End to end WiFi integration test.

Tests that Chrome can do the following using chrome.networkingPrivate:
* Find available wifi networks.
* Transition to a different, currently unconnected network.
* Disable / Enable wifi.

BUG=chromium:382762
TEST=Tested against a DUT in a WiFi cell in the lab.
CQ-DEPEND=CL:205281

Change-Id: I2fdf124a192c5a9942ea5117c3df3d25e56d33db
Reviewed-on: https://chromium-review.googlesource.com/203089
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Kris Rambish <krisr@chromium.org>
Reviewed-by: harpreet Grewal <harpreet@chromium.org>
Tested-by: harpreet Grewal <harpreet@chromium.org>
Commit-Queue: harpreet Grewal <harpreet@chromium.org>
8 files changed