Bug 1803800, r=markh

Differential Revision: https://phabricator.services.mozilla.com/D163931

services/common/hawkrequest.js

@@ -82,8 +82,6 @@ var HAWKAuthenticatedRESTRequest = function HawkAuthenticatedRESTRequest(
   this._intl = getIntl();
 };
 HAWKAuthenticatedRESTRequest.prototype = {
-  __proto__: RESTRequest.prototype,
-
   async dispatch(method, data) {
     let contentType = "text/plain";
     if (method == "POST" || method == "PUT" || method == "PATCH") {
@@ -117,6 +115,11 @@ HAWKAuthenticatedRESTRequest.prototype = {
   },
 };
 
+Object.setPrototypeOf(
+  HAWKAuthenticatedRESTRequest.prototype,
+  RESTRequest.prototype
+);
+
 /**
  * Generic function to derive Hawk credentials.
  *

services/common/modules-testing/logging.js

@@ -32,7 +32,7 @@ function initTestLogging(level) {
       );
     },
   };
-  LogStats.prototype.__proto__ = new Log.BasicFormatter();
+  Object.setPrototypeOf(LogStats.prototype, new Log.BasicFormatter());
 
   let log = Log.repository.rootLogger;
   let logStats = new LogStats();

services/common/rest.js

@@ -710,8 +710,6 @@ function TokenAuthenticatedRESTRequest(uri, authToken, extra) {
   this.extra = extra || {};
 }
 TokenAuthenticatedRESTRequest.prototype = {
-  __proto__: RESTRequest.prototype,
-
   async dispatch(method, data) {
     let sig = await lazy.CryptoUtils.computeHTTPMACSHA1(
       this.authToken.id,
@@ -726,3 +724,8 @@ TokenAuthenticatedRESTRequest.prototype = {
     return super.dispatch(method, data);
   },
 };
+
+Object.setPrototypeOf(
+  TokenAuthenticatedRESTRequest.prototype,
+  RESTRequest.prototype
+);

services/fxaccounts/tests/xpcshell/test_accounts.js

@@ -178,10 +178,11 @@ function MockFxAccountsClient() {
 
   FxAccountsClient.apply(this);
 }
-MockFxAccountsClient.prototype = {
-  __proto__: FxAccountsClient.prototype,
-};
-
+MockFxAccountsClient.prototype = {};
+Object.setPrototypeOf(
+  MockFxAccountsClient.prototype,
+  FxAccountsClient.prototype
+);
 /*
  * We need to mock the FxAccounts module's interfaces to external
  * services, such as storage and the FxAccounts client.  We also

services/fxaccounts/tests/xpcshell/test_accounts_device_registration.js

@@ -120,9 +120,11 @@ function MockFxAccountsClient(device) {
 
   FxAccountsClient.apply(this);
 }
-MockFxAccountsClient.prototype = {
-  __proto__: FxAccountsClient.prototype,
-};
+MockFxAccountsClient.prototype = {};
+Object.setPrototypeOf(
+  MockFxAccountsClient.prototype,
+  FxAccountsClient.prototype
+);
 
 async function MockFxAccounts(credentials, device = {}) {
   let fxa = new FxAccounts({

services/fxaccounts/tests/xpcshell/test_commands.js

@@ -45,9 +45,11 @@ function MockFxAccountsClient() {
   FxAccountsClient.apply(this);
 }
 
-MockFxAccountsClient.prototype = {
-  __proto__: FxAccountsClient.prototype,
-};
+MockFxAccountsClient.prototype = {};
+Object.setPrototypeOf(
+  MockFxAccountsClient.prototype,
+  FxAccountsClient.prototype
+);
 
 add_task(async function test_sendtab_isDeviceCompatible() {
   const sendTab = new SendTab(null, null);

services/fxaccounts/tests/xpcshell/test_oauth_token_storage.js

@@ -88,9 +88,11 @@ function MockFxAccountsClient() {
   FxAccountsClient.apply(this);
 }
 
-MockFxAccountsClient.prototype = {
-  __proto__: FxAccountsClient.prototype,
-};
+MockFxAccountsClient.prototype = {};
+Object.setPrototypeOf(
+  MockFxAccountsClient.prototype,
+  FxAccountsClient.prototype
+);
 
 function MockFxAccounts(device = {}) {
   return new FxAccounts({

services/fxaccounts/tests/xpcshell/test_oauth_tokens.js

@@ -108,9 +108,11 @@ function MockFxAccountsClient(activeTokens) {
   FxAccountsClient.apply(this);
 }
 
-MockFxAccountsClient.prototype = {
-  __proto__: FxAccountsClient.prototype,
-};
+MockFxAccountsClient.prototype = {};
+Object.setPrototypeOf(
+  MockFxAccountsClient.prototype,
+  FxAccountsClient.prototype
+);
 
 function MockFxAccounts() {
   // The FxA "auth" and "oauth" servers both share the same db of tokens,

services/sync/modules-testing/rotaryengine.js

@@ -31,9 +31,8 @@ const { SerializableSet, Utils } = ChromeUtils.import(
 function RotaryRecord(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
-RotaryRecord.prototype = {
-  __proto__: CryptoWrapper.prototype,
-};
+RotaryRecord.prototype = {};
+Object.setPrototypeOf(RotaryRecord.prototype, CryptoWrapper.prototype);
 Utils.deferGetSet(RotaryRecord, "cleartext", ["denomination"]);
 
 function RotaryStore(name, engine) {
@@ -41,8 +40,6 @@ function RotaryStore(name, engine) {
   this.items = {};
 }
 RotaryStore.prototype = {
-  __proto__: Store.prototype,
-
   async create(record) {
     this.items[record.id] = record.denomination;
   },
@@ -92,12 +89,13 @@ RotaryStore.prototype = {
   },
 };
 
