  'Open Recent'-menu.
-// - lineNumbers: Whether to show line numbers or not.
-// - wrapText: Whether to wrap text or not.
-// - showTrailingSpace: Whether to highlight trailing space or not.
-// - editorFontSize: Editor font size configuration.
-// - enableAutocompletion: Whether to enable JavaScript autocompletion.
-pref("devtools.scratchpad.recentFilesMax", 10);
-pref("devtools.scratchpad.lineNumbers", true);
-pref("devtools.scratchpad.wrapText", false);
-pref("devtools.scratchpad.showTrailingSpace", false);
-pref("devtools.scratchpad.editorFontSize", 12);
-pref("devtools.scratchpad.enableAutocompletion", true);
-
-// Enable the Storage Inspector
-pref("devtools.storage.enabled", true);
-
-// Enable the Style Editor.
-pref("devtools.styleeditor.enabled", true);
-pref("devtools.styleeditor.autocompletion-enabled", true);
-pref("devtools.styleeditor.showMediaSidebar", true);
-pref("devtools.styleeditor.mediaSidebarWidth", 238);
-pref("devtools.styleeditor.navSidebarWidth", 245);
-pref("devtools.styleeditor.transitions", true);
-
-// Screenshot Option Settings.
-pref("devtools.screenshot.clipboard.enabled", false);
-pref("devtools.screenshot.audio.enabled", true);
-
-// Enable Scratchpad
-pref("devtools.scratchpad.enabled", false);
-
-// Make sure the DOM panel is hidden by default
-pref("devtools.dom.enabled", false);
-
-// Enable the Accessibility panel.
-pref("devtools.accessibility.enabled", true);
-
-// Web console filters
-pref("devtools.webconsole.filter.error", true);
-pref("devtools.webconsole.filter.warn", true);
-pref("devtools.webconsole.filter.info", true);
-pref("devtools.webconsole.filter.log", true);
-pref("devtools.webconsole.filter.debug", true);
-pref("devtools.webconsole.filter.css", false);
-pref("devtools.webconsole.filter.net", false);
-pref("devtools.webconsole.filter.netxhr", false);
-
-// Webconsole autocomplete preference
-pref("devtools.webconsole.input.autocomplete",true);
-
-// Browser console filters
-pref("devtools.browserconsole.filter.error", true);
-pref("devtools.browserconsole.filter.warn", true);
-pref("devtools.browserconsole.filter.info", true);
-pref("devtools.browserconsole.filter.log", true);
-pref("devtools.browserconsole.filter.debug", true);
-pref("devtools.browserconsole.filter.css", false);
-pref("devtools.browserconsole.filter.net", false);
-pref("devtools.browserconsole.filter.netxhr", false);
-
-// Max number of inputs to store in web console history.
-pref("devtools.webconsole.inputHistoryCount", 300);
-
-// Persistent logging: |true| if you want the relevant tool to keep all of the
-// logged messages after reloading the page, |false| if you want the output to
-// be cleared each time page navigation happens.
-pref("devtools.webconsole.persistlog", false);
-pref("devtools.netmonitor.persistlog", false);
-
-// Web Console timestamp: |true| if you want the logs and instructions
-// in the Web Console to display a timestamp, or |false| to not display
-// any timestamps.
-pref("devtools.webconsole.timestampMessages", false);
-
-// Enable the webconsole sidebar toggle in Nightly builds.
-#if defined(NIGHTLY_BUILD)
-pref("devtools.webconsole.sidebarToggle", true);
-#else
-pref("devtools.webconsole.sidebarToggle", false);
-#endif
-
-// Enable editor mode in the console in Nightly builds.
-#if defined(NIGHTLY_BUILD)
-pref("devtools.webconsole.features.editor", true);
-#else
-pref("devtools.webconsole.features.editor", false);
-#endif
-
-// Saved editor mode state in the console.
-pref("devtools.webconsole.input.editor", false);
-
-// Editor width for webconsole and browserconsole
-pref("devtools.webconsole.input.editorWidth", 0);
-pref("devtools.browserconsole.input.editorWidth", 0);
-
-// Disable the new performance recording panel by default
-pref("devtools.performance.new-panel-enabled", false);
-
-// Enable message grouping in the console, true by default
-pref("devtools.webconsole.groupWarningMessages", true);
-
-// Saved state of the Display content messages checkbox in the browser console.
-pref("devtools.browserconsole.contentMessages", false);
-
-// Enable client-side mapping service for source maps
-pref("devtools.source-map.client-service.enabled", true);
-
-// The number of lines that are displayed in the web console.
-pref("devtools.hud.loglimit", 10000);
-
-// The developer tools editor configuration:
-// - tabsize: how many spaces to use when a Tab character is displayed.
-// - expandtab: expand Tab characters to spaces.
-// - keymap: which keymap to use (can be 'default', 'emacs' or 'vim')
-// - autoclosebrackets: whether to permit automatic bracket/quote closing.
-// - detectindentation: whether to detect the indentation from the file
-// - enableCodeFolding: Whether to enable code folding or not.
-pref("devtools.editor.tabsize", 2);
-pref("devtools.editor.expandtab", true);
-pref("devtools.editor.keymap", "default");
-pref("devtools.editor.autoclosebrackets", true);
-pref("devtools.editor.detectindentation", true);
-pref("devtools.editor.enableCodeFolding", true);
-pref("devtools.editor.autocomplete", true);
-
-// The angle of the viewport.
-pref("devtools.responsive.viewport.angle", 0);
-// The width of the viewport.
-pref("devtools.responsive.viewport.width", 320);
-// The height of the viewport.
-pref("devtools.responsive.viewport.height", 480);
-// The pixel ratio of the viewport.
-pref("devtools.responsive.viewport.pixelRatio", 0);
-// Whether or not the viewports are left aligned.
-pref("devtools.responsive.leftAlignViewport.enabled", false);
-// Whether to reload when touch simulation is toggled
-pref("devtools.responsive.reloadConditions.touchSimulation", false);
-// Whether to reload when user agent is changed
-pref("devtools.responsive.reloadConditions.userAgent", false);
-// Whether to show the notification about reloading to apply emulation
-pref("devtools.responsive.reloadNotification.enabled", true);
-// Whether or not touch simulation is enabled.
-pref("devtools.responsive.touchSimulation.enabled", false);
-// Whether or not meta viewport is enabled, if and only if touchSimulation
-// is also enabled.
-pref("devtools.responsive.metaViewport.enabled", false);
-// The user agent of the viewport.
-pref("devtools.responsive.userAgent", "");
-
-// Whether to show the settings onboarding tooltip only in release or beta builds.
-#if defined(RELEASE_OR_BETA)
-pref("devtools.responsive.show-setting-tooltip", true);
-#else
-pref("devtools.responsive.show-setting-tooltip", false);
-#endif
-// Show the custom user agent input in Nightly builds.
-#if defined(NIGHTLY_BUILD)
-pref("devtools.responsive.showUserAgentInput", true);
-#else
-pref("devtools.responsive.showUserAgentInput", false);
-#endif
-
-// Show tab debug targets for This Firefox (on by default for local builds).
-#ifdef MOZILLA_OFFICIAL
-  pref("devtools.aboutdebugging.local-tab-debugging", false);
-#else
-  pref("devtools.aboutdebugging.local-tab-debugging", true);
-#endif
-
-// Show process debug targets.
-pref("devtools.aboutdebugging.process-debugging", true);
-// Stringified array of network locations that users can connect to.
-pref("devtools.aboutdebugging.network-locations", "[]");
-// Debug target pane collapse/expand settings.
-pref("devtools.aboutdebugging.collapsibilities.installedExtension", false);
-pref("devtools.aboutdebugging.collapsibilities.otherWorker", false);
-pref("devtools.aboutdebugging.collapsibilities.serviceWorker", false);
-pref("devtools.aboutdebugging.collapsibilities.sharedWorker", false);
-pref("devtools.aboutdebugging.collapsibilities.tab", false);
-pref("devtools.aboutdebugging.collapsibilities.temporaryExtension", false);
-
-// about:debugging: only show system and hidden extensions in local builds by default.
-#ifdef MOZILLA_OFFICIAL
-  pref("devtools.aboutdebugging.showHiddenAddons", false);
-#else
-  pref("devtools.aboutdebugging.showHiddenAddons", true);
-#endif
-
-// Map top-level await expressions in the console
-pref("devtools.debugger.features.map-await-expression", true);
-
-// Disable autohide for DevTools popups and tooltips.
-// This is currently not exposed by any UI to avoid making
-// about:devtools-toolbox tabs unusable by mistake.
-pref("devtools.popup.disable_autohide", false);
-
-// Load the DevTools toolbox in a frame with type=content instead of type=chrome
-// See Bug 1539979 for more details.
-// We keep the option of running devtools in a chrome frame while we fix racy
-// tests that started failing when using type=content, but this ultimately should
-// be removed.
