Make remote_test_server use EmbeddedTestServer in HTTP mode.

SpawnedTestServer is being slowly (very slowly) phased out, since it
has been responsible for a large number of issues leading to flake on
the tree, and doesn't work on mobile platforms.

Bug: 492672
Change-Id: I106c01f5fb47a11655274f59da0ca622d36a0508
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2510794
Reviewed-by: Steven Valdez <svaldez@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823221}
GitOrigin-RevId: 8028fd8b557c7857692a92216e052fa90516221e
1 file changed