Adds UKM for autofill attributes in form_structure.

components/autofill/core/browser/autofill_metrics.cc

Index: components/autofill/core/browser/autofill_metrics.cc
diff --git a/components/autofill/core/browser/autofill_metrics.cc b/components/autofill/core/browser/autofill_metrics.cc
index 239334c5e660612da4f9da3d85384c3f663ff38e..bc30e682ee8c006aaa8784e9cf74cd7b09548859 100644
--- a/components/autofill/core/browser/autofill_metrics.cc
+++ b/components/autofill/core/browser/autofill_metrics.cc
@@ -20,6 +20,8 @@
 namespace internal {
 const char kUKMCardUploadDecisionEntryName[] = "Autofill.CardUploadDecision";
 const char kUKMCardUploadDecisionMetricName[] = "UploadDecision";
+const char kUKMDeveloperEngagementEntryName[] = "Autofill.DeveloperEngagement";
+const char kUKMDeveloperEngagementMetricName[] = "DeveloperEngagement";
 }  // namespace internal
 
 namespace autofill {
@@ -712,6 +714,21 @@ void AutofillMetrics::LogCardUploadDecisionUkm(
 }
 
 // static
+void AutofillMetrics::LogDeveloperEngagementUkm(
+    ukm::UkmService* ukm_service,
+    const GURL& url,
+    AutofillMetrics::DeveloperEngagementMetric form_structure_metric) {
+  if (form_structure_metric >=
+      AutofillMetrics::NUM_DEVELOPER_ENGAGEMENT_METRICS)
+    return;
+
+  std::map<std::string, int> metrics = {
+      {internal::kUKMDeveloperEngagementMetricName,
+       static_cast<int>(form_structure_metric)}};
+  LogUkm(ukm_service, url, internal::kUKMDeveloperEngagementEntryName, metrics);
+}
+
+// static
 bool AutofillMetrics::LogUkm(ukm::UkmService* ukm_service,
                              const GURL& url,
                              const std::string& ukm_entry_name,