-pref("devtools.toolbox.content-frame", true);
diff --git a/devtools/client/preferences/moz.build b/devtools/client/preferences/moz.build
index 0d36d2523f6b..1af1809dd0a1 100644
--- a/devtools/client/preferences/moz.build
+++ b/devtools/client/preferences/moz.build
@@ -4,10 +4,6 @@
 # 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/.
 
-JS_PREFERENCE_PP_FILES += [
-    'devtools-client.js'
-]
-
 JS_PREFERENCE_FILES += [
     'debugger.js',
 ]
diff --git a/devtools/client/webide/moz.build b/devtools/client/webide/moz.build
index 07c225af0e7e..275406f861bc 100644
--- a/devtools/client/webide/moz.build
+++ b/devtools/client/webide/moz.build
@@ -7,7 +7,6 @@
 DIRS += [
     'content',
     'modules',
-    'preferences',
     'themes',
 ]
 
diff --git a/devtools/client/webide/preferences/moz.build b/devtools/client/webide/preferences/moz.build
deleted file mode 100644
index b6236b291c12..000000000000
--- a/devtools/client/webide/preferences/moz.build
+++ /dev/null
@@ -1,9 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-JS_PREFERENCE_FILES += [
-    'webide.js',
-]
diff --git a/devtools/client/webide/preferences/webide.js b/devtools/client/webide/preferences/webide.js
deleted file mode 100644
index d0537ab6d11b..000000000000
--- a/devtools/client/webide/preferences/webide.js
+++ /dev/null
@@ -1,13 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
-   License, v. 2.0. If a copy of the MPL was not distributed with this
-   file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-pref("devtools.webide.templatesURL", "https://code.cdn.mozilla.net/templates/list.json");
-pref("devtools.webide.autoinstallADBExtension", true);
-pref("devtools.webide.autoConnectRuntime", true);
-pref("devtools.webide.restoreLastProject", true);
-pref("devtools.webide.enableLocalRuntime", false);
-pref("devtools.webide.lastConnectedRuntime", "");
-pref("devtools.webide.lastSelectedProject", "");
-pref("devtools.webide.zoom", "1");
-pref("devtools.webide.busyTimeout", 10000);
diff --git a/devtools/docs/preferences.md b/devtools/docs/preferences.md
index 1e30c0980275..93ebcf5395aa 100644
--- a/devtools/docs/preferences.md
+++ b/devtools/docs/preferences.md
@@ -68,19 +68,12 @@ These APIs are very similar for each preference type.
 
 ## Create a new preference
 
-To create a new preference, it should be assigned a default value. Default preferences are
-defined in preferences files such as:
-- devtools/client/preferences/devtools-client.js
-- devtools/client/preferences/debugger.js
-- devtools/shared/preferences/devtools-shared.js
-- devtools/startup/preferences/devtools-startup.js
-
-Most new preferences should go in devtools/client/preferences/devtools-client.js. Debugger
-specific preferences should go in devtools/client/preferences/debugger.js. If a preference
-should be available even when the client for DevTools is not shipped (for instance on
-Fennec) the preference should go to devtools/shared/preferences/devtools-shared.js.
-Finally if a preference needs to be available very early during the Firefox startup
-sequence, it should go in devtools/startup/preferences/devtools-startup.js.
+Debugger-specific preferences should go in
+devtools/client/preferences/debugger.js. Beyond that, most new preferences
+should go in browser/app/profile/firefox.js, which is for desktop Firefox only.
+If a preference should be available even when the client for DevTools is not
+shipped (for instance on Fennec) it should go in modules/libpref/init/all.js,
+which is for preferences that go in all products.
 
 ### Projects using Launchpad
 
diff --git a/devtools/shared/preferences/README.md b/devtools/shared/preferences/README.md
deleted file mode 100644
index 58c9a2538ff6..000000000000
--- a/devtools/shared/preferences/README.md
+++ /dev/null
@@ -1,4 +0,0 @@
-# How is devtools-shared loaded?
-
-This preference file is included via modules/libpref/greprefs.js which guarantees it will
-be loaded on all distributions, including xpcshell binary.
diff --git a/devtools/shared/preferences/devtools-shared.js b/devtools/shared/preferences/devtools-shared.js
deleted file mode 100644
index acd878da9bf0..000000000000
--- a/devtools/shared/preferences/devtools-shared.js
+++ /dev/null
@@ -1,73 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-// Tells if DevTools have been explicitely enabled by the user.
