The Tor Browser: js/src/builtin/Set.js@129ffea94266

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

     1 /* This Source Code Form is subject to the terms of the Mozilla Public

     2  * License, v. 2.0. If a copy of the MPL was not distributed with this

     3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     5 /* ES6 20121122 draft 15.16.4.6. */

     7 function SetForEach(callbackfn, thisArg = undefined) {

     8     /* Step 1-2. */

     9     var S = this;

    10     if (!IsObject(S))

    11         ThrowError(JSMSG_BAD_TYPE, typeof S);

    13     /* Step 3-4. */

    14     try {

    15         callFunction(std_Set_has, S);

    16     } catch (e) {

    17         ThrowError(JSMSG_BAD_TYPE, typeof S);

    18     }

    20     /* Step 5-6. */

    21     if (!IsCallable(callbackfn))

    22         ThrowError(JSMSG_NOT_FUNCTION, DecompileArg(0, callbackfn));

    24     /* Step 7-8. */

    25     var values = callFunction(std_Set_iterator, S);

    26     while (true) {

    27         var result = callFunction(std_Set_iterator_next, values);

    28         if (result.done)

    29             break;

    30         var value = result.value;

    31         callFunction(callbackfn, thisArg, value, value, S);

    32     }

    33 }

The Tor Browser / file revision

js/src/builtin/Set.js@129ffea94266

js/src/builtin/Set.js