+Object.setPrototypeOf(RotaryStore.prototype, Store.prototype);
+
 function RotaryTracker(name, engine) {
   LegacyTracker.call(this, name, engine);
 }
-RotaryTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-};
+RotaryTracker.prototype = {};
+Object.setPrototypeOf(RotaryTracker.prototype, LegacyTracker.prototype);
 
 function RotaryEngine(service) {
   SyncEngine.call(this, "Rotary", service);
@@ -106,7 +104,6 @@ function RotaryEngine(service) {
   this.previousFailed = new SerializableSet();
 }
 RotaryEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: RotaryStore,
   _trackerObj: RotaryTracker,
   _recordObj: RotaryRecord,
@@ -126,3 +123,4 @@ RotaryEngine.prototype = {
     return null;
   },
 };
+Object.setPrototypeOf(RotaryEngine.prototype, SyncEngine.prototype);

services/sync/modules-testing/utils.js

@@ -251,11 +251,14 @@ var configureFxAccountIdentity = function(
     FxAccountsClient.apply(this);
   };
   MockFxAccountsClient.prototype = {
-    __proto__: FxAccountsClient.prototype,
     accountStatus() {
       return Promise.resolve(true);
     },
   };
+  Object.setPrototypeOf(
+    MockFxAccountsClient.prototype,
+    FxAccountsClient.prototype
+  );
   let mockFxAClient = new MockFxAccountsClient();
   fxa._internal._fxAccountsClient = mockFxAClient;
 

services/sync/modules/bridged_engine.js

@@ -317,8 +317,6 @@ function BridgedEngine(name, service) {
 }
 
 BridgedEngine.prototype = {
-  __proto__: SyncEngine.prototype,
-
   /**
    * The Rust implemented bridge. Must be set by the engine which subclasses us.
    */
@@ -494,6 +492,7 @@ BridgedEngine.prototype = {
     await this._bridge.reset();
   },
 };
+Object.setPrototypeOf(BridgedEngine.prototype, SyncEngine.prototype);
 
 function transformError(code, message) {
   switch (code) {

services/sync/modules/engines.js

@@ -220,8 +220,6 @@ function LegacyTracker(name, engine) {
 }
 
 LegacyTracker.prototype = {
-  __proto__: Tracker.prototype,
-
   get ignoreAll() {
     return this._ignoreAll;
   },
@@ -333,6 +331,7 @@ LegacyTracker.prototype = {
     await this._storage.finalize();
   },
 };
+Object.setPrototypeOf(LegacyTracker.prototype, Tracker.prototype);
 
 /**
  * The Store serves as the interface between Sync and stored data.

services/sync/modules/engines/addons.js

@@ -110,9 +110,9 @@ function AddonRecord(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
 AddonRecord.prototype = {
-  __proto__: CryptoWrapper.prototype,
   _logName: "Record.Addon",
 };
+Object.setPrototypeOf(AddonRecord.prototype, CryptoWrapper.prototype);
 
 Utils.deferGetSet(AddonRecord, "cleartext", [
   "addonID",
@@ -137,7 +137,6 @@ function AddonsEngine(service) {
   this._reconciler = new AddonsReconciler(this._tracker.asyncObserver);
 }
 AddonsEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: AddonsStore,
   _trackerObj: AddonsTracker,
   _recordObj: AddonRecord,
@@ -266,6 +265,7 @@ AddonsEngine.prototype = {
     return this._store.isAddonSyncable(addon, ignoreRepoCheck);
   },
 };
+Object.setPrototypeOf(AddonsEngine.prototype, SyncEngine.prototype);
 
 /**
  * This is the primary interface between Sync and the Addons Manager.
@@ -277,8 +277,6 @@ function AddonsStore(name, engine) {
   Store.call(this, name, engine);
 }
 AddonsStore.prototype = {
-  __proto__: Store.prototype,
-
   // Define the add-on types (.type) that we support.
   _syncableTypes: ["extension", "theme"],
 
@@ -728,6 +726,8 @@ AddonsStore.prototype = {
   },
 };
 
+Object.setPrototypeOf(AddonsStore.prototype, Store.prototype);
+
 /**
  * The add-ons tracker keeps track of real-time changes to add-ons.
  *
@@ -737,8 +737,6 @@ function AddonsTracker(name, engine) {
   LegacyTracker.call(this, name, engine);
 }
 AddonsTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-
   get reconciler() {
     return this.engine._reconciler;
   },
@@ -782,6 +780,8 @@ AddonsTracker.prototype = {
   },
 };
 
+Object.setPrototypeOf(AddonsTracker.prototype, LegacyTracker.prototype);
+
 class AddonValidator extends CollectionValidator {
   constructor(engine = null) {
     super("addons", "id", ["addonID", "enabled", "applicationID", "source"]);

services/sync/modules/engines/bookmarks.js

@@ -116,7 +116,7 @@ PlacesItem.prototype = {
 
     // Convert the abstract places item to the actual object type
     if (!this.deleted) {
-      this.__proto__ = this.getTypeObject(this.type).prototype;
+      Object.setPrototypeOf(this, this.getTypeObject(this.type).prototype);
     }
 
     return clear;
@@ -130,7 +130,6 @@ PlacesItem.prototype = {
     return recordObj;
   },
 
-  __proto__: CryptoWrapper.prototype,
   _logName: "Sync.Record.PlacesItem",
 
   // Converts the record to a Sync bookmark object that can be passed to
@@ -162,6 +161,8 @@ PlacesItem.prototype = {
   },
 };
 
+Object.setPrototypeOf(PlacesItem.prototype, CryptoWrapper.prototype);
+
 Utils.deferGetSet(PlacesItem, "cleartext", [
   "hasDupe",
   "parentid",
@@ -174,7 +175,6 @@ function Bookmark(collection, id, type) {
   PlacesItem.call(this, collection, id, type || "bookmark");
 }
 Bookmark.prototype = {
-  __proto__: PlacesItem.prototype,
   _logName: "Sync.Record.Bookmark",
 
   toSyncBookmark() {
@@ -197,6 +197,8 @@ Bookmark.prototype = {
   },
 };
 
