autotest: Migrate 090_BgScanBackoff to new WiFi test framework
While here, observe that assert_ping_similarity() is only used for this
test and that belongs in the test rather that in WiFiClient. Use
blocking ping calls rather than background ping calls since this makes
the test lab team happier.
TEST=Test runs, stats are compared.
BUG=chromium:230660
CQ-DEPEND=CL:50905
Change-Id: I96944d9988bd1af85c6ad5dcce53c50569cb5b94
Reviewed-on: https://gerrit.chromium.org/gerrit/50907
Tested-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: Christopher Wiley <wiley@chromium.org>
7 files changed