Never try to populate the LASTCHANGE file in non-standalone checkout

Since the build/ directory is checked out behind 'dawn_standalone', the
'lastchange' hook depending on that should be guarded by the same

Bug: dawn:437
Change-Id: If6d1f5ee505eab5bc5519ec6d29b2efe5d69d9aa
Reviewed-by: Corentin Wallez <>
Reviewed-by: Austin Eng <>
Commit-Queue: Jiajie Hu <>
diff --git a/DEPS b/DEPS
index 13c8d79..1be6083 100644
--- a/DEPS
+++ b/DEPS
@@ -222,6 +222,7 @@
     'name': 'lastchange',
     'pattern': '.',
+    'condition': 'dawn_standalone',
     'action': ['python', 'build/util/',
                '-o', 'build/util/LASTCHANGE'],