+Object.setPrototypeOf(Bookmark.prototype, PlacesItem.prototype);
+
 Utils.deferGetSet(Bookmark, "cleartext", [
   "title",
   "bmkUri",
@@ -209,7 +211,6 @@ function BookmarkQuery(collection, id) {
   Bookmark.call(this, collection, id, "query");
 }
 BookmarkQuery.prototype = {
-  __proto__: Bookmark.prototype,
   _logName: "Sync.Record.BookmarkQuery",
 
   toSyncBookmark() {
@@ -226,13 +227,14 @@ BookmarkQuery.prototype = {
   },
 };
 
+Object.setPrototypeOf(BookmarkQuery.prototype, Bookmark.prototype);
+
 Utils.deferGetSet(BookmarkQuery, "cleartext", ["folderName", "queryId"]);
 
 function BookmarkFolder(collection, id, type) {
   PlacesItem.call(this, collection, id, type || "folder");
 }
 BookmarkFolder.prototype = {
-  __proto__: PlacesItem.prototype,
   _logName: "Sync.Record.Folder",
 
   toSyncBookmark() {
@@ -250,6 +252,8 @@ BookmarkFolder.prototype = {
   },
 };
 
+Object.setPrototypeOf(BookmarkFolder.prototype, PlacesItem.prototype);
+
 Utils.deferGetSet(BookmarkFolder, "cleartext", [
   "description",
   "title",
@@ -260,7 +264,6 @@ function Livemark(collection, id) {
   BookmarkFolder.call(this, collection, id, "livemark");
 }
 Livemark.prototype = {
-  __proto__: BookmarkFolder.prototype,
   _logName: "Sync.Record.Livemark",
 
   toSyncBookmark() {
@@ -279,13 +282,14 @@ Livemark.prototype = {
   },
 };
 
+Object.setPrototypeOf(Livemark.prototype, BookmarkFolder.prototype);
+
 Utils.deferGetSet(Livemark, "cleartext", ["siteUri", "feedUri"]);
 
 function BookmarkSeparator(collection, id) {
   PlacesItem.call(this, collection, id, "separator");
 }
 BookmarkSeparator.prototype = {
-  __proto__: PlacesItem.prototype,
   _logName: "Sync.Record.Separator",
 
   fromSyncBookmark(item) {
@@ -294,6 +298,8 @@ BookmarkSeparator.prototype = {
   },
 };
 
+Object.setPrototypeOf(BookmarkSeparator.prototype, PlacesItem.prototype);
+
 Utils.deferGetSet(BookmarkSeparator, "cleartext", "pos");
 
 /**
@@ -306,7 +312,6 @@ function BookmarksEngine(service) {
   SyncEngine.call(this, "Bookmarks", service);
 }
 BookmarksEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _recordObj: PlacesItem,
   _trackerObj: BookmarksTracker,
   _storeObj: BookmarksStore,
@@ -628,6 +633,8 @@ BookmarksEngine.prototype = {
   },
 };
 
+Object.setPrototypeOf(BookmarksEngine.prototype, SyncEngine.prototype);
+
 /**
  * The bookmarks store delegates to the mirror for staging and applying
  * records. Most `Store` methods intentionally remain abstract, so you can't use
@@ -639,8 +646,6 @@ function BookmarksStore(name, engine) {
 }
 
 BookmarksStore.prototype = {
-  __proto__: Store.prototype,
-
   _openMirrorPromise: null,
 
   // For tests.
@@ -787,6 +792,8 @@ BookmarksStore.prototype = {
   },
 };
 
+Object.setPrototypeOf(BookmarksStore.prototype, Store.prototype);
+
 // The bookmarks tracker is a special flower. Instead of listening for changes
 // via observer notifications, it queries Places for the set of items that have
 // changed since the last sync. Because it's a "pull-based" tracker, it ignores
@@ -796,8 +803,6 @@ function BookmarksTracker(name, engine) {
   Tracker.call(this, name, engine);
 }
 BookmarksTracker.prototype = {
-  __proto__: Tracker.prototype,
-
   onStart() {
     lazy.PlacesUtils.bookmarks.addObserver(this, true);
     this._placesListener = new PlacesWeakCallbackWrapper(
@@ -941,6 +946,8 @@ BookmarksTracker.prototype = {
   },
 };
 
+Object.setPrototypeOf(BookmarksTracker.prototype, Tracker.prototype);
+
 /**
  * A changeset that stores extra metadata in a change record for each ID. The
  * engine updates this metadata when uploading Sync records, and writes it back

services/sync/modules/engines/clients.js

@@ -88,10 +88,10 @@ function ClientsRec(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
 ClientsRec.prototype = {
-  __proto__: CryptoWrapper.prototype,
   _logName: "Sync.Record.Clients",
   ttl: CLIENTS_TTL,
 };
+Object.setPrototypeOf(ClientsRec.prototype, CryptoWrapper.prototype);
 
 Utils.deferGetSet(ClientsRec, "cleartext", [
   "name",
@@ -115,7 +115,6 @@ function ClientEngine(service) {
   Utils.defineLazyIDProperty(this, "localID", "services.sync.client.GUID");
 }
 ClientEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: ClientStore,
   _recordObj: ClientsRec,
   _trackerObj: ClientsTracker,
@@ -949,13 +948,12 @@ ClientEngine.prototype = {
     this._modified.delete(id);
   },
 };
+Object.setPrototypeOf(ClientEngine.prototype, SyncEngine.prototype);
 
 function ClientStore(name, engine) {
   Store.call(this, name, engine);
 }
 ClientStore.prototype = {
-  __proto__: Store.prototype,
-
   _remoteClients: {},
 
   async create(record) {
@@ -1088,13 +1086,12 @@ ClientStore.prototype = {
     this._remoteClients = {};
   },
 };
+Object.setPrototypeOf(ClientStore.prototype, Store.prototype);
 
 function ClientsTracker(name, engine) {
   LegacyTracker.call(this, name, engine);
 }
 ClientsTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-
   _enabled: false,
 
   onStart() {
@@ -1124,3 +1121,4 @@ ClientsTracker.prototype = {
     }
   },
 };
+Object.setPrototypeOf(ClientsTracker.prototype, LegacyTracker.prototype);

services/sync/modules/engines/extension-storage.js

@@ -87,7 +87,6 @@ function ExtensionStorageEngineBridge(service) {
 }
 
 ExtensionStorageEngineBridge.prototype = {
-  __proto__: BridgedEngine.prototype,
   syncPriority: 10,
 
