--- a/devtools/client/storage/test/browser_storage_indexeddb_duplicate_names.js
+++ b/devtools/client/storage/test/browser_storage_indexeddb_duplicate_names.js
@@ -3,16 +3,20 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 // Test to verify that indexedDBs with duplicate names (different types / paths)
 // work as expected.
 
 "use strict";
 
 add_task(async function() {
+  await SpecialPowers.pushPrefEnv({
+    set: [["dom.indexedDB.storageOption.enabled", true]]
+  });
+
   const TESTPAGE = MAIN_DOMAIN + "storage-indexeddb-duplicate-names.html";
 
   setPermission(TESTPAGE, "indexedDB");
 
   await openTabAndSetupStorage(TESTPAGE);
 
   await checkState([
     [

--- a/dom/base/DOMPrefsInternal.h
+++ b/dom/base/DOMPrefsInternal.h
@@ -36,16 +36,17 @@ DOM_PREF(StreamsEnabled, "dom.streams.en
 DOM_PREF(OffscreenCanvasEnabled, "gfx.offscreencanvas.enabled")
 DOM_PREF(WebkitBlinkDirectoryPickerEnabled, "dom.webkitBlink.dirPicker.enabled")
 DOM_PREF(NetworkInformationEnabled, "dom.netinfo.enabled")
 DOM_PREF(FetchObserverEnabled, "dom.fetchObserver.enabled")
 DOM_PREF(ResistFingerprintingEnabled, "privacy.resistFingerprinting")
 DOM_PREF(EnableAutoDeclineCanvasPrompts, "privacy.resistFingerprinting.autoDeclineNoUserInputCanvasPrompts")
 DOM_PREF(DevToolsEnabled, "devtools.enabled")
 DOM_PREF(PerformanceObserverEnabled, "dom.enable_performance_observer")
+DOM_PREF(IndexedDBStorageOptionsEnabled, "dom.indexedDB.storageOption.enabled")
 
 DOM_WEBIDL_PREF(ImageBitmapExtensionsEnabled)
 DOM_WEBIDL_PREF(DOMCachesEnabled)
 DOM_WEBIDL_PREF(NotificationEnabledInServiceWorkers)
 DOM_WEBIDL_PREF(NotificationRIEnabled)
 DOM_WEBIDL_PREF(ServiceWorkersEnabled)
 DOM_WEBIDL_PREF(StorageManagerEnabled)
 DOM_WEBIDL_PREF(PromiseRejectionEventsEnabled)

--- a/dom/indexedDB/IDBFactory.cpp
+++ b/dom/indexedDB/IDBFactory.cpp
@@ -688,21 +688,37 @@ IDBFactory::OpenInternal(JSContext* aCx,
   PersistenceType persistenceType;
 
   bool isInternal = principalInfo.type() == PrincipalInfo::TSystemPrincipalInfo;
   if (!isInternal && principalInfo.type() == PrincipalInfo::TContentPrincipalInfo) {
     nsCString origin = principalInfo.get_ContentPrincipalInfo().originNoSuffix();
     isInternal = QuotaManager::IsOriginInternal(origin);
   }
 
+  // Allow storage attributes for add-ons independent of the pref.
+  // This works in the main thread only, workers don't have the principal.
+  bool isAddon = false;
+  if (NS_IsMainThread()) {
+    // aPrincipal is passed inconsistently, so even when we are already on
+    // the main thread, we may have been passed a null aPrincipal.
+    nsCOMPtr<nsIPrincipal> principal = PrincipalInfoToPrincipal(principalInfo);
+    if (principal) {
+      nsAutoString addonId;
+      Unused << NS_WARN_IF(NS_FAILED(principal->GetAddonId(addonId)));
+      isAddon = !addonId.IsEmpty();
+    }
+  }
+
   if (isInternal) {
     // Chrome privilege and internal origins always get persistent storage.
     persistenceType = PERSISTENCE_TYPE_PERSISTENT;
+  } else if (isAddon || DOMPrefs::IndexedDBStorageOptionsEnabled()) {
+    persistenceType = PersistenceTypeFromStorage(aStorageType);
   } else {
-    persistenceType = PersistenceTypeFromStorage(aStorageType);
+    persistenceType = PERSISTENCE_TYPE_DEFAULT;
   }
 
   DatabaseMetadata& metadata = commonParams.metadata();
   metadata.name() = aName;
   metadata.persistenceType() = persistenceType;
 
