[Android] Reland of Remove android_commands and android_testrunner.

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.
-
-  This implementation minimizes interaction with the physical device. It is
-  valid for the lifetime of a boot.
-  """
-
-  def __init__(self, android_commands):
-    super(SystemProperties, self).__init__()
-    self._adb = android_commands
-    self._cached_static_properties = {}
-
-  def __getitem__(self, key):
-    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)
-
-  @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()