   // Used to override the engine name in telemetry, so that we can distinguish .
@@ -185,6 +184,10 @@ ExtensionStorageEngineBridge.prototype = {
     setEngineEnabled(enabled);
   },
 };
+Object.setPrototypeOf(
+  ExtensionStorageEngineBridge.prototype,
+  BridgedEngine.prototype
+);
 
 /**
  *****************************************************************************
@@ -212,7 +215,6 @@ function ExtensionStorageEngineKinto(service) {
   );
 }
 ExtensionStorageEngineKinto.prototype = {
-  __proto__: SyncEngine.prototype,
   _trackerObj: ExtensionStorageTracker,
   // we don't need these since we implement our own sync logic
   _storeObj: undefined,
@@ -266,14 +268,16 @@ ExtensionStorageEngineKinto.prototype = {
     return shouldSkip;
   },
 };
+Object.setPrototypeOf(
+  ExtensionStorageEngineKinto.prototype,
+  SyncEngine.prototype
+);
 
 function ExtensionStorageTracker(name, engine) {
   Tracker.call(this, name, engine);
   this._ignoreAll = false;
 }
 ExtensionStorageTracker.prototype = {
-  __proto__: Tracker.prototype,
-
   get ignoreAll() {
     return this._ignoreAll;
   },
@@ -304,3 +308,4 @@ ExtensionStorageTracker.prototype = {
     this.score += lazy.SCORE_INCREMENT_MEDIUM;
   },
 };
+Object.setPrototypeOf(ExtensionStorageTracker.prototype, Tracker.prototype);

services/sync/modules/engines/forms.js

@@ -32,10 +32,10 @@ function FormRec(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
 FormRec.prototype = {
-  __proto__: CryptoWrapper.prototype,
   _logName: "Sync.Record.Form",
   ttl: FORMS_TTL,
 };
+Object.setPrototypeOf(FormRec.prototype, CryptoWrapper.prototype);
 
 Utils.deferGetSet(FormRec, "cleartext", ["name", "value"]);
 
@@ -91,7 +91,6 @@ function FormEngine(service) {
   SyncEngine.call(this, "Forms", service);
 }
 FormEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: FormStore,
   _trackerObj: FormTracker,
   _recordObj: FormRec,
@@ -106,13 +105,12 @@ FormEngine.prototype = {
     return FormWrapper.getGUID(item.name, item.value);
   },
 };
+Object.setPrototypeOf(FormEngine.prototype, SyncEngine.prototype);
 
 function FormStore(name, engine) {
   Store.call(this, name, engine);
 }
 FormStore.prototype = {
-  __proto__: Store.prototype,
-
   async _processChange(change) {
     // If this._changes is defined, then we are applying a batch, so we
     // can defer it.
@@ -197,13 +195,12 @@ FormStore.prototype = {
     await FormWrapper._update(change);
   },
 };
+Object.setPrototypeOf(FormStore.prototype, Store.prototype);
 
 function FormTracker(name, engine) {
   LegacyTracker.call(this, name, engine);
 }
 FormTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-
   QueryInterface: ChromeUtils.generateQI([
     "nsIObserver",
     "nsISupportsWeakReference",
@@ -238,6 +235,7 @@ FormTracker.prototype = {
     }
   },
 };
+Object.setPrototypeOf(FormTracker.prototype, LegacyTracker.prototype);
 
 class FormsProblemData extends CollectionProblemData {
   getSummary() {

services/sync/modules/engines/history.js

@@ -36,10 +36,10 @@ function HistoryRec(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
 HistoryRec.prototype = {
-  __proto__: CryptoWrapper.prototype,
   _logName: "Sync.Record.History",
   ttl: HISTORY_TTL,
 };
+Object.setPrototypeOf(HistoryRec.prototype, CryptoWrapper.prototype);
 
 Utils.deferGetSet(HistoryRec, "cleartext", ["histUri", "title", "visits"]);
 
@@ -47,7 +47,6 @@ function HistoryEngine(service) {
   SyncEngine.call(this, "History", service);
 }
 HistoryEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _recordObj: HistoryRec,
   _storeObj: HistoryStore,
   _trackerObj: HistoryTracker,
@@ -115,14 +114,13 @@ HistoryEngine.prototype = {
     await lazy.PlacesSyncUtils.history.reset();
   },
 };
+Object.setPrototypeOf(HistoryEngine.prototype, SyncEngine.prototype);
 
 function HistoryStore(name, engine) {
   Store.call(this, name, engine);
 }
 
 HistoryStore.prototype = {
-  __proto__: Store.prototype,
-
   // We try and only update this many visits at one time.
   MAX_VISITS_PER_INSERT: 500,
 
