chromeos: Switch to subprocess32 (instead of 42) in test runner.

In the beginning python was created. This has made a lot of people
very angry and been widely regarded as a bad move.

Bug: 1050466
Change-Id: Ieac7ca2a42cb21e78d77d628c3fb645d32b7625f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2047351
Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#740044}

.vpython

@@ -21,6 +21,9 @@
 #
 # Read more about `vpython` and how to modify this file here:
 #   https://chromium.googlesource.com/infra/infra/+/master/doc/users/vpython.md
+#
+# For the definition of this spec, see:
+#   https://chromium.googlesource.com/infra/luci/luci-go/+/master/vpython/api/vpython/spec.proto
 
 python_version: "2.7"
 
@@ -30,6 +33,19 @@ wheel: <
   name: "infra/python/wheels/jsonlines-py2_py3"
   version: "version:1.2.0"
 >
+wheel: <
+  name: "infra/python/wheels/subprocess32/${vpython_platform}"
+  version: "version:3.5.0rc1"
+  # Only download for linux since we shouldn't be running CrOS tests on mac/win.
+  match_tag: <
+    abi: "cp27mu"
+    platform: "manylinux1_i686"
+  >
+  match_tag: <
+    abi: "cp27mu"
+    platform: "manylinux1_x86_64"
+  >
+>
 
 # Used by:
 #   build/chromeos/test_runner.py

build/chromeos/test_runner.py

@@ -31,10 +31,7 @@
 from pylib.base import base_test_result  # pylint: disable=import-error
 from pylib.results import json_results  # pylint: disable=import-error
 
-# Use luci-py's subprocess42.py
-sys.path.insert(
-    0, os.path.join(CHROMIUM_SRC_PATH, 'tools', 'swarming_client', 'utils'))
-import subprocess42  # pylint: disable=import-error
+import subprocess32 as subprocess  # pylint: disable=import-error
 
 DEFAULT_CROS_CACHE = os.path.abspath(
     os.path.join(CHROMIUM_SRC_PATH, 'build', 'cros_cache'))
@@ -187,20 +184,20 @@ def _kill_child_procs(trapped_signal, _):
       logging.info('########################################')
       logging.info('Test attempt #%d', i)
       logging.info('########################################')
-      test_proc = subprocess42.Popen(
+      test_proc = subprocess.Popen(
           self._test_cmd,
           stdout=sys.stdout,
           stderr=sys.stderr,
           env=self._test_env)
       try:
         test_proc.wait(timeout=self._timeout)
-      except subprocess42.TimeoutExpired:
+      except subprocess.TimeoutExpired:
         logging.error('Test timed out. Sending SIGTERM.')
         # SIGTERM the proc and wait 10s for it to close.
         test_proc.terminate()
         try:
           test_proc.wait(timeout=10)
-        except subprocess42.TimeoutExpired:
+        except subprocess.TimeoutExpired:
           # If it hasn't closed in 10s, SIGKILL it.
           logging.error('Test did not exit in time. Sending SIGKILL.')
           test_proc.kill()
@@ -710,7 +707,7 @@ def host_cmd(args, unknown_args):
   logging.info('Running the following command:')
   logging.info(' '.join(cros_run_test_cmd))
 
-  return subprocess42.call(
+  return subprocess.call(
       cros_run_test_cmd, stdout=sys.stdout, stderr=sys.stderr, env=test_env)