Adding 'python' and vpython for Windows to run run-swarmed.py

run-swarmed.py was failing on Windows for two reasons:
1. Windows expects 'python' before calling a python script
2. Tasks on Windows Swarming bots are invoked via vpython, which isn't
   installed by default on them.

This change adds 'python' to the list of arguments for any subprocess,
and adds includes vpython with the isolates uploaded to Swarming
via --cipd-package and --env-prefix args when the target OS is Windows.

Bug: 1013382
Change-Id: I9b8edf9ebc2341cb72f8034ccec044f951745496
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854462
Commit-Queue: Mario Bianucci <mabian@microsoft.com>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705096}

tools/run-swarmed.py

@@ -46,7 +46,7 @@ def _Spawn(args):
   """
   index, args, isolated_hash = args
   json_file = os.path.join(args.results, '%d.json' % index)
-  trigger_args = [
+  trigger_args = [sys.executable,
       'tools/swarming_client/swarming.py', 'trigger',
       '-S', 'https://chromium-swarm.appspot.com',
       '-I', 'https://isolateserver.appspot.com',
@@ -62,7 +62,9 @@ def _Spawn(args):
       '-d', 'gpu', 'none',
       '-d', 'cpu', args.arch,
     ]
-  elif args.target_os == 'android':
+  elif args.target_os == 'android' or args.target_os == 'win':
+    if args.target_os == 'android':
+      trigger_args += ['-d', 'device_os', args.device_os]
     # The canonical version numbers are stored in the infra repository here:
     # build/scripts/slave/recipe_modules/swarming/api.py
     cpython_version = 'version:2.7.15.chromium14'
@@ -77,7 +79,6 @@ def _Spawn(args):
         '.swarming_module:infra/tools/luci/vpython/${platform}:' +
         vpython_version)
     trigger_args += [
-        '-d', 'device_os', args.device_os,
         '--cipd-package', cpython_pkg,
         '--cipd-package', vpython_native_pkg,
         '--cipd-package', vpython_pkg,
@@ -104,7 +105,7 @@ def _Spawn(args):
 
 def _Collect(spawn_result):
   index, json_file, args = spawn_result
-  p = subprocess.Popen([
+  p = subprocess.Popen([sys.executable,
     'tools/swarming_client/swarming.py', 'collect',
     '-S', 'https://chromium-swarm.appspot.com',
     '--json', json_file,
@@ -177,8 +178,8 @@ def main():
     else:
       args.arch = 'x86-64'
 
-  subprocess.check_call(
-      ['tools/mb/mb.py', 'isolate', '//' + args.out_dir, args.target_name])
+  subprocess.check_call([sys.executable, 'tools/mb/mb.py',
+      'isolate', '//' + args.out_dir, args.target_name])
 
   print('If you get authentication errors, follow:')
   print(
@@ -187,7 +188,7 @@ def main():
 
   print('Uploading to isolate server, this can take a while...')
   archive_output = subprocess.check_output(
-      ['tools/swarming_client/isolate.py', 'archive',
+      [sys.executable,'tools/swarming_client/isolate.py', 'archive',
        '-I', 'https://isolateserver.appspot.com',
        '-i', os.path.join(args.out_dir, args.target_name + '.isolate'),
        '-s', os.path.join(args.out_dir, args.target_name + '.isolated')])