Use option_name / config_name to control skipping of 'chrome_sdk' stage.

This makes our logic for skipping stages more consistent.

BUG=none
TEST=Verify this stage is still skipped.

Change-Id: Ib2cb41d319cfdcc64c25c92bcb24e1799449062f
Reviewed-on: https://chromium-review.googlesource.com/239267
Trybot-Ready: David James <davidjames@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: David James <davidjames@chromium.org>
Tested-by: David James <davidjames@chromium.org>
diff --git a/scripts/cbuildbot.py b/scripts/cbuildbot.py
index 11a0b98..ebcb037 100644
--- a/scripts/cbuildbot.py
+++ b/scripts/cbuildbot.py
@@ -538,9 +538,7 @@
     # that make sense when read in order.  Also keep in mind that, since we
     # gather output manually, early slow stages will prevent any output from
     # later stages showing up until it finishes.
-    stage_list = []
-    if builder_run.options.chrome_sdk and config.chrome_sdk:
-      stage_list.append([chrome_stages.ChromeSDKStage, board])
+    stage_list = [[chrome_stages.ChromeSDKStage, board]]
 
     if config.vm_test_runs > 1:
       # Run the VMTests multiple times to see if they fail.