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/build_artifact.py b/build_artifact.py
index 7bfd27f..2970ea1 100755
--- a/build_artifact.py
+++ b/build_artifact.py
@@ -30,7 +30,6 @@
 DEBUG_SYMBOLS_FILE = 'debug.tgz'
 FIRMWARE_FILE = 'firmware_from_source.tar.bz2'
 IMAGE_FILE = 'image.zip'
-STATEFUL_UPDATE_FILE = 'stateful.tgz'
 TEST_SUITES_FILE = 'test_suites.tar.bz2'
 
 _build_artifact_locks = common_util.LockDict()
@@ -227,8 +226,10 @@
         artifact.Process(no_wait=True)
         # Setup symlink so that AU will work for this payload.
         os.symlink(
-            os.path.join(os.pardir, os.pardir, STATEFUL_UPDATE_FILE),
-            os.path.join(artifact.install_dir, STATEFUL_UPDATE_FILE))
+            os.path.join(os.pardir, os.pardir,
+                         devserver_constants.STATEFUL_UPDATE_FILE),
+            os.path.join(artifact.install_dir,
+                         devserver_constants.STATEFUL_UPDATE_FILE))
       except ArtifactDownloadError as e:
         self._Log('Could not process %s: %s', artifact, e)
 
@@ -360,7 +361,7 @@
   artifact_info.DELTA_PAYLOADS:
       ImplDescription(DeltaPayloadsArtifact, '.*_delta_.*'),
   artifact_info.STATEFUL_PAYLOAD:
-      ImplDescription(BuildArtifact, STATEFUL_UPDATE_FILE),
+      ImplDescription(BuildArtifact, devserver_constants.STATEFUL_UPDATE_FILE),
 
   artifact_info.BASE_IMAGE:
       ImplDescription(ZipfileBuildArtifact, IMAGE_FILE,