Simulate transient error and verify exponential backoff.

net/tools/testserver/chromiumsync_test.py

Index: net/tools/testserver/chromiumsync_test.py
diff --git a/net/tools/testserver/chromiumsync_test.py b/net/tools/testserver/chromiumsync_test.py
index af8aa360bd40f40a09cca9d17c98ee24e74d6c5a..662de37ee5b62c9cfc8b8b892580ef2c0b11a103 100755
--- a/net/tools/testserver/chromiumsync_test.py
+++ b/net/tools/testserver/chromiumsync_test.py
@@ -437,6 +437,16 @@ class SyncDataModelTest(unittest.TestCase):
     self.assertEqual(pickle.loads(marker.token), (3000, 1))
     self.assertFalse(marker.HasField('timestamp_token_for_migration'))
 
+  def testCheckRaiseTransientError(self):
+    testserver = chromiumsync.TestServer()
+    http_code, raw_respon = testserver.HandleSetTransientError()
+    self.assertEqual(http_code, 200)
+    try:
+      testserver.CheckTransientError()
+      self.fail('Should have raised transient error exception')
+    except chromiumsync.TransientError:
+      self.assertTrue(testserver.transient_error)
+
   def testUpdateSieveStoreMigration(self):
     autofill = autofill_specifics_pb2.autofill
     theme = theme_specifics_pb2.theme
@@ -550,6 +560,5 @@ class SyncDataModelTest(unittest.TestCase):
     sieve = chromiumsync.UpdateSieve(msg, migrator)
     sieve.CheckMigrationState()
 
-
 if __name__ == '__main__':
   unittest.main()