The following tests have failed on various recent runs of VMTest on amd64-generic-chromium-pfq:
login_Cryptohome
login_LoginSuccess
login_CryptohomeIncognito
login_OwnershipNotRetaken
login_LogoutProcessCleanup
  and
security_NetworkListeners

First failure occurred on 
  https://uberchromegw.corp.google.com/i/chromeos/builders/amd64-generic-chromium-pfq/builds/11740
subsequent 3 runs see similar failures.

All error logs look like

03/14 00:13:28.941 ERROR|               log:0027| pre-test siteration sysinfo error:
03/14 00:13:28.944 ERROR|         traceback:0013| Traceback (most recent call last):
03/14 00:13:28.947 ERROR|         traceback:0013|   File "/usr/local/autotest/common_lib/log.py", line 25, in decorated_func
03/14 00:13:28.950 ERROR|         traceback:0013|     fn(*args, **dargs)
03/14 00:13:28.953 ERROR|         traceback:0013|   File "/usr/local/autotest/bin/base_sysinfo.py", line 394, in log_before_each_iteration
03/14 00:13:28.956 ERROR|         traceback:0013|     board = utils.get_board_with_frequency_and_memory()
03/14 00:13:28.959 ERROR|         traceback:0013|   File "/usr/local/autotest/bin/utils.py", line 2025, in get_board_with_frequency_and_memory
03/14 00:13:28.964 ERROR|         traceback:0013|     frequency = int(round(get_cpu_max_frequency() * 1e-8)) * 0.1
03/14 00:13:28.967 ERROR|         traceback:0013|   File "/usr/local/autotest/bin/utils.py", line 1852, in get_cpu_max_frequency
03/14 00:13:28.970 ERROR|         traceback:0013|     paths = _get_cpufreq_paths('cpuinfo_max_freq')
03/14 00:13:28.973 ERROR|         traceback:0013|   File "/usr/local/autotest/bin/utils.py", line 2109, in _get_cpufreq_paths
03/14 00:13:28.976 ERROR|         traceback:0013|     paths = utils.run(cmd, verbose=False).stdout.splitlines()
03/14 00:13:28.979 ERROR|         traceback:0013|   File "/usr/local/autotest/common_lib/utils.py", line 748, in run
03/14 00:13:28.982 ERROR|         traceback:0013|     "Command returned non-zero exit status")
03/14 00:13:28.986 ERROR|         traceback:0013| CmdError: Command <ls /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_max_freq> failed, rc=2, Command returned non-zero exit status
03/14 00:13:28.989 ERROR|         traceback:0013| * Command: 
03/14 00:13:28.992 ERROR|         traceback:0013|     ls /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_max_freq
03/14 00:13:28.995 ERROR|         traceback:0013| Exit status: 2
03/14 00:13:28.998 ERROR|         traceback:0013| Duration: 0.00167512893677
03/14 00:13:29.000 ERROR|         traceback:0013| 
03/14 00:13:29.003 ERROR|         traceback:0013| stderr:
03/14 00:13:29.006 ERROR|         traceback:0013| ls: cannot access '/sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_max_freq': No such file or directory
03/14 00:13:31.804 ERROR|           browser:0057| Failed with DevtoolsTargetCrashException while starting the browser backend.
  (or sometimes)
03/14 05:53:06.240 ERROR|           browser:0057| Failed with BrowserConnectionGoneException while starting the browser backend.