@@ -499,13 +497,12 @@ HistoryStore.prototype = {
     return lazy.PlacesSyncUtils.history.wipe();
   },
 };
+Object.setPrototypeOf(HistoryStore.prototype, Store.prototype);
 
 function HistoryTracker(name, engine) {
   LegacyTracker.call(this, name, engine);
 }
 HistoryTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-
   onStart() {
     this._log.info("Adding Places observer.");
     this._placesObserver = new PlacesWeakCallbackWrapper(
@@ -582,3 +579,4 @@ HistoryTracker.prototype = {
     }
   },
 };
+Object.setPrototypeOf(HistoryTracker.prototype, LegacyTracker.prototype);

services/sync/modules/engines/passwords.js

@@ -54,7 +54,6 @@ function LoginRec(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
 LoginRec.prototype = {
-  __proto__: CryptoWrapper.prototype,
   _logName: "Sync.Record.Login",
 
   cleartextToString() {
@@ -65,6 +64,7 @@ LoginRec.prototype = {
     return JSON.stringify(o);
   },
 };
+Object.setPrototypeOf(LoginRec.prototype, CryptoWrapper.prototype);
 
 Utils.deferGetSet(LoginRec, "cleartext", [
   "hostname",
@@ -82,7 +82,6 @@ function PasswordEngine(service) {
   SyncEngine.call(this, "Passwords", service);
 }
 PasswordEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: PasswordStore,
   _trackerObj: PasswordTracker,
   _recordObj: LoginRec,
@@ -185,6 +184,7 @@ PasswordEngine.prototype = {
     return new PasswordValidator();
   },
 };
+Object.setPrototypeOf(PasswordEngine.prototype, SyncEngine.prototype);
 
 function PasswordStore(name, engine) {
   Store.call(this, name, engine);
@@ -195,8 +195,6 @@ function PasswordStore(name, engine) {
   );
 }
 PasswordStore.prototype = {
-  __proto__: Store.prototype,
-
   _newPropertyBag() {
     return Cc["@mozilla.org/hash-property-bag;1"].createInstance(
       Ci.nsIWritablePropertyBag2
@@ -382,13 +380,12 @@ PasswordStore.prototype = {
     Services.logins.removeAllUserFacingLogins();
   },
 };
+Object.setPrototypeOf(PasswordStore.prototype, Store.prototype);
 
 function PasswordTracker(name, engine) {
   LegacyTracker.call(this, name, engine);
 }
 PasswordTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-
   onStart() {
     Svc.Obs.add("passwordmgr-storage-changed", this.asyncObserver);
   },
@@ -461,6 +458,7 @@ PasswordTracker.prototype = {
     return true;
   },
 };
+Object.setPrototypeOf(PasswordTracker.prototype, LegacyTracker.prototype);
 
 class PasswordValidator extends CollectionValidator {
   constructor() {

services/sync/modules/engines/prefs.js

@@ -108,9 +108,9 @@ function PrefRec(collection, id) {
   CryptoWrapper.call(this, collection, id);
 }
 PrefRec.prototype = {
-  __proto__: CryptoWrapper.prototype,
   _logName: "Sync.Record.Pref",
 };
+Object.setPrototypeOf(PrefRec.prototype, CryptoWrapper.prototype);
 
 Utils.deferGetSet(PrefRec, "cleartext", ["value"]);
 
@@ -118,7 +118,6 @@ function PrefsEngine(service) {
   SyncEngine.call(this, "Prefs", service);
 }
 PrefsEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: PrefStore,
   _trackerObj: PrefTracker,
   _recordObj: PrefRec,
@@ -156,6 +155,7 @@ PrefsEngine.prototype = {
     }
   },
 };
+Object.setPrototypeOf(PrefsEngine.prototype, SyncEngine.prototype);
 
 // We don't use services.sync.engine.tabs.filteredSchemes since it includes
 // about: pages and the like, which we want to be syncable in preferences.
@@ -181,8 +181,6 @@ function PrefStore(name, engine) {
   );
 }
 PrefStore.prototype = {
-  __proto__: Store.prototype,
-
   __prefs: null,
   get _prefs() {
     if (!this.__prefs) {
@@ -404,6 +402,7 @@ PrefStore.prototype = {
     this._log.trace("Ignoring wipe request");
   },
 };
+Object.setPrototypeOf(PrefStore.prototype, Store.prototype);
 
 function PrefTracker(name, engine) {
   Tracker.call(this, name, engine);
@@ -411,8 +410,6 @@ function PrefTracker(name, engine) {
   Svc.Obs.add("profile-before-change", this.asyncObserver);
 }
 PrefTracker.prototype = {
-  __proto__: Tracker.prototype,
-
   get ignoreAll() {
     return this._ignoreAll;
   },
@@ -472,6 +469,7 @@ PrefTracker.prototype = {
     }
   },
 };
+Object.setPrototypeOf(PrefTracker.prototype, Tracker.prototype);
 
 function getPrefsGUIDForTest() {
   return lazy.PREFS_GUID;

services/sync/modules/engines/tabs.js

@@ -78,7 +78,6 @@ function TabEngine(service) {
 }
 
 TabEngine.prototype = {
-  __proto__: BridgedEngine.prototype,
   _trackerObj: TabTracker,
   syncPriority: 3,
 
@@ -342,6 +341,7 @@ TabEngine.prototype = {
     }
   },
 };
+Object.setPrototypeOf(TabEngine.prototype, BridgedEngine.prototype);
 
 const TabProvider = {
   getWindowEnumerator() {
@@ -425,8 +425,6 @@ function TabTracker(name, engine) {
   this._unregisterListeners = Utils.bind2(this, this._unregisterListeners);
 }
 TabTracker.prototype = {
-  __proto__: Tracker.prototype,
-
   QueryInterface: ChromeUtils.generateQI(["nsIObserver"]),
 
   clearChangedIDs() {
@@ -609,3 +607,4 @@ TabTracker.prototype = {
     }
   },
 };
+Object.setPrototypeOf(TabTracker.prototype, Tracker.prototype);

services/sync/modules/keys.js

@@ -132,8 +132,6 @@ BulkKeyBundle.fromJWK = function(jwk) {
 };
 
