Start monitoring temperature during tests.

There are two parts to this:
1) Added infrastructure to site_utils.py to get machine into defined state
   and keep tests honest.
2) Change glbench binary to base its wait times on currently observed
   temperatures.

This should make the test faster, as we can cut down on blind sleep times.
But I don't expect on its own to change the numbers.

BUG=chromium:344766
TEST=1) Ran graphics_GLBench on link.
     2) Ran hardware_SsdDetection and firmware_TouchMTB on link to ensure
        get_board() still works for them.

Change-Id: I3cb908a35d911a3f9ca6ef194aa5a3d1ac3e2152
Reviewed-on: https://chromium-review.googlesource.com/190290
Reviewed-by: Ilja Friedel <ihf@chromium.org>
Commit-Queue: Ilja Friedel <ihf@chromium.org>
Tested-by: Ilja Friedel <ihf@chromium.org>
8 files changed