Fix a Python3-compatibility issue in get_toolchain_if_necessary.
Fix a Python3-compatibility issue in get_toolchain_if_necessary.

Bug: 1207012
Change-Id: I9205089c3a7d9f2d3e2eb9aac7ef6da9ae9b0876
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2890330
Commit-Queue: Dirk Pranke <6693ee08b084bb2ffa767f664c99b689395e0e4b@google.com>
Reviewed-by: Bruce Dawson <fe9e26f3989304bf7275ed139c57fd059c63d22d@chromium.org>

CoherentLabs/depot_tools,CoherentLabs/depot_tools