cidb: (temporary fix) do not use cidb on unknown waterfalls

I forgot about the chromeos.chrome waterfall when landing the cidb
change. This CL disables cidb for that waterfall, and any other
waterfall that is not known to the existing db schema.

BUG=None
TEST=Unit tests pass

Change-Id: I398946a90850049b4418138933ab36ba4c13a28c
Reviewed-on: https://chromium-review.googlesource.com/213903
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Daniel Jacques <dnj@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
diff --git a/scripts/cbuildbot.py b/scripts/cbuildbot.py
index 7dc3fd0..8082753 100644
--- a/scripts/cbuildbot.py
+++ b/scripts/cbuildbot.py
@@ -1675,6 +1675,14 @@
     cidb.CIDBConnectionFactory.SetupNoCidb()
     return
 
+  # TODO(akeshet): This is a temporary workaround to make sure that the cidb
+  # is not used on waterfalls that the db schema does not support (in particular
+  # the chromeos.chrome waterfall).
+  waterfall = os.environ.get('BUILDBOT_MASTERNAME', '')
+  if not waterfall in ('chromeos', 'chromiumos', 'chromiumos.tryserver'):
+    cidb.CIDBConnectionFactory.SetupNoCidb()
+    return
+
   if options.debug:
     cidb.CIDBConnectionFactory.SetupDebugCidb()
   else: