Python 3 compatibility errors in third-party libraries

related CL: https://chromium-review.googlesource.com/c/v8/v8/+/1484302

Bug: chromium:935197
Change-Id: Iaabd72f3d11f4966b97c548e8f9b1bf222e9956e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1492335
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Sergiy Belozorov <sergiyb@chromium.org>
Reviewed-by: Johannes Henkel <johannes@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#637780}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: cb2e7e5a43149351308d8afedfb7247d55dd9dc1