trigger.py: Append user tag.

scripts/trigger.py

@@ -11,6 +11,7 @@ import argparse
 import hashlib
 import logging
 import os
+import re
 import subprocess
 import sys
 
@@ -69,6 +70,15 @@ def main():
         '-s', sha
     ]
 
+    # Define a user tag.
+    try:
+        whoami = subprocess.check_output(['whoami'])
+        # Strip extra stuff (e.g. on Windows we are 'hostname\username')
+        whoami = re.sub(r'\w+[^\w]', '', whoami.strip())
+        swarming_args += ['-user', whoami]
+    except:
+        pass
+
     if args.gpu:
         swarming_args += ['-d', 'gpu=' + args.gpu]