checkdeps: encode input to os.walk as utf-8.

Also fix checkdeps_test.py after the move into chromium/src.

Bug: 962059
Change-Id: I86f041e5ce819e0fbf3fb1e4de29fdde6c8d4596
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1610222
Auto-Submit: John Budorick <jbudorick@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#659173}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fd4b2b6305edc7ee5268a93136b55d44826b52aa
11 files changed