We recently moved many files in third_party/WebKit to
third_party/blink. DEFAULT_BLACK_LIST should not block third_party/blink
as well as third_party/WebKit.

Bug: 836555
Change-Id: I5b3a3187f976b011c8efc8bf60635d6a5af1b56b
Reviewed-on: https://chromium-review.googlesource.com/1029562Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>