Add vpython3 to DEPS

Bug: chromium:1266833
Change-Id: I3ec80560881c596c41df389c754a5b01f911bb9a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3260516
Auto-Submit: Nico Hartmann <nicohartmann@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77742}

.vpython3

+# This is a vpython "spec" file.
+#
+# It describes patterns for python wheel dependencies of the python scripts in
+# the chromium repo, particularly for dependencies that have compiled components
+# (since pure-python dependencies can be easily vendored into third_party).
+#
+# When vpython is invoked, it finds this file and builds a python VirtualEnv,
+# containing all of the dependencies described in this file, fetching them from
+# CIPD (the "Chrome Infrastructure Package Deployer" service). Unlike `pip`,
+# this never requires the end-user machine to have a working python extension
+# compilation environment. All of these packages are built using:
+#   https://chromium.googlesource.com/infra/infra/+/main/infra/tools/dockerbuild/
+#
+# All python scripts in the repo share this same spec, to avoid dependency
+# fragmentation.
+#
+# If you have depot_tools installed in your $PATH, you can invoke python scripts
+# in this repo by running them as you normally would run them, except
+# substituting `vpython` instead of `python` on the command line, e.g.:
+#   vpython path/to/script.py some --arguments
+#
+# Read more about `vpython` and how to modify this file here:
+#   https://chromium.googlesource.com/infra/infra/+/main/doc/users/vpython.md
+
+python_version: "3.8"
+
+# The default set of platforms vpython checks does not yet include mac-arm64.
+# Setting `verify_pep425_tag` to the list of platforms we explicitly must support
+# allows us to ensure that vpython specs stay mac-arm64-friendly
+verify_pep425_tag: [
+    {python: "cp38", abi: "cp38", platform: "manylinux1_x86_64"},
+    {python: "cp38", abi: "cp38", platform: "linux_arm64"},
+
+    {python: "cp38", abi: "cp38", platform: "macosx_10_10_intel"},
+    {python: "cp38", abi: "cp38", platform: "macosx_11_0_arm64"},
+
+    {python: "cp38", abi: "cp38", platform: "win32"},
+    {python: "cp38", abi: "cp38", platform: "win_amd64"}
+]
+
+# TODO(https://crbug.com/898348): Add in necessary wheels as Python3 versions
+# become available.
+wheel: <
+  name: "infra/python/wheels/six-py2_py3"
+  version: "version:1.15.0"
+>

DEPS

@@ -584,6 +584,14 @@ hooks = [
                 '-vpython-tool', 'install',
     ],
   },
+  {
+    'name': 'vpython3_common',
+    'pattern': '.',
+    'action': [ 'vpython3',
+                '-vpython-spec', '.vpython3',
+                '-vpython-tool', 'install',
+    ],
+  },
   {
     'name': 'check_v8_header_includes',
     'pattern': '.',

OWNERS

@@ -12,6 +12,7 @@ per-file .gitignore=file:INFRA_OWNERS
 per-file .gn=file:INFRA_OWNERS
 per-file .mailmap=file:COMMON_OWNERS
 per-file .vpython=file:INFRA_OWNERS
+per-file .vpython3=file:INFRA_OWNERS
 per-file .ycm_extra_conf.py=file:INFRA_OWNERS
 per-file .bazelrc=file:COMMON_OWNERS
 per-file BUILD.bazel=file:COMMON_OWNERS