 BulkKeyBundle.prototype = {
-  __proto__: KeyBundle.prototype,
-
   get collection() {
     return this._collection;
   },
@@ -171,3 +169,5 @@ BulkKeyBundle.prototype = {
     this.hmacKey = CommonUtils.safeAtoB(value[1]);
   },
 };
+
+Object.setPrototypeOf(BulkKeyBundle.prototype, KeyBundle.prototype);

services/sync/modules/record.js

@@ -175,7 +175,6 @@ function RawCryptoWrapper(collection, id) {
   this.ciphertext = null;
 }
 RawCryptoWrapper.prototype = {
-  __proto__: WBORecord.prototype,
   _logName: "Sync.Record.RawCryptoWrapper",
 
   /**
@@ -280,6 +279,8 @@ RawCryptoWrapper.prototype = {
   },
 };
 
+Object.setPrototypeOf(RawCryptoWrapper.prototype, WBORecord.prototype);
+
 Utils.deferGetSet(RawCryptoWrapper, "payload", ["ciphertext", "IV", "hmac"]);
 
 /**
@@ -294,7 +295,6 @@ function CryptoWrapper(collection, id) {
   RawCryptoWrapper.call(this, collection, id);
 }
 CryptoWrapper.prototype = {
-  __proto__: RawCryptoWrapper.prototype,
   _logName: "Sync.Record.CryptoWrapper",
 
   defaultCleartext() {
@@ -365,6 +365,8 @@ CryptoWrapper.prototype = {
   },
 };
 
+Object.setPrototypeOf(CryptoWrapper.prototype, RawCryptoWrapper.prototype);
+
 Utils.deferGetSet(CryptoWrapper, "cleartext", "deleted");
 
 /**
@@ -779,7 +781,6 @@ function Collection(uri, recordObj, service) {
   this._offset = null;
 }
 Collection.prototype = {
-  __proto__: Resource.prototype,
   _logName: "Sync.Collection",
 
   _rebuildURL: function Coll__rebuildURL() {
@@ -1010,6 +1011,8 @@ Collection.prototype = {
   },
 };
 
+Object.setPrototypeOf(Collection.prototype, Resource.prototype);
+
 // These are limits for requests provided by the server at the
 // info/configuration endpoint -- server documentation is available here:
 // http://moz-services-docs.readthedocs.io/en/latest/storage/apis-1.5.html#api-instructions

services/sync/tests/unit/head_errorhandler_common.js

@@ -161,7 +161,6 @@ const EHTestsCommon = {
       SyncEngine.call(this, "Catapult", Service);
     }
     CatapultEngine.prototype = {
-      __proto__: SyncEngine.prototype,
       exception: null, // tests fill this in
       async _sync() {
         if (this.exception) {
@@ -169,6 +168,7 @@ const EHTestsCommon = {
         }
       },
     };
+    Object.setPrototypeOf(CatapultEngine.prototype, SyncEngine.prototype);
 
     return CatapultEngine;
   })(),

services/sync/tests/unit/head_http_server.js

@@ -704,7 +704,7 @@ var SyncServerCallback = {
  * SyncServerCallback) as input.
  */
 function SyncServer(callback) {
-  this.callback = callback || { __proto__: SyncServerCallback };
+  this.callback = callback || Object.create(SyncServerCallback);
   this.server = new HttpServer();
   this.started = false;
   this.users = {};

services/sync/tests/unit/test_addon_utils.js

@@ -119,10 +119,13 @@ add_task(async function test_source_uri_rewrite() {
   // skewed.
 
   // We resort to monkeypatching because of the API design.
-  let oldFunction = AddonUtils.__proto__.installAddonFromSearchResult;
+  let oldFunction = Object.getPrototypeOf(AddonUtils)
+    .installAddonFromSearchResult;
 
   let installCalled = false;
-  AddonUtils.__proto__.installAddonFromSearchResult = async function testInstallAddon(
+  Object.getPrototypeOf(
+    AddonUtils
+  ).installAddonFromSearchResult = async function testInstallAddon(
     addon,
     metadata
   ) {
@@ -156,7 +159,7 @@ add_task(async function test_source_uri_rewrite() {
   await AddonUtils.installAddons([installOptions]);
 
   Assert.ok(installCalled);
-  AddonUtils.__proto__.installAddonFromSearchResult = oldFunction;
+  Object.getPrototypeOf(AddonUtils).installAddonFromSearchResult = oldFunction;
 
   await promiseStopServer(server);
 });

services/sync/tests/unit/test_clients_engine.js

@@ -76,7 +76,6 @@ add_task(async function test_bad_hmac() {
   let deletedCollections = [];
   let deletedItems = [];
   let callback = {
-    __proto__: SyncServerCallback,
     onItemDeleted(username, coll, wboID) {
       deletedItems.push(coll + "/" + wboID);
     },
@@ -84,6 +83,7 @@ add_task(async function test_bad_hmac() {
       deletedCollections.push(coll);
     },
   };
+  Object.setPrototypeOf(callback, SyncServerCallback);
   let server = await serverForFoo(engine, callback);
   let user = server.user("foo");
 

services/sync/tests/unit/test_declined.js

@@ -22,7 +22,8 @@ function DummyEngine() {}
 DummyEngine.prototype.name = "dummy";
 
 function ActualEngine() {}
-ActualEngine.prototype = { __proto__: SyncEngine.prototype, name: "actual" };
+ActualEngine.prototype.name = "actual";
+Object.setPrototypeOf(ActualEngine.prototype, SyncEngine.prototype);
 
 function getEngineManager() {
   let manager = new EngineManager(Service);

services/sync/tests/unit/test_engine.js

@@ -14,19 +14,16 @@ function SteamStore(engine) {
   this.wasWiped = false;
 }
 SteamStore.prototype = {
-  __proto__: Store.prototype,
-
   async wipe() {
     this.wasWiped = true;
   },
 };
+Object.setPrototypeOf(SteamStore.prototype, Store.prototype);
 
 function SteamTracker(name, engine) {
   LegacyTracker.call(this, name || "Steam", engine);
 }
-SteamTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-};
+Object.setPrototypeOf(SteamTracker.prototype, LegacyTracker.prototype);
 
 function SteamEngine(name, service) {
   SyncEngine.call(this, name, service);
@@ -34,7 +31,6 @@ function SteamEngine(name, service) {
   this.wasSynced = false;
 }
 SteamEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: SteamStore,
   _trackerObj: SteamTracker,
 
