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- enable cookie encryption by default (use --disable-cookie-encryption to turn it off);
- configure OSCrypt iff cookie encryption is enabled and profile path is set
    (there was a bug there, but it was masked by cookie encryption being disabled);
- properly configure SSL channel id storage;
- use mock keychain on MacOSX

Bug: 864744
Change-Id: Ice97864bb80d8988e3e090310b35c509031a8e7d
Reviewed-on: https://chromium-review.googlesource.com/c/1274199Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599696}