Example failure:

https://build.chromium.org/p/chromium.perf/builders/Mac%2010.11%20Perf%20%281%29/builds/3496/steps/power.gpu_rasterization.top_10/logs/stdio

Traceback (most recent call last):
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 87, in _RunStoryAndProcessErrorIfNeeded
    state.RunStory(results)
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 301, in RunStory
    self._current_page, self._current_tab, results)
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 52, in traced_function
    return func(*args, **kwargs)
  File "/b/c/b/Mac_10_11_Perf__1_/src/tools/perf/measurements/power.py", line 62, in ValidateAndMeasurePage
    util.WaitFor(tab.HasReachedQuiescence, 60)
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/telemetry/telemetry/decorators.py", line 75, in wrapper
    return target(*args, **kwargs)
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/telemetry/telemetry/core/util.py", line 65, in WaitFor
    return catapult_util.WaitFor(condition, timeout)
  File "/b/c/b/Mac_10_11_Perf__1_/src/third_party/catapult/common/py_utils/py_utils/__init__.py", line 132, in WaitFor
    (timeout, GetConditionString()))
TimeoutException: Timed out while waiting 60s for HasReachedQuiescence.

This is failing very frequently on Mac so I'm gonna disable this page.