@@ -46,6 +42,7 @@ SteamEngine.prototype = {
     this.wasSynced = true;
   },
 };
+Object.setPrototypeOf(SteamEngine.prototype, SyncEngine.prototype);
 
 var engineObserver = {
   topics: [],

services/sync/tests/unit/test_errorhandler_sync_checkServerError.js

@@ -13,12 +13,12 @@ function CatapultEngine() {
   SyncEngine.call(this, "Catapult", Service);
 }
 CatapultEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   exception: null, // tests fill this in
   async _sync() {
     throw this.exception;
   },
 };
+Object.setPrototypeOf(CatapultEngine.prototype, SyncEngine.prototype);
 
 async function sync_httpd_setup() {
   let collectionsHelper = track_collections_helper();

services/sync/tests/unit/test_extension_storage_engine_kinto.js

@@ -21,12 +21,13 @@ function mock(options) {
     calls.push(arguments);
     return options.returns;
   };
-  Object.setPrototypeOf(ret, {
-    __proto__: Function.prototype,
+  let proto = {
     get calls() {
       return calls;
     },
-  });
+  };
+  Object.setPrototypeOf(proto, Function.prototype);
+  Object.setPrototypeOf(ret, proto);
   return ret;
 }
 

services/sync/tests/unit/test_fxa_node_reassignment.js

@@ -45,7 +45,6 @@ function prepareServer(cbAfterTokenFetch) {
   // A server callback to ensure we don't accidentally hit the wrong endpoint
   // after a node reassignment.
   let callback = {
-    __proto__: SyncServerCallback,
     onRequest(req, resp) {
       let full = `${req.scheme}://${req.host}:${req.port}${req.path}`;
       let expected = config.fxaccount.token.endpoint;
@@ -55,6 +54,7 @@ function prepareServer(cbAfterTokenFetch) {
       );
     },
   };
+  Object.setPrototypeOf(callback, SyncServerCallback);
   let server = new SyncServer(callback);
   server.registerUser("johndoe");
   server.start();

services/sync/tests/unit/test_httpd_sync_server.js

@@ -3,9 +3,7 @@
 
 add_test(function test_creation() {
   // Explicit callback for this one.
-  let server = new SyncServer({
-    __proto__: SyncServerCallback,
-  });
+  let server = new SyncServer(Object.create(SyncServerCallback));
   Assert.ok(!!server); // Just so we have a check.
   server.start(null, function() {
     _("Started on " + server.port);
@@ -83,9 +81,7 @@ add_task(async function test_basic_http() {
 });
 
 add_task(async function test_info_collections() {
-  let server = new SyncServer({
-    __proto__: SyncServerCallback,
-  });
+  let server = new SyncServer(Object.create(SyncServerCallback));
   function responseHasCorrectHeaders(r) {
     Assert.equal(r.status, 200);
     Assert.equal(r.headers["content-type"], "application/json");

services/sync/tests/unit/test_service_startOver.js

@@ -7,13 +7,12 @@ function BlaEngine() {
   SyncEngine.call(this, "Bla", Service);
 }
 BlaEngine.prototype = {
-  __proto__: SyncEngine.prototype,
-
   removed: false,
   async removeClientData() {
     this.removed = true;
   },
 };
+Object.setPrototypeOf(BlaEngine.prototype, SyncEngine.prototype);
 
 add_task(async function setup() {
   await Service.engineManager.register(BlaEngine);

services/sync/tests/unit/test_service_sync_specified.js

@@ -9,21 +9,21 @@ function SteamEngine() {
   SyncEngine.call(this, "Steam", Service);
 }
 SteamEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   async _sync() {
     syncedEngines.push(this.name);
   },
 };
+Object.setPrototypeOf(SteamEngine.prototype, SyncEngine.prototype);
 
 function StirlingEngine() {
   SyncEngine.call(this, "Stirling", Service);
 }
 StirlingEngine.prototype = {
-  __proto__: SteamEngine.prototype,
   async _sync() {
     syncedEngines.push(this.name);
   },
 };
+Object.setPrototypeOf(StirlingEngine.prototype, SteamEngine.prototype);
 
 // Tracking info/collections.
 var collectionsHelper = track_collections_helper();

services/sync/tests/unit/test_service_sync_updateEnabledEngines.js

@@ -20,7 +20,6 @@ function SteamEngine() {
   SyncEngine.call(this, "Steam", Service);
 }
 SteamEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   // We're not interested in engine sync but what the service does.
   _storeObj: QuietStore,
 
@@ -28,17 +27,18 @@ SteamEngine.prototype = {
     await this._syncStartup();
   },
 };
+Object.setPrototypeOf(SteamEngine.prototype, SyncEngine.prototype);
 
 function StirlingEngine() {
   SyncEngine.call(this, "Stirling", Service);
 }
 StirlingEngine.prototype = {
-  __proto__: SteamEngine.prototype,
   // This engine's enabled state is the same as the SteamEngine's.
   get prefName() {
     return "steam";
   },
 };
+Object.setPrototypeOf(StirlingEngine.prototype, SteamEngine.prototype);
 
