cros_flash: Remove experimental-au flag

We never get to use this, so remove it.

BUG=None
TEST=run_pytest

Change-Id: Ib76164802e04af665667414f075ca1d4a67a316d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2242101
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Amin Hassani <ahassani@chromium.org>
diff --git a/cli/cros/cros_flash.py b/cli/cros/cros_flash.py
index 077279f..bbf466f 100644
--- a/cli/cros/cros_flash.py
+++ b/cli/cros/cros_flash.py
@@ -100,10 +100,6 @@
         help='Clear the devserver static directory. This deletes all the '
         'downloaded images and payloads, and also payloads generated by '
         'the devserver. Default is not to clear.')
-    parser.add_argument(
-        '--experimental-au', default=False, action='store_true',
-        help='Use the experimental features of auto updater. It should be '
-        'removed once crbug.com/872441 is fixed.')
 
     update = parser.add_argument_group('Advanced device update options')
     update.add_argument(
@@ -201,8 +197,7 @@
           yes=self.options.yes,
           force=self.options.force,
           debug=self.options.debug,
-          send_payload_in_parallel=self.options.send_payload_in_parallel,
-          experimental_au=self.options.experimental_au)
+          send_payload_in_parallel=self.options.send_payload_in_parallel)
       logging.notice('cros flash completed successfully.')
     except dev_server_wrapper.ImagePathError:
       logging.error('To get the latest remote image, please run:\n'
diff --git a/cli/cros/cros_flash_unittest.py b/cli/cros/cros_flash_unittest.py
index 1473626..8332c0f 100644
--- a/cli/cros/cros_flash_unittest.py
+++ b/cli/cros/cros_flash_unittest.py
@@ -94,7 +94,6 @@
         'force': False,
         'debug': False,
         'send_payload_in_parallel': False,
-        'experimental_au': False,
     }
     # Overwrite defaults with any variations in this test.
     expected_kwargs.update(kwargs)
diff --git a/cli/flash.py b/cli/flash.py
index 13fe016..a1c763f 100644
--- a/cli/flash.py
+++ b/cli/flash.py
@@ -364,7 +364,7 @@
                board=None, src_image_to_delta=None, wipe=True, debug=False,
                yes=False, force=False, ssh_private_key=None, ping=True,
                disable_verification=False, send_payload_in_parallel=False,
-               experimental_au=False, version=None):
+               version=None):
     """Initializes RemoteDeviceUpdater"""
     if not stateful_update and not rootfs_update:
       raise ValueError('No update operation to perform; either stateful or'
@@ -388,7 +388,6 @@
     self.yes = yes
     self.force = force
     self.send_payload_in_parallel = send_payload_in_parallel
-    self.experimental_au = experimental_au
     self.version = version
 
   def Cleanup(self):
@@ -525,7 +524,6 @@
               clobber_stateful=self.clobber_stateful,
               yes=self.yes,
               send_payload_in_parallel=self.send_payload_in_parallel,
-              experimental_au=self.experimental_au,
               transfer_class=auto_updater_transfer.LocalTransfer)
           chromeos_AU.CheckPayloads()
           chromeos_AU.RunUpdate()
@@ -553,7 +551,7 @@
           reboot=True, wipe=True, ssh_private_key=None, ping=True,
           disable_rootfs_verification=False, clear_cache=False, yes=False,
           force=False, debug=False, send_payload_in_parallel=False,
-          experimental_au=False, version=None):
+          version=None):
   """Flashes a device, USB drive, or file with an image.
 
   This provides functionality common to `cros flash` and `brillo flash`
@@ -583,8 +581,6 @@
     debug: Print additional debugging messages.
     send_payload_in_parallel: Transfer payloads in chunks in parallel to speed
         up transmissions for long haul between endpoints.
-    experimental_au: Use the experimental features auto updater. It should be
-        deprecated once crbug.com/872441 is fixed.
     version: Default version.
 
   Raises:
@@ -631,7 +627,6 @@
         ping=ping,
         disable_verification=disable_rootfs_verification,
         send_payload_in_parallel=send_payload_in_parallel,
-        experimental_au=experimental_au,
         version=version)
     updater.Run()
   elif device.scheme == commandline.DEVICE_SCHEME_USB:
diff --git a/lib/auto_updater.py b/lib/auto_updater.py
index 40dd977..7aafcae 100644
--- a/lib/auto_updater.py
+++ b/lib/auto_updater.py
@@ -152,7 +152,7 @@
                local_devserver=False, yes=False, do_rootfs_update=True,
                do_stateful_update=True, reboot=True, disable_verification=False,
                send_payload_in_parallel=False, payload_filename=None,
-               experimental_au=False, staging_server=None):
+               staging_server=None):
     """Initialize a ChromiumOSUpdater for auto-update a chromium OS device.
 
     Args:
@@ -185,8 +185,6 @@
           only if you staged a payload by filename (i.e not artifact) first.
       send_payload_in_parallel: whether to transfer payload in chunks
           in parallel. The default is False.
-      experimental_au: Use experimental features of auto updater instead. It
-          should be deprecated once crbug.com/872441 is fixed.
       staging_server: URL (str) of the server that's staging the payload files.
           Assuming transfer_class is None, if value for staging_server is None
           or empty, an auto_updater_transfer.LocalTransfer reference must be
@@ -219,7 +217,6 @@
     else:
       self.payload_mode = self.PAYLOAD_MODE_SCP
     self.perf_id = None
-    self.experimental_au = experimental_au
 
     if log_file:
       log_kwargs = {