   FactoryRequestParams params;
   if (aDeleting) {

--- a/dom/indexedDB/test/browser.ini
+++ b/dom/indexedDB/test/browser.ini
@@ -1,9 +1,11 @@
 [DEFAULT]
+prefs =
+  dom.indexedDB.storageOption.enabled=true
 skip-if = (buildapp != "browser")
 support-files =
   head.js
   browser_forgetThisSiteAdd.html
   browser_forgetThisSiteGet.html
   browserHelpers.js
   browser_permissionsPrompt.html
   browser_permissionsSharedWorker.html

--- a/dom/indexedDB/test/mochitest.ini
+++ b/dom/indexedDB/test/mochitest.ini
@@ -1,13 +1,15 @@
 # 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/.
 
 [DEFAULT]
+prefs =
+  dom.indexedDB.storageOption.enabled=true
 support-files =
   bfcache_page1.html
   bfcache_page2.html
   blob_worker_crash_iframe.html
   error_events_abort_transactions_iframe.html
   event_propagation_iframe.html
   exceptions_in_events_iframe.html
   file.js

--- a/dom/indexedDB/test/unit/test_defaultStorageUpgrade.js
+++ b/dom/indexedDB/test/unit/test_defaultStorageUpgrade.js
@@ -2,16 +2,21 @@
  * Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
 var testGenerator = testSteps();
 
 function* testSteps()
 {
+  Services.prefs.setBoolPref("dom.indexedDB.storageOption.enabled", true);
+  registerCleanupFunction(() => {
+    Services.prefs.clearUserPref("dom.indexedDB.storageOption.enabled");
+  });
+
   const openParams = [
     // This one lives in storage/default/http+++localhost
     { url: "http://localhost", dbName: "dbA", dbVersion: 1 },
 
     // This one lives in storage/default/http+++www.mozilla.org
     { url: "http://www.mozilla.org", dbName: "dbB", dbVersion: 1 },
 
     // This one lives in storage/default/http+++www.mozilla.org+8080

--- a/dom/indexedDB/test/unit/test_metadata2Restore.js
+++ b/dom/indexedDB/test/unit/test_metadata2Restore.js
@@ -2,16 +2,21 @@
  * Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
 var testGenerator = testSteps();
 
 function* testSteps()
 {
+  Services.prefs.setBoolPref("dom.indexedDB.storageOption.enabled", true);
+  registerCleanupFunction(() => {
+    Services.prefs.clearUserPref("dom.indexedDB.storageOption.enabled");
+  });
+
   const openParams = [
     // This one lives in storage/permanent/chrome
     // The .metadata-v2 file was intentionally removed for this origin directory
     // to test restoring.
     { dbName: "dbA",
       dbOptions: { version: 1, storage: "persistent" } },
 
     // This one lives in storage/temporary/http+++localhost

--- a/dom/indexedDB/test/unit/test_metadataRestore.js
+++ b/dom/indexedDB/test/unit/test_metadataRestore.js
@@ -2,16 +2,21 @@
  * Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
 var testGenerator = testSteps();
 
 function* testSteps()
 {
+  Services.prefs.setBoolPref("dom.indexedDB.storageOption.enabled", true);
+  registerCleanupFunction(() => {
+    Services.prefs.clearUserPref("dom.indexedDB.storageOption.enabled");
+  });
+
   const openParams = [
     // This one lives in storage/permanent/chrome
     { dbName: "dbA",
       dbOptions: { version: 1, storage: "persistent" } },
 
     // This one lives in storage/temporary/http+++localhost
     { url: "http://localhost", dbName: "dbB",
       dbOptions: { version: 1, storage: "temporary" } },

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -133,16 +133,18 @@ pref("dom.indexedDB.enabled", true);
 // Whether or not indexedDB experimental features are enabled.
 pref("dom.indexedDB.experimental", false);
 // Enable indexedDB logging.
 pref("dom.indexedDB.logging.enabled", true);
 // Detailed output in log messages.
 pref("dom.indexedDB.logging.details", true);
 // Enable profiler marks for indexedDB events.
 pref("dom.indexedDB.logging.profiler-marks", false);
+// Enable passing the "storage" option to indexedDB.open.
+pref("dom.indexedDB.storageOption.enabled", false);
 
 // Whether or not File Handle is enabled.
 pref("dom.fileHandle.enabled", true);
 
 // Whether window.onappinstalled from "W3C Web Manifest" is enabled
 pref("dom.manifest.onappinstalled", false);
 
 // Whether or not selection events are enabled