-// This pref allows to disable all features related to DevTools
-// for users that never use them.
-// Until bug 1361080 lands, we always consider them enabled.
-pref("devtools.enabled", true);
-
-// Enable deprecation warnings.
-pref("devtools.errorconsole.deprecation_warnings", true);
-
-#ifdef NIGHTLY_BUILD
-// Don't show the Browser Toolbox prompt on local builds / nightly
-pref("devtools.debugger.prompt-connection", false, sticky);
-#else
-pref("devtools.debugger.prompt-connection", true, sticky);
-#endif
-
-#ifdef MOZILLA_OFFICIAL
-// Disable debugging chrome
-pref("devtools.chrome.enabled", false, sticky);
-// Disable remote debugging connections
-pref("devtools.debugger.remote-enabled", false, sticky);
-#else
-// In local builds, enable the browser toolbox by default
-pref("devtools.chrome.enabled", true, sticky);
-pref("devtools.debugger.remote-enabled", true, sticky);
-#endif
-
-// Disable remote debugging protocol logging
-pref("devtools.debugger.log", false);
-pref("devtools.debugger.log.verbose", false);
-
-pref("devtools.debugger.remote-port", 6000);
-pref("devtools.debugger.remote-websocket", false);
-// Force debugger server binding on the loopback interface
-pref("devtools.debugger.force-local", true);
-
-// Limit for intercepted request and response bodies (1 MB)
-// Possible values:
-// 0 => the response body has no limit
-// n => represents max number of bytes stored
-pref("devtools.netmonitor.responseBodyLimit", 1048576);
-pref("devtools.netmonitor.requestBodyLimit", 1048576);
-
-// Limit for WebSocket frames (100 KB)
-pref("devtools.netmonitor.ws.messageDataLimit", 100000);
-
-// DevTools default color unit
-pref("devtools.defaultColorUnit", "authored");
-
-// Used for devtools debugging
-pref("devtools.dump.emit", false);
-
-// Disable device discovery logging
-pref("devtools.discovery.log", false);
-// Whether to scan for DevTools devices via WiFi
-pref("devtools.remote.wifi.scan", true);
-// Client must complete TLS handshake within this window (ms)
-pref("devtools.remote.tls-handshake-timeout", 10000);
-
-// The extension ID for devtools-adb-extension
-pref("devtools.remote.adb.extensionID", "adb@mozilla.org");
-// The URL for for devtools-adb-extension (overridden in tests to a local path)
-pref("devtools.remote.adb.extensionURL", "https://ftp.mozilla.org/pub/mozilla.org/labs/devtools/adb-extension/#OS#/adb-extension-latest-#OS#.xpi");
-
-// URL of the remote JSON catalog used for device simulation
-pref("devtools.devices.url", "https://code.cdn.mozilla.net/devices/devices.json");
-
-// Enable Inactive CSS detection; used both by the client and the server.
-pref("devtools.inspector.inactive.css.enabled", true);
diff --git a/devtools/startup/moz.build b/devtools/startup/moz.build
index 7824b57c8b94..d578972cdf14 100644
--- a/devtools/startup/moz.build
+++ b/devtools/startup/moz.build
@@ -6,10 +6,6 @@
 
 JAR_MANIFESTS += ['jar.mn']
 
-DIRS += [
-    'preferences',
-]
-
 # Register the startup components only for 'all' builds.
 if CONFIG['MOZ_DEVTOOLS'] == 'all':
     EXTRA_JS_MODULES += [
diff --git a/devtools/startup/preferences/devtools-startup.js b/devtools/startup/preferences/devtools-startup.js
deleted file mode 100644
index 4d3616144b30..000000000000
--- a/devtools/startup/preferences/devtools-startup.js
+++ /dev/null
@@ -1,20 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-// The preferences defined here should be used by the components in devtools-startup.
-// devtools-startup is always shipped and those preferences will always be available.
-
-// Enable the JSON View tool (an inspector for application/json documents).
-pref("devtools.jsonview.enabled", true);
-
-// Default theme ("dark" or "light")
-#ifdef MOZ_DEV_EDITION
-pref("devtools.theme", "dark", sticky);
-#else
-pref("devtools.theme", "light", sticky);
-#endif
-
-// Completely disable DevTools entry points, as well as all DevTools command line
-// arguments This should be merged with devtools.enabled, see Bug 1440675.
