Enable presubmit pylint in build/android.

build/android/pylib/system_properties.py

 # 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.
 
 
 class SystemProperties(dict):
 
   """A dict interface to interact with device system properties.
 
   System properties are key/value pairs as exposed by adb shell getprop/setprop.
@@ skipping 11 matching lines @@
     if self._IsStatic(key):
       if key not in self._cached_static_properties:
         self._cached_static_properties[key] = self._GetProperty(key)
       return self._cached_static_properties[key]
     return self._GetProperty(key)
 
   def __setitem__(self, key, value):
     # TODO(tonyg): This can fail with no root. Verify that it succeeds.
     self._adb.SendShellCommand('setprop %s "%s"' % (key, value), retry_count=3)
 
-  def _IsStatic(self, key):
+  @staticmethod
+  def _IsStatic(key):
     # TODO(tonyg): This list is conservative and could be expanded as needed.
     return (key.startswith('ro.boot.') or
             key.startswith('ro.build.') or
             key.startswith('ro.product.'))
 
   def _GetProperty(self, key):
     return self._adb.SendShellCommand('getprop %s' % key, retry_count=3).strip()