video_WebRtcPerf: add power and CPU usage test for WebRTC.

Run on the devices that support VP8 HW decode. Run using HW only:
- control: bvt test. Fails if hardware acceleration is not used.
- control.daily: Watch the regression of CPU usage and decode time.
- control.webrtc: Watch the regression of power consumption.

Run on all devices. Run twice using HW and SW:
- control.weekly: Measure the CPU usage and decode time weekly.

BUG=chromium:391396
TEST=Run the test on different CrOS devices.
CQ-DEPEND=CL:216446

Change-Id: I03fce20e2006256689da7a403f63a58ab8ded0d5
Reviewed-on: https://chromium-review.googlesource.com/214746
Tested-by: Wu-Cheng Li <wuchengli@chromium.org>
Reviewed-by: Wu-Cheng Li <wuchengli@chromium.org>
Commit-Queue: Wu-Cheng Li <wuchengli@chromium.org>
13 files changed