Logs: https://logs.chromium.org/v/?s=chromium%2Fbb%2Fchromium.clang%2FToTWinThinLTO64%2F404%2F%2B%2Frecipes%2Fsteps%2Fsizes%2F0%2Fstdout

Excerpt:
Sending result 1 of 141 to dashboard.
Confused: 2 files were deleted from c:\users\chrome~1\appdata\local\temp during the test run
Traceback (most recent call last):
  File "C:\b\rr\tmpzaf66u\rw\checkout\scripts\slave\results_dashboard.py", line 470, in _SendResultsJson
    urllib2.urlopen(req)
  File "C:\b\depot_tools\win_tools-2_7_6_bin\python\bin\lib\urllib2.py", line 127, in urlopen
    return _opener.open(url, data, timeout)
  File "C:\b\depot_tools\win_tools-2_7_6_bin\python\bin\lib\urllib2.py", line 410, in open
    response = meth(req, response)
  File "C:\b\depot_tools\win_tools-2_7_6_bin\python\bin\lib\urllib2.py", line 523, in http_response
    'http', request, response, code, msg, hdrs)
  File "C:\b\depot_tools\win_tools-2_7_6_bin\python\bin\lib\urllib2.py", line 448, in error
    return self._call_chain(*args)
  File "C:\b\depot_tools\win_tools-2_7_6_bin\python\bin\lib\urllib2.py", line 382, in _call_chain
    result = func(*args)
  File "C:\b\depot_tools\win_tools-2_7_6_bin\python\bin\lib\urllib2.py", line 531, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 403: Forbidden
Error uploading to dashboard.
step returned non-zero exit code: 87