Add an assert to ensure UTF-8 locale when handling file paths.

appengine/swarming/remote_smoke_test.py

Index: appengine/swarming/remote_smoke_test.py
diff --git a/appengine/swarming/remote_smoke_test.py b/appengine/swarming/remote_smoke_test.py
index 70ea38c21ac89b1804d59351bd0c9842ff5f42a9..119454ca0012be8b2e21217bb63fa8e26a22d415 100755
--- a/appengine/swarming/remote_smoke_test.py
+++ b/appengine/swarming/remote_smoke_test.py
@@ -10,7 +10,6 @@ import json
 import logging
 import optparse
 import os
-import shutil
 import subprocess
 import sys
 import tempfile
@@ -22,6 +21,11 @@ CHECKOUT_DIR = os.path.dirname(os.path.dirname(APP_DIR))
 CLIENT_DIR = os.path.join(CHECKOUT_DIR, 'client')
 SWARMING_SCRIPT = os.path.join(CLIENT_DIR, 'swarming.py')
 
+sys.path.insert(0, CLIENT_DIR)
+from third_party.depot_tools import fix_encoding
+from utils import file_path
+sys.path.pop(0)
+
 
 def gen_isolated(isolate, script, includes=None):
   """Archives a script to `isolate` server."""
@@ -61,7 +65,7 @@ def gen_isolated(isolate, script, includes=None):
       out = subprocess.check_output(cmd)
     return out.split(' ', 1)[0]
   finally:
-    shutil.rmtree(tmp)
+    file_path.rmtree(tmp)
 
 
 def capture(cmd, **kwargs):
@@ -193,6 +197,7 @@ def run_test(results, swarming, isolate, extra_flags, name, test_case):
 
 
 def main():
+  fix_encoding.fix_encoding()
   # It's necessary for relative paths in .isolate.
   os.chdir(APP_DIR)