Update from https://crrev.com/320343

base/android/jni_generator/jni_generator_tests.py

Index: base/android/jni_generator/jni_generator_tests.py
diff --git a/base/android/jni_generator/jni_generator_tests.py b/base/android/jni_generator/jni_generator_tests.py
index e29bc0cc46d48b8dc82d16f17451514d52db2355..60148470b31f0ec28d7e7bf7368b9b8b7e79e9b2 100755
--- a/base/android/jni_generator/jni_generator_tests.py
+++ b/base/android/jni_generator/jni_generator_tests.py
@@ -13,6 +13,7 @@ file.
 
 import difflib
 import inspect
+import optparse
 import os
 import sys
 import unittest
@@ -1148,5 +1149,27 @@ class Foo {
     self.assertGoldenTextEquals(jni_from_java.GetContent())
 
 
+def TouchStamp(stamp_path):
+  dir_name = os.path.dirname(stamp_path)
+  if not os.path.isdir(dir_name):
+    os.makedirs()
+
+  with open(stamp_path, 'a'):
+    os.utime(stamp_path, None)
+
+
+def main(argv):
+  parser = optparse.OptionParser()
+  parser.add_option('--stamp', help='Path to touch on success.')
+  options, _ = parser.parse_args(argv[1:])
+
+  test_result = unittest.main(argv=argv[0:1], exit=False)
+
+  if test_result.result.wasSuccessful() and options.stamp:
+    TouchStamp(options.stamp)
+
+  return not test_result.result.wasSuccessful()
+
+
 if __name__ == '__main__':
-  unittest.main()
+  sys.exit(main(sys.argv))