Delete Import.IncludesPasswords.Firefox histogram.

The password manager team doesn't look at it.

Bug: 975214
Change-Id: I96117b5e082f70a4b2860ba17ce02737b57a58ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1664146
Auto-Submit: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#670112}
2 files changed