[Translate] Clear recent target language in TranslatePrefs::ResetToDefaults

Bug: 939825
Change-Id: Ic3a6a94d619b1aa04ec69863c2af19190dd6b13a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1511914
Commit-Queue: Moe Ahmadi <mahmadi@chromium.org>
Commit-Queue: anthonyvd <anthonyvd@chromium.org>
Auto-Submit: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: anthonyvd <anthonyvd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#639096}
1 file changed