Add perf timing to network_WiFi_SimpleConnect.

All three connection metrics are tracked and written to the
output file.  By default the perf tracking is ON for all tests
except:
  control.wifi_checkNonAsciiSSID
  control.wifi_checkOddWPAPassphrases
  control.wifi_checkRawPMK
  control.wifi_checkSGI
  control.wifi_checkSSIDLimits

BUG=chromium:338033
TEST=Ran it; manual.

Change-Id: I7b7242cce940a52a3410ff19300d688dded65d79
Reviewed-on: https://chromium-review.googlesource.com/207059
Tested-by: Kris Rambish <krisr@chromium.org>
Reviewed-by: Fang Deng <fdeng@chromium.org>
Reviewed-by: Kris Rambish <krisr@chromium.org>
Commit-Queue: Kris Rambish <krisr@chromium.org>
3 files changed