- Pull in a trimmed down version of vs_toolchain.py from Chromium.
- Drop in toolchain_vs2013.hash from Chromium to use Chromium's
current toolchain.
- Add a very hacky vs_env.py to pull in Visual Studio. This is
loosely based off a handful of lines of Chromium's
tools/clang/scripts/update.py. This (and vs_toolchain.py) depends
on gyp which is now pulled in via DEPS.
BUG=430237
Change-Id: Ic29cbb15e19a99616cfe778d0778b9a71c45338a
Reviewed-on: https://boringssl-review.googlesource.com/3900
Reviewed-by: Adam Langley <agl@google.com>
