Make download.default_directory read only in settingsPrivate

Bug: 836362
Change-Id: I677cffed597ce6dc50247916055bd3182d4a206e
Reviewed-on: https://chromium-review.googlesource.com/1041567
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558802}
2 files changed