This only happens on N5, all other devices are fine.

Revision range first seen: https://codereview.chromium.org/2550783002 (catapult roll with ref build update)
Link to failing step log:
https://uberchromegw.corp.google.com/i/chromium.perf/builders/Android%20Nexus5%20Perf%20%283%29/builds/4000
https://uberchromegw.corp.google.com/i/chromium.perf/builders/Android%20Nexus5%20Perf%20%283%29/builds/4000/steps/memory.long_running_idle_gmail_tbmv2.reference/logs/stdio

Traceback (most recent call last):
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/story_runner.py", line 89, in _RunStoryAndProcessErrorIfNeeded
    test.Measure(state.platform, results)
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/web_perf/timeline_based_measurement.py", line 290, in Measure
    trace_result = platform.tracing_controller.StopTracing()
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/core/tracing_controller.py", line 47, in StopTracing
    return self._tracing_controller_backend.StopTracing()
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/platform/tracing_controller_backend.py", line 130, in StopTracing
    '\n'.join(raised_exception_messages))
Error: Exceptions raised when trying to stop tracing:
Traceback (most recent call last):
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/platform/tracing_controller_backend.py", line 118, in StopTracing
    agent.CollectAgentTraceData(builder)
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/platform/tracing_agent/chrome_tracing_agent.py", line 246, in CollectAgentTraceData
    '\n'.join(raised_exception_messages))
ChromeTracingStoppedError: Exceptions raised when trying to collect Chrome devtool tracing:
Error when collecting Chrome tracing on devtools at port localabstract:chrome_devtools_remote:
Traceback (most recent call last):
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/platform/tracing_agent/chrome_tracing_agent.py", line 235, in CollectAgentTraceData
    client.CollectChromeTracingData(trace_data_builder)
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/devtools_client_backend.py", line 369, in CollectChromeTracingData
    self._tracing_backend.CollectTraceData(trace_data_builder, timeout)
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend.py", line 227, in CollectTraceData
    self._CollectTracingData(trace_data_builder, timeout)
  File "/b/rr/tmpnGLxEG/w/src/third_party/catapult/telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend.py", line 265, in _CollectTracingData
    'the timeout amount.' % elapsed_time)
TracingTimeoutException: Only received partial trace data due to timeout after 30.0287230015 seconds. If the trace data is big, you may want to increase the timeout amount.

If the test is disabled, please downgrade to Pri-2.