OOBE - Marketing - Combine marketing metrics

Generate an additional metric that combines data from
all countries for the Chromebook marketing opt-in.

Fixed: 1136816
Change-Id: I521824b2b5f7d5c06402dad5ccbe1719dd1c197d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2463613
Commit-Queue: Renato Silva <rrsilva@google.com>
Commit-Queue: Denis Kuznetsov [CET] <antrim@chromium.org>
Auto-Submit: Renato Silva <rrsilva@google.com>
Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816168}

chrome/browser/chromeos/login/marketing_backend_connector.cc

@@ -54,6 +54,10 @@ void RecordUMAHistogram(MarketingBackendConnector::BackendConnectorEvent event,
                         const std::string& country) {
   base::UmaHistogramEnumeration(
       "OOBE.MarketingOptInScreen.BackendConnector." + country, event);
+
+  // Generic event aggregating data from all countries.
+  base::UmaHistogramEnumeration("OOBE.MarketingOptInScreen.BackendConnector",
+                                event);
 }
 
 std::unique_ptr<network::ResourceRequest> GetResourceRequest() {

chrome/browser/chromeos/login/screens/marketing_opt_in_screen.cc

@@ -58,6 +58,8 @@ void RecordOptInAndOptOutRates(const bool user_opted_in,
 
   base::UmaHistogramEnumeration("OOBE.MarketingOptInScreen.Event." + country,
                                 event);
+  // Generic event aggregating data from all countries.
+  base::UmaHistogramEnumeration("OOBE.MarketingOptInScreen.Event", event);
 }
 
 void RecordGeolocationResolve(MarketingOptInScreen::GeolocationEvent event) {

chrome/browser/chromeos/login/screens/marketing_opt_in_screen_browsertest.cc

@@ -408,12 +408,16 @@ IN_PROC_BROWSER_TEST_P(MarketingTestCountryCodes, CountryCodes) {
   TapOnGetStartedAndWaitForScreenExit();
   WaitForBackendRequest();
   EXPECT_EQ(GetRequestedCountryCode(), param.country_code);
-  histogram_tester_.ExpectUniqueSample(
-      "OOBE.MarketingOptInScreen.Event." + std::string(param.country_code),
+  const auto event =
       (param.is_default_opt_in)
           ? MarketingOptInScreen::Event::kUserOptedInWhenDefaultIsOptIn
-          : MarketingOptInScreen::Event::kUserOptedInWhenDefaultIsOptOut,
-      1);
+          : MarketingOptInScreen::Event::kUserOptedInWhenDefaultIsOptOut;
+  histogram_tester_.ExpectUniqueSample(
+      "OOBE.MarketingOptInScreen.Event." + std::string(param.country_code),
+      event, 1);
+  // Expect a generic event in addition to the country specific one.
+  histogram_tester_.ExpectUniqueSample("OOBE.MarketingOptInScreen.Event", event,
+                                       1);
 
   // Expect successful geolocation resolve.
   ExpectGeolocationMetric(true, std::string(param.country_code).size());