Add unit tests for revving of Chrome prebuilts.

BUG=chromium:238338
TEST=Verify this unit test is broken by CL:49528
TEST=Verify this unit test is fixed by CL:50182
TEST=All unit tests
Change-Id: I50dfd7398cd13be9302ffba62c92640bfd04940a
Reviewed-on: https://gerrit.chromium.org/gerrit/50183
Tested-by: David James <davidjames@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Reviewed-by: Ryan Cui <rcui@chromium.org>
Commit-Queue: David James <davidjames@chromium.org>
diff --git a/buildbot/cbuildbot_stages_unittest.py b/buildbot/cbuildbot_stages_unittest.py
index b344b30..795b24d 100755
--- a/buildbot/cbuildbot_stages_unittest.py
+++ b/buildbot/cbuildbot_stages_unittest.py
@@ -1105,10 +1105,15 @@
 
   def testChromeUpload(self):
     """Test uploading of prebuilts for chrome build."""
-    self.build_config['build_type'] = constants.CHROME_PFQ_TYPE
+    self.options.chrome_rev = None
+    self.build_config = copy.deepcopy(config.config['x86-generic-chromium-pfq'])
     self.RunStage()
+    prefix = ['./upload_prebuilts', '--board', 'x86-generic']
+    self.assertCommandContains(prefix)
+    self.assertCommandContains(prefix + ['--slave-board', 'amd64-generic'])
+    self.assertCommandContains(prefix + ['--slave-board', 'daisy'])
     self.assertCommandContains(['./upload_prebuilts',
-                                self.archive_stage.version])
+                                '--set-version', self.archive_stage.version])
 
   def testPreflightUpload(self):
     """Test uploading of prebuilts for preflight build."""