commit 96197df73f6c804d96eb3a1390eb817f354089d2
author David Zeuthen <zeuthen@chromium.org> Wed Apr 16 12:22:39 2014 -0700
committer chrome-internal-fetch <chrome-internal-fetch@google.com> Thu Apr 17 16:39:16 2014 +0000
tree 08ba33cb0476a51fe82c9ad8cf95624634a9cf3f
parent afed4a1a355c8416d496901234932e99864d6215

metrics: Add UpdateEngine.Rollback.Result metric.

Add a metric to track if rollback succeeds or fails. The main use case
for this metric is to record how often rollback actually happens.

Right now we only track success/failure but if we see a lot of
failures in the future, we could add a new metric, for example

 UpdateEngine.Rollback.FailureErrorCode

to convey more detail.

BUG=None
TEST=New unit test + unit tests pass.

Change-Id: I5c32d8585dc8e4b6d38c540d2f754ede5b2ad50b
Reviewed-on: https://chromium-review.googlesource.com/195203
Reviewed-by: David Zeuthen <zeuthen@chromium.org>
Commit-Queue: David Zeuthen <zeuthen@chromium.org>
Tested-by: David Zeuthen <zeuthen@chromium.org>

payload_state_unittest.cc

diff --git a/payload_state_unittest.cc b/payload_state_unittest.cc
index 11eb4af..24aa070 100644
--- a/payload_state_unittest.cc
+++ b/payload_state_unittest.cc
@@ -1081,11 +1081,17 @@
   payload_state.LoadRollbackVersion();
   EXPECT_EQ(rollback_version, payload_state.GetRollbackVersion());
 
-  // Check that we don't report any metrics in UpdateSucceeded().
+  // Check that we report only UpdateEngine.Rollback.* metrics in
+  // UpdateSucceeded().
   EXPECT_CALL(*fake_system_state.mock_metrics_lib(), SendToUMA(_, _, _, _, _))
     .Times(0);
   EXPECT_CALL(*fake_system_state.mock_metrics_lib(), SendEnumToUMA(_, _, _))
     .Times(0);
+  EXPECT_CALL(*fake_system_state.mock_metrics_lib(),
+              SendEnumToUMA(
+                  metrics::kMetricRollbackResult,
+                  static_cast<int>(metrics::RollbackResult::kSuccess),
+                  static_cast<int>(metrics::RollbackResult::kNumConstants)));
   payload_state.UpdateSucceeded();
 }