Just checked the code.
Let DummyDolphinBFTFixture.IsDoubleCCCable() returns True solves this problem.

If you mentioned about [1] then I would say that is a hacky way to just skip the check by existed variable and will confuse the reader later about what actually DoubleCCCable mean.
  1. When IsDoubleCCable is true, it means the physical cable is really customized for not breaking a certain CC pin. But actually it will be not.
  2. Once a reader saw sample code about IsDoubleCCCable returned true, he/her might take a real DoubleCCCable to do test. This will have problem because without Plankton board to cut off one CC pin, both of them will be with voltage and it violates the USB spec.

Proposed solution:
  Actually there is no necessary to consider original_enabled_cc [2]. We just need to use pytest of raiden_cc_flip_check for making sure operator really flip the cable and that is all (no matter what the original pin should be)

  Example test flow:
    5V Charging test -> 20V charging test (until here we checked CC X pin) -> raiden_cc_flip_check (making sure we flip to CC Y pin) -> 5V Charging test -> 20 charging Test (now CC Y pin is tested as well.)

[1] https://chromium.googlesource.com/chromiumos/platform/factory/+/factory-oak-8182.B/py/test/pytests/raiden_cc_flip_check.py#181
[2] https://chromium.googlesource.com/chromiumos/platform/factory/+/factory-oak-8182.B/py/test/pytests/raiden_cc_flip_check.py#180

I tried to find out what is the usage of original_enabled_cc and the result is

  raiden_cc_flip_check is not only used to really ask for flipping but also used to just check whether current active CC pin is the original_enabled_cc or not. In this case, ask_flip_operation is false (with no double cc support of course.).

  Example test flow:
    raiden_cc_flip_check with "ask_flip_operation=false" (this makes sure we are on the CC1 now) -> test... -> raiden_cc_flip_check with "ask_flip_operation=true" (this makes sure we are on the CC2 now).

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/factory/+/5e7bbdfc461007d8b504c0f76de161b488351693

commit 5e7bbdfc461007d8b504c0f76de161b488351693
Author: Marco Chen <marcochen@chromium.org>
Date: Mon Jan 16 05:46:42 2017

raiden_cc_flip_check: Allow to start from any polarity.

Currently when ask_flip_operation is True, the test will check whether current
CC pin is CC1 or CC2 which is set as original_enabled_cc. What if we don't care
what CC pin now is and just would like to flip the calbe. The new value - None
of orignal_enabled_cc is added for this purpose.

BUG= chromium:680452 
TEST=manual

Change-Id: I637e1f943cddfe173dbb51f303cff30b82796ceb
Reviewed-on: https://chromium-review.googlesource.com/428533
Commit-Ready: Marco Chen <marcochen@chromium.org>
Tested-by: Marco Chen <marcochen@chromium.org>
Reviewed-by: Pin-chih Lin <johnylin@chromium.org>

[modify] https://crrev.com/5e7bbdfc461007d8b504c0f76de161b488351693/py/test/pytests/raiden_cc_flip_check.py

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/factory/+/8b7f9d9cffd7aa7222133f39416e935fe5350d35

commit 8b7f9d9cffd7aa7222133f39416e935fe5350d35
Author: Marco Chen <marcochen@chromium.org>
Date: Mon Jan 16 05:46:42 2017

raiden_cc_flip_check: Allow to start from any polarity.

Currently when ask_flip_operation is True, the test will check whether current
CC pin is CC1 or CC2 which is set as original_enabled_cc. What if we don't care
what CC pin now is and just would like to flip the calbe. The new value - None
of orignal_enabled_cc is added for this purpose.

BUG= chromium:680452 
TEST=manual

Change-Id: I637e1f943cddfe173dbb51f303cff30b82796ceb
Reviewed-on: https://chromium-review.googlesource.com/428533
Commit-Ready: Marco Chen <marcochen@chromium.org>
Tested-by: Marco Chen <marcochen@chromium.org>
Reviewed-by: Pin-chih Lin <johnylin@chromium.org>
(cherry picked from commit 5e7bbdfc461007d8b504c0f76de161b488351693)
Reviewed-on: https://chromium-review.googlesource.com/428481
Reviewed-by: Shun-Hsing Ou <shunhsingou@chromium.org>
Commit-Queue: Marco Chen <marcochen@chromium.org>

[modify] https://crrev.com/8b7f9d9cffd7aa7222133f39416e935fe5350d35/py/test/pytests/raiden_cc_flip_check.py