While looking at red win bots on the waterfall, I noticed multiple errors where the test is unable to delete the trace file because some other process was using it. Note that the info log that we successfully shut down the browser happens *after* telemetry fails to delete the log.

Should we be waiting until after Chrome is shut down to remove the trace files?

Example:
INFO:root:Chrome version: 2981
ERROR:root:Error when deleting c:\b\s\w\itdsvdhw\tmpvakwko, will try again at exit.
Traceback (most recent call last):
  File "c:\b\s\w\iryqshpv\third_party\catapult\telemetry\telemetry\internal\platform\tracing_controller_backend.py", line 272, in CollectAgentTraceData
    os.remove(self._trace_log)
WindowsError: [Error 32] The process cannot access the file because it is being used by another process: 'c:\\b\\s\\w\\itdsvdhw\\tmpvakwko'
INFO:root:Trace sizes in bytes: {TraceDataPart("traceEvents"): 18579672L, TraceDataPart("telemetry"): 48440L, TraceDataPart("tabIds"): 40L}
[ RUN      ] c:\b\s\w\itdsvdhw\tmp52t0zz.html
[       OK ] c:\b\s\w\itdsvdhw\tmp52t0zz.html (26909 ms)
[       OK ] load:tools:weather (105107 ms)
INFO:root:Successfully shut down browser cooperatively


From test stdio log: https://uberchromegw.corp.google.com/i/chromium.perf/builders/Win%20Zenbook%20Perf/builds/176/steps/system_health.common_desktop%20on%20Intel%20GPU%20on%20Windows%20on%20Windows-10-10240/logs/stdio