Add library 'six' to //third_party.

Modify scripts that indirectly use it to include the new location into
sys.path so that they are not implicitly using a copy of six that is
installed in the environment.

Bug: 1004616,1047519
Change-Id: I7d5054802a57744933f038ea0b58af8f7f4314a3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2043078
Reviewed-by: Nico Weber <thakis@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Tibor Goldschwendt <tiborg@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Chris Palmer <palmer@chromium.org>
Commit-Queue: Sajjad Mirza <sajjadm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#740455}
GitOrigin-RevId: 72e668371ae0e9b4ffb5372316d5e800504d0ccb
18 files changed
tree: bfa5f2ce1232e78f2a4eab739903eb9f6cf19bff
  1. LICENSE
  2. OWNERS
  3. README.chromium
  4. src/