Fix goma_artifacts output proto update for stats/counterz.

Add info logging around stats/counterz file copying.

BUG=chromium:1013499
TEST=run_tests

Change-Id: I08046d1915f1c31691ff089e11c2ec80f5b78778
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2020465
Tested-by: Michael Mortensen <mmortensen@google.com>
Reviewed-by: Alex Klein <saklein@chromium.org>
Commit-Queue: Michael Mortensen <mmortensen@google.com>
diff --git a/api/controller/sysroot_unittest.py b/api/controller/sysroot_unittest.py
index 6d230ec..94fe3dd 100644
--- a/api/controller/sysroot_unittest.py
+++ b/api/controller/sysroot_unittest.py
@@ -542,6 +542,10 @@
         'compiler_proxy-subproc.host.log.INFO.20180921-120100.000000.gz',
         'compiler_proxy.host.log.INFO.20180921-120000.000000.gz',
         'gomacc.host.log.INFO.20180921-120200.000000.tar.gz'])
+    self.assertEqual(out_proto.goma_artifacts.counterz_file,
+                     'counterz.binaryproto')
+    self.assertEqual(out_proto.goma_artifacts.stats_file,
+                     'stats.binaryproto')
 
   def testFailureMissingGomaStatsCounterzFiles(self):
     """Test successful call with goma including stats and counterz files."""