Hi,

the WebRTC Win7 perf bot started to fail on 21/06 without a clear reason.

Here is an example: https://ci.chromium.org/buildbot/client.webrtc.perf/Win7/6279.

The step webrtc_perf_tests fails after 43 minutes and 47 seconds, the log is not available but on swarming I can see the task succeeded: https://chromium-swarm.appspot.com/task?id=3e59ab088443bb10.

The execution timeout should be 60 minutes, so I exclude it is a timeout.

Similar tests (on other OS) are working:
- https://ci.chromium.org/buildbot/client.webrtc.perf/Linux%20Trusty/6522
- https://ci.chromium.org/buildbot/client.webrtc.perf/Mac%2010.11/6569

And before the 21/06 this one was also working correctly:
https://ci.chromium.org/buildbot/client.webrtc.perf/Win7/6236

Setting to P1 because we need to restore the bot in order to avoid regressions.