Change autox scons to get more environment variables

src/platform/autox/SConstruct

 # Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 
 env = Environment()
 for key in Split('CC CXX AR RANLIB LD NM'):
   value = os.environ.get(key)
   if value != None:
     env[key] = value
 for key in Split('CFLAGS CCFLAGS CPPPATH LIBPATH'):
   value = os.environ.get(key)
   if value != None:
     env[key] = Split(value)
 if not env.get('CCFLAGS'):
   env.Append(CCFLAGS=Split('-I.. -Wall -Werror -O3'))
 
-# Fix issue with scons not passing pkg-config vars through the environment.
-for key in Split('PKG_CONFIG_LIBDIR PKG_CONFIG_PATH'):
+# Fix issue with scons not passing some vars through the environment.
+for key in Split('PKG_CONFIG_LIBDIR PKG_CONFIG_PATH SYSROOT'):
   if os.environ.has_key(key):
     env['ENV'][key] = os.environ[key]
 
 env.Append(CPPPATH=['..'])
 env.Append(LIBS=Split('base chromeos rt Xtst'))
 env.ParseConfig('pkg-config --cflags --libs libpcrecpp x11')
 env.Program('autox', Split('autox.cc script_runner.cc'))