Update from https://crrev.com/320931

build/android/tombstones.py

 #!/usr/bin/env python
 #
 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 # Find the most recent tombstone file(s) on all connected devices
 # and prints their stacks.
 #
 # Assumes tombstone file was created with current symbols.
 
 import datetime
 import multiprocessing
 import os
 import re
 import subprocess
 import sys
 import optparse
 
 from pylib import android_commands
+from pylib.device import device_errors
 from pylib.device import device_utils
 
 
+_TZ_UTC = {'TZ': 'UTC'}
+
 def _ListTombstones(device):
   """List the tombstone files on the device.
 
   Args:
     device: An instance of DeviceUtils.
 
   Yields:
     Tuples of (tombstone filename, date time of file on device).
   """
-  lines = device.RunShellCommand('TZ=UTC su -c ls -a -l /data/tombstones')
+  lines = device.RunShellCommand(
+      ['ls', '-a', '-l', '/data/tombstones'],
+      as_root=True, check_return=True, env=_TZ_UTC, timeout=60)
   for line in lines:
     if 'tombstone' in line and not 'No such file or directory' in line:
       details = line.split()
       t = datetime.datetime.strptime(details[-3] + ' ' + details[-2],
                                      '%Y-%m-%d %H:%M')
       yield details[-1], t
 
 
 def _GetDeviceDateTime(device):
   """Determine the date time on the device.
 
   Args:
     device: An instance of DeviceUtils.
 
   Returns:
     A datetime instance.
   """
-  device_now_string = device.RunShellCommand('TZ=UTC date')
+  device_now_string = device.RunShellCommand(
+      ['date'], check_return=True, env=_TZ_UTC)
   return datetime.datetime.strptime(
       device_now_string[0], '%a %b %d %H:%M:%S %Z %Y')
 
 
 def _GetTombstoneData(device, tombstone_file):
   """Retrieve the tombstone data from the device
 
   Args:
     device: An instance of DeviceUtils.
     tombstone_file: the tombstone to retrieve
 
   Returns:
     A list of lines
   """
   return device.ReadFile(
       '/data/tombstones/' + tombstone_file, as_root=True).splitlines()
 
 
 def _EraseTombstone(device, tombstone_file):
   """Deletes a tombstone from the device.
 
   Args:
     device: An instance of DeviceUtils.
     tombstone_file: the tombstone to delete.
   """
   return device.RunShellCommand(
-      'rm /data/tombstones/' + tombstone_file, as_root=True)
+      ['rm', '/data/tombstones/' + tombstone_file],
+      as_root=True, check_return=True)
 
 
 def _DeviceAbiToArch(device_abi):
   # The order of this list is significant to find the more specific match (e.g.,
   # arm64) before the less specific (e.g., arm).
   arches = ['arm64', 'arm', 'x86_64', 'x86_64', 'x86', 'mips']
   for arch in arches:
     if arch in device_abi:
       return arch
   raise RuntimeError('Unknown device ABI: %s' % device_abi)
@@ skipping 76 matching lines @@
     print 'No device attached?  Or no tombstones?'
     return ret
 
   # Sort the tombstones in date order, descending
   all_tombstones.sort(cmp=lambda a, b: cmp(b[1], a[1]))
 
   # Only resolve the most recent unless --all-tombstones given.
   tombstones = all_tombstones if options.all_tombstones else [all_tombstones[0]]
 
   device_now = _GetDeviceDateTime(device)
-  for tombstone_file, tombstone_time in tombstones:
-    ret += [{'serial': str(device),
-             'device_abi': device.product_cpu_abi,
-             'device_now': device_now,
-             'time': tombstone_time,
-             'file': tombstone_file,
-             'stack': options.stack,
-             'data': _GetTombstoneData(device, tombstone_file)}]
+  try:
+    for tombstone_file, tombstone_time in tombstones:
+      ret += [{'serial': str(device),
+               'device_abi': device.product_cpu_abi,
+               'device_now': device_now,
+               'time': tombstone_time,
+               'file': tombstone_file,
+               'stack': options.stack,
+               'data': _GetTombstoneData(device, tombstone_file)}]
+  except device_errors.CommandFailedError:
+    for line in device.RunShellCommand(
+        ['ls', '-a', '-l', '/data/tombstones'],
+        as_root=True, check_return=True, env=_TZ_UTC, timeout=60):
+      print '%s: %s' % (str(device), line)
+    raise
 
   # Erase all the tombstones if desired.
   if options.wipe_tombstones:
     for tombstone_file, _ in all_tombstones:
       _EraseTombstone(device, tombstone_file)
 
   return ret
 
 
 def main():
@@ skipping 21 matching lines @@
 
   tombstones = []
   for device_serial in devices:
     device = device_utils.DeviceUtils(device_serial)
     tombstones += _GetTombstonesForDevice(device, options)
 
   _ResolveTombstones(options.jobs, tombstones)
 
 if __name__ == '__main__':
   sys.exit(main())