Remove non-functional check owners script that pre-dated gerrit.

The gerrit team has now official ways of validating owner files
https://android-review.googlesource.com/plugins/code-owners/Documentation/validation.html

BUG=312931985

Change-Id: Iafce62560bdd080cafb419af68acf24d86cdfc78
diff --git a/tools/OWNERS b/tools/OWNERS
deleted file mode 100644
index 7d666f1..0000000
--- a/tools/OWNERS
+++ /dev/null
@@ -1 +0,0 @@
-per-file warn.py,checkowners.py = chh@google.com
diff --git a/tools/checkowners.py b/tools/checkowners.py
deleted file mode 100755
index f037321..0000000
--- a/tools/checkowners.py
+++ /dev/null
@@ -1,87 +0,0 @@
-#!/usr/bin/python
-
-"""Parse and check syntax errors of a given OWNERS file."""
-
-import argparse
-import re
-import sys
-import urllib.request, urllib.parse, urllib.error
-import urllib.request, urllib.error, urllib.parse
-
-parser = argparse.ArgumentParser(description='Check OWNERS file syntax')
-parser.add_argument('-v', '--verbose', dest='verbose',
-                    action='store_true', default=False,
-                    help='Verbose output to debug')
-parser.add_argument('-c', '--check_address', dest='check_address',
-                    action='store_true', default=False,
-                    help='Check email addresses')
-parser.add_argument(dest='owners', metavar='OWNERS', nargs='+',
-                    help='Path to OWNERS file')
-args = parser.parse_args()
-
-gerrit_server = 'https://android-review.googlesource.com'
-checked_addresses = {}
-
-
-def echo(msg):
-  if args.verbose:
-    print(msg)
-
-
-def find_address(address):
-  if address not in checked_addresses:
-    request = (gerrit_server + '/accounts/?n=1&q=email:'
-               + urllib.parse.quote(address))
-    echo('Checking email address: ' + address)
-    result = urllib.request.urlopen(request).read()
-    checked_addresses[address] = result.find('"_account_id":') >= 0
-    if checked_addresses[address]:
-      echo('Found email address: ' + address)
-  return checked_addresses[address]
-
-
-def check_address(fname, num, address):
-  if find_address(address):
-    return 0
-  print('%s:%d: ERROR: unknown email address: %s' % (fname, num, address))
-  return 1
-
-
-def main():
-  # One regular expression to check all valid lines.
-  noparent = 'set +noparent'
-  email = '([^@ ]+@[^ @]+|\\*)'
-  emails = '(%s( *, *%s)*)' % (email, email)
-  file_directive = 'file: *([^ :]+ *: *)?[^ ]+'
-  directive = '(%s|%s|%s)' % (emails, noparent, file_directive)
-  glob = '[a-zA-Z0-9_\\.\\-\\*\\?]+'
-  globs = '(%s( *, *%s)*)' % (glob, glob)
-  perfile = 'per-file +' + globs + ' *= *' + directive
-  include = 'include +([^ :]+ *: *)?[^ ]+'
-  pats = '(|%s|%s|%s|%s|%s)$' % (noparent, email, perfile, include, file_directive)
-  patterns = re.compile(pats)
-  address_pattern = re.compile('([^@ ]+@[^ @]+)')
-  perfile_pattern = re.compile('per-file +.*=(.*)')
-
-  error = 0
-  for fname in args.owners:
-    echo('Checking file: ' + fname)
-    num = 0
-    for line in open(fname, 'r'):
-      num += 1
-      stripped_line = re.sub('#.*$', '', line).strip()
-      if not patterns.match(stripped_line):
-        error += 1
-        print('%s:%d: ERROR: unknown line [%s]' % (fname, num, line.strip()))
-      elif args.check_address:
-        if perfile_pattern.match(stripped_line):
-          for addr in perfile_pattern.match(stripped_line).group(1).split(','):
-            a = addr.strip()
-            if a and a != '*':
-              error += check_address(fname, num, addr.strip())
-        elif address_pattern.match(stripped_line):
-          error += check_address(fname, num, stripped_line)
-  sys.exit(error)
-
-if __name__ == '__main__':
-  main()