system_health.common_desktop failing on 7 builders

Builders failed on: 
- Linux Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Linux%20Perf
- Mac 10.12 Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Mac%2010.12%20Perf
- Mac Air 10.11 Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Mac%20Air%2010.11%20Perf
- Mac Pro 10.11 Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Mac%20Pro%2010.11%20Perf
- Mac Retina Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Mac%20Retina%20Perf
- Win 10 High-DPI Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Win%2010%20High-DPI%20Perf
- Win 7 Perf: 
  https://build.chromium.org/p/chromium.perf/builders/Win%207%20Perf


They seem to be timing out. What's the limit for a swarming task before it times out? These seem to have durations between 1-3 hrs.