Re-re-land gclient deletion of mismatching checkouts again

gclient_utils.py

Index: gclient_utils.py
diff --git a/gclient_utils.py b/gclient_utils.py
index cad181e786b832f1ae56b7b5755a8547e1da50c2..ec69757b7fcdf9ae837638999a7f37538a6563cd 100644
--- a/gclient_utils.py
+++ b/gclient_utils.py
@@ -10,6 +10,7 @@ import os
 import pipes
 import Queue
 import re
+import socket
 import stat
 import subprocess
 import sys
@@ -25,6 +26,20 @@ RETRY_MAX = 3
 RETRY_INITIAL_SLEEP = 0.5
 
 
+def enable_deletion_of_conflicting_checkouts():
+  """Determines whether to enable new checkout deletion behavior.
+
+  Initially, enables the experimental functionality on a small set of
+  bots.
+  """
+  # TODO(borenet): Remove this hack as soon as we've verified that it
+  # doesn't cause the bots to break.
+  if not os.environ.get('CHROME_HEADLESS'):
+    return False
+  return socket.gethostname() in ('vm859-m1', 'BUILD1-M1',
+                                  'vm630-m1.golo.chromium.org')
+
+
 class Error(Exception):
   """gclient exception class."""
   def __init__(self, msg, *args, **kwargs):