Private tabs with Tor enabled write cookies to disk

[riastradh-brave]

Steps to reproduce:

1. Open a private tab with Tor enabled.
2. Go to https://arxiv.org/help/submit

% echo .dump | sqlite3 ~/.config/brave-development/Partitions/tor/Cookies
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE meta(key LONGVARCHAR NOT NULL UNIQUE PRIMARY KEY, value LONGVARCHAR);
INSERT INTO meta VALUES('mmap_status','-1');
INSERT INTO meta VALUES('version','10');
INSERT INTO meta VALUES('last_compatible_version','5');
CREATE TABLE cookies (creation_utc INTEGER NOT NULL,host_key TEXT NOT NULL,name TEXT NOT NULL,value TEXT NOT NULL,path TEXT NOT NULL,expires_utc INTEGER NOT NULL,is_secure INTEGER NOT NULL,is_httponly INTEGER NOT NULL,last_access_utc INTEGER NOT NULL, has_expires INTEGER NOT NULL DEFAULT 1, is_persistent INTEGER NOT NULL DEFAULT 1,priority INTEGER NOT NULL DEFAULT 1,encrypted_value BLOB DEFAULT '',firstpartyonly INTEGER NOT NULL DEFAULT 0,UNIQUE (host_key, name, path));
INSERT INTO cookies VALUES(13173391188612624,'.arxiv.org','browser','','/',14119471188612624,0,0,13173391188612624,1,1,1,X'763131a367902c7b76d67c57f98c26c6eba598b588841f1f1fe3adf72aee7a7dc70df9',0);
COMMIT;

The cookie should not be there.

• Electron version: 6.0.11
• Operating system: Ubuntu 17.10

[riastradh-brave]

Fixed in 96c2eb7.