-pref("devtools.policy.disabled", false);
diff --git a/devtools/startup/preferences/moz.build b/devtools/startup/preferences/moz.build
deleted file mode 100644
index e76962642e78..000000000000
--- a/devtools/startup/preferences/moz.build
+++ /dev/null
@@ -1,9 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-JS_PREFERENCE_PP_FILES += [
-    'devtools-startup.js'
-]
diff --git a/modules/libpref/greprefs.js b/modules/libpref/greprefs.js
index 9fb53498f087..942e96856791 100644
--- a/modules/libpref/greprefs.js
+++ b/modules/libpref/greprefs.js
@@ -1,2 +1 @@
 #include init/all.js
-#include ../../devtools/shared/preferences/devtools-shared.js
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 8adb4582185b..62f7ee9b0877 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -5633,3 +5633,87 @@ pref("remote.force-local", true);
 // "Config", "Info", "Warn", "Error", and "Fatal". The value is treated
 // case-sensitively.
 pref("remote.log.level", "Info");
+
+// Enable the JSON View tool (an inspector for application/json documents).
+pref("devtools.jsonview.enabled", true);
+
+// Default theme ("dark" or "light").
+#ifdef MOZ_DEV_EDITION
+  pref("devtools.theme", "dark", sticky);
+#else
+  pref("devtools.theme", "light", sticky);
+#endif
+
+// Completely disable DevTools entry points, as well as all DevTools command
+// line arguments This should be merged with devtools.enabled, see Bug 1440675.
+pref("devtools.policy.disabled", false);
+
+// Tells if DevTools have been explicitely enabled by the user. This pref
+// allows to disable all features related to DevTools for users that never use
+// them. Until bug 1361080 lands, we always consider them enabled.
+pref("devtools.enabled", true);
+
+// Enable deprecation warnings.
+pref("devtools.errorconsole.deprecation_warnings", true);
+
+#ifdef NIGHTLY_BUILD
+  // Don't show the Browser Toolbox prompt on local builds / nightly.
+  pref("devtools.debugger.prompt-connection", false, sticky);
+#else
+  pref("devtools.debugger.prompt-connection", true, sticky);
+#endif
+
+#ifdef MOZILLA_OFFICIAL
+  // Disable debugging chrome.
+  pref("devtools.chrome.enabled", false, sticky);
+  // Disable remote debugging connections.
+  pref("devtools.debugger.remote-enabled", false, sticky);
+#else
+  // In local builds, enable the browser toolbox by default.
+  pref("devtools.chrome.enabled", true, sticky);
+  pref("devtools.debugger.remote-enabled", true, sticky);
+#endif
+
+// Disable remote debugging protocol logging.
+pref("devtools.debugger.log", false);
+pref("devtools.debugger.log.verbose", false);
+
+pref("devtools.debugger.remote-port", 6000);
+pref("devtools.debugger.remote-websocket", false);
+// Force debugger server binding on the loopback interface.
+pref("devtools.debugger.force-local", true);
+
+// Limit for intercepted request and response bodies (1 MB).
+// Possible values:
+// 0 => the response body has no limit
+// n => represents max number of bytes stored
+pref("devtools.netmonitor.responseBodyLimit", 1048576);
+pref("devtools.netmonitor.requestBodyLimit", 1048576);
+
+// Limit for WebSocket frames (100 KB).
+pref("devtools.netmonitor.ws.messageDataLimit", 100000);
+
+// DevTools default color unit.
+pref("devtools.defaultColorUnit", "authored");
+
+// Used for devtools debugging.
+pref("devtools.dump.emit", false);
+
+// Disable device discovery logging.
+pref("devtools.discovery.log", false);
+// Whether to scan for DevTools devices via WiFi.
+pref("devtools.remote.wifi.scan", true);
+// Client must complete TLS handshake within this window (ms).
+pref("devtools.remote.tls-handshake-timeout", 10000);
+
+// The extension ID for devtools-adb-extension.
+pref("devtools.remote.adb.extensionID", "adb@mozilla.org");
+// The URL for for devtools-adb-extension (overridden in tests to a local
+// path).
+pref("devtools.remote.adb.extensionURL", "https://ftp.mozilla.org/pub/mozilla.org/labs/devtools/adb-extension/#OS#/adb-extension-latest-#OS#.xpi");
+
+// URL of the remote JSON catalog used for device simulation.
+pref("devtools.devices.url", "https://code.cdn.mozilla.net/devices/devices.json");
+
+// Enable Inactive CSS detection; used both by the client and the server.
+pref("devtools.inspector.inactive.css.enabled", true);