Update from https://crrev.com/327068

testing/scripts/gtest_perf_test.py

Index: testing/scripts/gtest_perf_test.py
diff --git a/testing/scripts/gtest_perf_test.py b/testing/scripts/gtest_perf_test.py
index 6243a79dc2c53e41c1bda92df0a6032316a4f4a6..af4380f65710658bc5c8a02a3ddc46b7f85cb063 100755
--- a/testing/scripts/gtest_perf_test.py
+++ b/testing/scripts/gtest_perf_test.py
@@ -11,6 +11,10 @@ import sys
 import common
 
 
+def IsWindows():
+  return sys.platform == 'cygwin' or sys.platform.startswith('win')
+
+
 def main_run(args):
   filter_tests = []
   if args.filter_file:
@@ -19,6 +23,8 @@ def main_run(args):
   perf_id = args.properties.get('perf-id')
   script_args = args.args
   test_suite = script_args[0]
+  if IsWindows():
+    script_args[0] += '.exe'
 
   with common.temporary_file() as tempfile_path:
     gtest_args = [