Constant organizing.

Move the constants from build_artifact and autoupdate into devserver_constants.
Neaten up XBuddy constants.

BUG=None
TEST=unittests + cbuildbot remote x86-mario

Change-Id: I6fba63f7533dc1349af8e8bdaad07564e4dc0a49
Reviewed-on: https://gerrit.chromium.org/gerrit/63773
Commit-Queue: Joy Chen <joychen@chromium.org>
Reviewed-by: Joy Chen <joychen@chromium.org>
Tested-by: Joy Chen <joychen@chromium.org>
diff --git a/devserver_constants.py b/devserver_constants.py
index 0fe0ee4..235f17d 100644
--- a/devserver_constants.py
+++ b/devserver_constants.py
@@ -18,8 +18,14 @@
 
 #### Local storage locations and names. ####
 AUTOTEST_DIR = 'autotest'
-UPDATE_FILE = 'update.gz'
-IMAGE_FILE = "chromiumos_image.bin"
 BASE_IMAGE_FILE = 'chromiumos_base_image.bin'
+IMAGE_FILE = 'chromiumos_image.bin'
+RECOVERY_IMAGE_FILE = 'recovery_image.bin'
+STATEFUL_UPDATE_FILE = 'stateful.tgz'
 TEST_IMAGE_FILE = 'chromiumos_test_image.bin'
-RECOVERY_IMAGE_FILE = 'recovery_image.bin'
\ No newline at end of file
+
+#### Update files
+CACHE_DIR = 'cache'
+METADATA_FILE = 'update.meta'
+STATEFUL_FILE = 'stateful.tgz'
+UPDATE_FILE = 'update.gz'