kerrnel@ may I know how do you run/test platform_ImageLoader?

It's launched by platform_ImageLoaderServer.

test_that -b ${BOARD} ${IP} platform_ImageLoaderServer

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/autotest/+/186c0ff72193c9daf7ea2a7e096a7d4c9fb14521

commit 186c0ff72193c9daf7ea2a7e096a7d4c9fb14521
Author: Xiaochu Liu <xiaochu@chromium.org>
Date: Tue Nov 07 23:25:18 2017

platform_ImageLoader/platform_ImageLoaderServer: test RemoveComponent API

It downloads a prod signed removable component and register it with imageloader.
Then call RemoveComponent in imageloader to remove component.

BUG= chromium:774725 
TEST=test_that -b ${BOARD} ${IP} platform_ImageLoaderServer

Change-Id: Idfaa1e659ec75aee39c4ddb531ba0f98e7edc780
Reviewed-on: https://chromium-review.googlesource.com/731726
Commit-Ready: Xiaochu Liu <xiaochu@chromium.org>
Tested-by: Greg Kerr <kerrnel@chromium.org>
Reviewed-by: Greg Kerr <kerrnel@chromium.org>

[modify] https://crrev.com/186c0ff72193c9daf7ea2a7e096a7d4c9fb14521/server/site_tests/platform_ImageLoaderServer/platform_ImageLoaderServer.py
[modify] https://crrev.com/186c0ff72193c9daf7ea2a7e096a7d4c9fb14521/client/site_tests/platform_ImageLoader/platform_ImageLoader.py