[CrOS PhoneHub] Add metrics for tether connection result.

Bug: 1150634
Change-Id: I84ad38c9eb8af368c0c34ba56305da0088d121ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2568364
Commit-Queue: Meilin Wang <meilinw@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833883}

chromeos/components/phonehub/tether_controller_impl.cc

@@ -6,6 +6,7 @@
 
 #include "chromeos/components/multidevice/logging/logging.h"
 #include "chromeos/components/phonehub/phone_status_model.h"
+#include "chromeos/components/phonehub/util/histogram_util.h"
 #include "chromeos/services/network_config/in_process_instance.h"
 
 namespace chromeos {
@@ -113,6 +114,8 @@ void TetherControllerImpl::AttemptConnection() {
   }
 
   PA_LOG(INFO) << "Attempting connection; current status is " << status_;
+  util::LogTetherConnectionResult(
+      util::TetherConnectionResult::kAttemptConnection);
 
   FeatureState feature_state =
       multidevice_setup_client_->GetFeatureState(Feature::kInstantTethering);
@@ -383,6 +386,11 @@ void TetherControllerImpl::UpdateStatus() {
 
   PA_LOG(INFO) << "TetherController status update: " << status_ << " => "
                << status;
+
+  // Log the connection attempt result if it has succeed.
+  if (status == Status::kConnected)
+    util::LogTetherConnectionResult(util::TetherConnectionResult::kSuccess);
+
   status_ = status;
 
   NotifyStatusChanged();

chromeos/components/phonehub/util/histogram_util.cc

@@ -4,14 +4,19 @@
 
 #include "chromeos/components/phonehub/util/histogram_util.h"
 
-#include "base/metrics/histogram_macros.h"
+#include "base/metrics/histogram_functions.h"
 
 namespace chromeos {
 namespace phonehub {
 namespace util {
 
 void LogFeatureOptInEntryPoint(OptInEntryPoint entry_point) {
-  UMA_HISTOGRAM_ENUMERATION("PhoneHub.OptInEntryPoint", entry_point);
+  base::UmaHistogramEnumeration("PhoneHub.OptInEntryPoint", entry_point);
+}
+
+void LogTetherConnectionResult(TetherConnectionResult result) {
+  base::UmaHistogramEnumeration(
+      "PhoneHub.TaskCompletion.TetherConnection.Result", result);
 }
 
 }  // namespace util

chromeos/components/phonehub/util/histogram_util.h

@@ -20,9 +20,19 @@ enum class OptInEntryPoint {
   kMaxValue = kSettings,
 };
 
+// Enumeration of results of a tethering connection attempt.
+enum class TetherConnectionResult {
+  kAttemptConnection = 0,
+  kSuccess = 1,
+  kMaxValue = kSuccess,
+};
+
 // Logs a given opt-in |entry_point| for the PhoneHub feature.
 void LogFeatureOptInEntryPoint(OptInEntryPoint entry_point);
 
+// Logs a given |result| of a tethering connection attempt.
+void LogTetherConnectionResult(TetherConnectionResult result);
+
 }  // namespace util
 }  // namespace phonehub
 }  // namespace chromeos

tools/metrics/histograms/enums.xml

@@ -58304,6 +58304,11 @@ Called by update_net_trust_anchors.py.-->
   <int value="9" label="PhoneConnecting"/>
 </enum>
 
+<enum name="PhoneHubTetherConnectionResult">
+  <int value="0" label="Started a tether connection attempt"/>
+  <int value="1" label="Attempt was successful"/>
+</enum>
+
 <enum name="PhoneNumberRegexVariantResult">
   <obsolete>
     Removed in M82 as the experiment has been stopped.

tools/metrics/histograms/histograms_xml/phonehub/histograms.xml

@@ -171,6 +171,16 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   </summary>
 </histogram>
 
+<histogram name="PhoneHub.TaskCompletion.TetherConnection.Result"
+    enum="PhoneHubTetherConnectionResult" expires_after="2021-12-01">
+  <owner>khorimoto@chromium.org</owner>
+  <owner>phonehub-dev@google.com</owner>
+  <summary>
+    Logs the result of attempting a tether connection to measure the connection
+    success rate.
+  </summary>
+</histogram>
+
 <histogram name="PhoneHub.Usage.SentMessageTypeCount"
     enum="PhoneHubMessageType" expires_after="M98">
   <owner>khorimoto@chromium.org</owner>