commit a03026822db430d22d56982696deda1fd3168e6c
author Marton Hunyady <hunyadym@chromium.org> Wed May 16 18:52:13 2018 +0200
committer chrome-bot <chrome-bot@chromium.org> Wed May 30 20:38:56 2018 -0700
tree ec8510db8f965fbad9cf36709551f9111006f1cb
parent 80f4d4cefb5270960d17cd347d71594e97c7a954

update_engine: Add UMA stats for rollback

Adding the following UMA stats:
- UpdateEngine.Check.TargetVersion: first section of the Chrome OS
  target version set by device policy. Sent during update checks if
  target version policy is set.
- UpdateEngine.Check.RollbackTargetVersion: first section of the
  Chrome OS target version if rollback is also allowed. Sent during
  update checks if both policies are set.
- UpdateEngine.EnterpriseRollback.Success: first section of the
  Chrome OS version to which rollback succeeded. Sent after
  successful installation of the rollback image.
- UpdateEngine.EnterpriseRollback.Failure: first section of the
  Chrome OS version to which rollback failed. Sent after
  installation of the rollback image failed.

Chromium CL of the new histograms: crrev.com/c/1069129

BUG=chromium:843622
TEST='cros_run_unit_tests --board=caroline --packages update_engine'

Change-Id: I0b76fa286498ae0a1830a90034734ed9aa5efd3d
Reviewed-on: https://chromium-review.googlesource.com/1062033
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Marton Hunyady <hunyadym@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>

update_attempter.cc

diff --git a/update_attempter.cc b/update_attempter.cc
index 4a71e4d..67391a3 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -1007,6 +1007,8 @@
       // over the following powerwash.
       if (install_plan.is_rollback) {
         system_state_->payload_state()->SetRollbackHappened(true);
+        system_state_->metrics_reporter()->ReportEnterpriseRollbackMetrics(
+            /*success=*/true, install_plan.version);
       }
 
       // Expect to reboot into the new version to send the proper metric during
@@ -1377,6 +1379,15 @@
   LOG(ERROR) << "Update failed.";
   system_state_->payload_state()->UpdateFailed(error_event_->error_code);
 
+  // Send metrics if it was a rollback.
+  if (response_handler_action_) {
+    const InstallPlan& install_plan = response_handler_action_->install_plan();
+    if (install_plan.is_rollback) {
+      system_state_->metrics_reporter()->ReportEnterpriseRollbackMetrics(
+          /*success=*/false, install_plan.version);
+    }
+  }
+
   // Send it to Omaha.
   LOG(INFO) << "Reporting the error event";
   shared_ptr<OmahaRequestAction> error_event_action(