Add delta support to images generated by the dev server.

autoupdate.py

Index: autoupdate.py
diff --git a/autoupdate.py b/autoupdate.py
index b997ca39902e85a2e29aa2f34165a56d75e5f4f2..351b451b94555ba37d8f5a67c1c20a92bdd54dc9 100644
--- a/autoupdate.py
+++ b/autoupdate.py
@@ -31,7 +31,7 @@ class Autoupdate(BuildObject):
 
   def __init__(self, serve_only=None, test_image=False, urlbase=None,
                factory_config_path=None, client_prefix=None, forced_image=None,
-               use_cached=False, port=8080, *args, **kwargs):
+               use_cached=False, port=8080, src_image='', *args, **kwargs):
     super(Autoupdate, self).__init__(*args, **kwargs)
     self.serve_only = serve_only
     self.factory_config = factory_config_path
@@ -44,6 +44,7 @@ class Autoupdate(BuildObject):
     self.client_prefix = client_prefix
     self.forced_image = forced_image
     self.use_cached = use_cached
+    self.src_image = src_image
 
   def _GetSecondsSinceMidnight(self):
     """Returns the seconds since midnight as a decimal value."""
@@ -220,8 +221,11 @@ class Autoupdate(BuildObject):
     _LogMessage('Generating update image %s' % update_path)
 
     mkupdate_command = (
-        '%s/cros_generate_update_payload --image=%s --output=%s '
-        '--patch_kernel' % (self.scripts_dir, image_path, update_path))
+        '%s/cros_generate_update_payload --image="%s" --output="%s" '
+        '--patch_kernel --noold_style --src_image="%s"' % (
+                                          self.scripts_dir, image_path,
+                                          update_path, self.src_image))
+    _LogMessage(mkupdate_command)
     if os.system(mkupdate_command) != 0:
       _LogMessage('Failed to create base update file')
       return None