Sample link: https://ci.chromium.org/buildbot/chromium.perf/Android%20Nexus6%20WebView%20Perf/2657

Error in the logs:

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/b/swarming/w/ir/.swarming_module/lib/python2.7/threading.py", line 801, in __bootstrap_inner
    self.run()
  File "/b/swarming/w/ir/.swarming_module/lib/python2.7/threading.py", line 754, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/b/swarming/w/ir/third_party/catapult/devil/devil/android/perf/surface_stats_collector.py", line 74, in _CollectorThread
    raise Exception('Unable to get surface flinger latency data')
Exception: Unable to get surface flinger latency data
...
...
...
Traceback (most recent call last):
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 126, in _RunStoryAndProcessErrorIfNeeded
    state.RunStory(results)
  File "/b/swarming/w/ir/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/swarming/w/ir/third_party/catapult/telemetry/telemetry/page/shared_page_state.py", line 302, in RunStory
    self._current_page, self._current_tab, results)
  File "/b/swarming/w/ir/third_party/catapult/common/py_trace_event/py_trace_event/trace_event_impl/decorators.py", line 75, in traced_function
    return func(*args, **kwargs)
  File "/b/swarming/w/ir/tools/perf/measurements/rendering.py", line 62, in ValidateAndMeasurePage
    trace_result = tab.browser.platform.tracing_controller.StopTracing()
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/core/tracing_controller.py", line 53, in StopTracing
    return self._tracing_controller_backend.StopTracing()
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/platform/tracing_controller_backend.py", line 157, in StopTracing
    '\n'.join(raised_exception_messages))
TracingException: Exceptions raised when trying to stop tracing:
Traceback (most recent call last):
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/platform/tracing_controller_backend.py", line 145, in StopTracing
    agent.CollectAgentTraceData(builder)
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/platform/tracing_agent/display_tracing_agent.py", line 30, in CollectAgentTraceData
    surface_flinger_trace_data = self._platform_backend.StopDisplayTracing()
  File "/b/swarming/w/ir/third_party/catapult/telemetry/telemetry/internal/platform/android_platform_backend.py", line 190, in StopDisplayTracing
    refresh_period, timestamps = self._surface_stats_collector.Stop()
  File "/b/swarming/w/ir/third_party/catapult/devil/devil/android/perf/surface_stats_collector.py", line 47, in Stop
    (refresh_period, timestamps) = self._GetDataFromThread()
  File "/b/swarming/w/ir/third_party/catapult/devil/devil/android/perf/surface_stats_collector.py", line 95, in _GetDataFromThread
    raise ret
Exception: Unable to get surface flinger latency data

Looks like there may still be some issues in surface_stats_collector.py. This seems related to  issue 881873 .