 // Tracking info/collections.
 var collectionsHelper = track_collections_helper();

services/sync/tests/unit/test_service_wipeClient.js

@@ -7,8 +7,6 @@ function CanDecryptEngine() {
   SyncEngine.call(this, "CanDecrypt", Service);
 }
 CanDecryptEngine.prototype = {
-  __proto__: SyncEngine.prototype,
-
   // Override these methods with mocks for the test
   async canDecrypt() {
     return true;
@@ -19,13 +17,12 @@ CanDecryptEngine.prototype = {
     this.wasWiped = true;
   },
 };
+Object.setPrototypeOf(CanDecryptEngine.prototype, SyncEngine.prototype);
 
 function CannotDecryptEngine() {
   SyncEngine.call(this, "CannotDecrypt", Service);
 }
 CannotDecryptEngine.prototype = {
-  __proto__: SyncEngine.prototype,
-
   // Override these methods with mocks for the test
   async canDecrypt() {
     return false;
@@ -36,6 +33,7 @@ CannotDecryptEngine.prototype = {
     this.wasWiped = true;
   },
 };
+Object.setPrototypeOf(CannotDecryptEngine.prototype, SyncEngine.prototype);
 
 let canDecryptEngine;
 let cannotDecryptEngine;

services/sync/tests/unit/test_sync_auth_manager.js

@@ -49,7 +49,6 @@ var MockFxAccountsClient = function() {
   FxAccountsClient.apply(this);
 };
 MockFxAccountsClient.prototype = {
-  __proto__: FxAccountsClient.prototype,
   accountStatus() {
     return Promise.resolve(true);
   },
@@ -64,6 +63,10 @@ MockFxAccountsClient.prototype = {
     });
   },
 };
+Object.setPrototypeOf(
+  MockFxAccountsClient.prototype,
+  FxAccountsClient.prototype
+);
 
 add_test(function test_initial_state() {
   _("Verify initial state");
@@ -150,7 +153,6 @@ add_task(async function test_initialializeWithAuthErrorAndDeletedAccount() {
     FxAccountsClient.apply(this);
   };
   AuthErrorMockFxAClient.prototype = {
-    __proto__: FxAccountsClient.prototype,
     accessTokenWithSessionToken() {
       accessTokenWithSessionTokenCalled = true;
       return Promise.reject({
@@ -167,6 +169,10 @@ add_task(async function test_initialializeWithAuthErrorAndDeletedAccount() {
       return Promise.resolve(false);
     },
   };
+  Object.setPrototypeOf(
+    AuthErrorMockFxAClient.prototype,
+    FxAccountsClient.prototype
+  );
 
   let mockFxAClient = new AuthErrorMockFxAClient();
   syncAuthManager._fxaService._internal._fxAccountsClient = mockFxAClient;
@@ -478,12 +484,15 @@ add_task(async function test_refreshAccessTokenOn401() {
     FxAccountsClient.apply(this);
   };
   CheckSignMockFxAClient.prototype = {
-    __proto__: FxAccountsClient.prototype,
     accessTokenWithSessionToken() {
       ++getTokenCount;
       return Promise.resolve({ access_token: "token" });
     },
   };
+  Object.setPrototypeOf(
+    CheckSignMockFxAClient.prototype,
+    FxAccountsClient.prototype
+  );
 
   let mockFxAClient = new CheckSignMockFxAClient();
   syncAuthManager._fxaService._internal._fxAccountsClient = mockFxAClient;

services/sync/tests/unit/test_syncscheduler.js

@@ -17,12 +17,12 @@ function CatapultEngine() {
   SyncEngine.call(this, "Catapult", Service);
 }
 CatapultEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   exception: null, // tests fill this in
   async _sync() {
     throw this.exception;
   },
 };
+Object.setPrototypeOf(CatapultEngine.prototype, SyncEngine.prototype);
 
 var scheduler = new SyncScheduler(Service);
 let clientsEngine;
@@ -192,7 +192,6 @@ add_task(async function test_sync_skipped_low_score_no_resync() {
   }
 
   SkipEngine.prototype = {
-    __proto__: SyncEngine.prototype,
     _sync() {
       do_throw("Should have been skipped");
     },
@@ -200,6 +199,7 @@ add_task(async function test_sync_skipped_low_score_no_resync() {
       return true;
     },
   };
+  Object.setPrototypeOf(SkipEngine.prototype, SyncEngine.prototype);
   await Service.engineManager.register(SkipEngine);
 
   let engine = Service.engineManager.get("skip");

services/sync/tests/unit/test_telemetry.js

@@ -15,25 +15,18 @@ const fxAccounts = getFxAccountsSingleton();
 function SteamStore(engine) {
   Store.call(this, "Steam", engine);
 }
-
-SteamStore.prototype = {
-  __proto__: Store.prototype,
-};
+Object.setPrototypeOf(SteamStore.prototype, Store.prototype);
 
 function SteamTracker(name, engine) {
   LegacyTracker.call(this, name || "Steam", engine);
 }
-
-SteamTracker.prototype = {
-  __proto__: LegacyTracker.prototype,
-};
+Object.setPrototypeOf(SteamTracker.prototype, LegacyTracker.prototype);
 
 function SteamEngine(service) {
   SyncEngine.call(this, "steam", service);
 }
 
 SteamEngine.prototype = {
-  __proto__: SyncEngine.prototype,
   _storeObj: SteamStore,
   _trackerObj: SteamTracker,
   _errToThrow: null,
@@ -47,6 +40,7 @@ SteamEngine.prototype = {
     return new SteamValidator();
   },
 };
+Object.setPrototypeOf(SteamEngine.prototype, SyncEngine.prototype);
 
 function BogusEngine(service) {
   SyncEngine.call(this, "bogus", service);

services/sync/tps/extensions/tps/resource/modules/bookmarks.jsm

@@ -37,7 +37,7 @@ async function DumpBookmarks() {
  * extend, causes a child object to inherit from a parent
  */
 function extend(child, supertype) {
-  child.prototype.__proto__ = supertype.prototype;
+  Object.setPrototypeOf(child.prototype, supertype.prototype);
 }
 /**
  * PlacesItemProps object, holds properties for places items