Change update logic to be backwards compatible with old format.

autoupdate.py

 # Copyright (c) 2009-2010 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.
 
 from buildutil import BuildObject
 from xml.dom import minidom
 import cherrypy
 import os
 import shutil
 import subprocess
@@ skipping 243 matching lines @@
                              '--read_only',
                              '--rootfs_mountpt=%s' % rootfs_dir,
                              '--stateful_mountpt=%s' % stateful_dir,
                             ])
       _LogMessage('Tarring up /usr/local and /var!')
       subprocess.check_call(['sudo',
                              'tar',
                              '-czf',
                              output_gz,
                              '--directory=%s' % stateful_dir,
+                             '--transform=s,^dev_image,dev_image_new,',
+                             '--transform=s,^var,var_new,',
                              'dev_image',
                              'var',
                             ])
     except:
       _LogMessage('Failed to create stateful update file')
       raise
     finally:
       # Unmount best effort regardless.
       subprocess.call(['%s/mount_gpt_image.sh' % self.crosutils,
                        '--unmount',
@@ skipping 314 matching lines @@
         is_delta_format = self._IsDeltaFormatFile(filename)
         if label:
           url = '%s/%s/update.gz' % (static_urlbase, label)
         else:
           url = '%s/update.gz' % static_urlbase
 
         _LogMessage('Responding to client to use url %s to get image.' % url)
         return self.GetUpdatePayload(hash, sha256, size, url, is_delta_format)
       else:
         return self.GetNoUpdatePayload()