autotest: power_LoadTest: Fixup extension code

This removes the depricated API calls onRequest and sendRequest which don't
work on Chrome on some platforms. It also calls setupTest though setTimeout
for the onClick option since that's what we do when running the code through
telemetry.

BUG=None
TEST=run power_LoadTest

Change-Id: I0a3a65b67401c3cfb7362bd28d3b2ce30fdaffcf
Reviewed-on: https://chromium-review.googlesource.com/274908
Tested-by: Derek Basehore <dbasehore@chromium.org>
Reviewed-by: Sameer Nanda <snanda@chromium.org>
Commit-Queue: Derek Basehore <dbasehore@chromium.org>
3 files changed