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..893c6d4bd5da2402b6ebd9c9e1a3e700bc493c09 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 {
@@ -704,18 +706,33 @@ void AutofillMetrics::LogCardUploadDecisionUkm(
   if (upload_decision >= AutofillMetrics::NUM_CARD_UPLOAD_DECISION_METRICS)
     return;
 
-  // Set up as a map because the follow-up CL will add more metrics.
-  std::map<std::string, int> metrics = {
+  const std::vector<std::pair<const char*, int>> metrics = {
       {internal::kUKMCardUploadDecisionMetricName,
        static_cast<int>(upload_decision)}};
   LogUkm(ukm_service, url, internal::kUKMCardUploadDecisionEntryName, metrics);
 }
 
 // static
-bool AutofillMetrics::LogUkm(ukm::UkmService* ukm_service,
-                             const GURL& url,
-                             const std::string& ukm_entry_name,
-                             const std::map<std::string, int>& metrics) {
+void AutofillMetrics::LogDeveloperEngagementUkm(
+    ukm::UkmService* ukm_service,
+    const GURL& url,
+    const std::vector<AutofillMetrics::DeveloperEngagementMetric>& metrics) {
+  std::vector<std::pair<const char*, int>> form_structure_metrics;
+  for (auto it = metrics.begin(); it != metrics.end(); ++it) {
+    if (*it < AutofillMetrics::NUM_DEVELOPER_ENGAGEMENT_METRICS)
+      form_structure_metrics.emplace_back(std::make_pair(
+          internal::kUKMDeveloperEngagementMetricName, static_cast<int>(*it)));
+  }
+  LogUkm(ukm_service, url, internal::kUKMDeveloperEngagementEntryName,
+         form_structure_metrics);
+}
+
+// static
+bool AutofillMetrics::LogUkm(
+    ukm::UkmService* ukm_service,
+    const GURL& url,
+    const std::string& ukm_entry_name,
+    const std::vector<std::pair<const char*, int>>& metrics) {
   if (!IsUkmLoggingEnabled() || !ukm_service || !url.is_valid() ||
       metrics.empty()) {
     return false;
@@ -727,7 +744,7 @@ bool AutofillMetrics::LogUkm(ukm::UkmService* ukm_service,
       ukm_service->GetEntryBuilder(source_id, ukm_entry_name.c_str());
 
   for (auto it = metrics.begin(); it != metrics.end(); ++it) {
-    builder->AddMetric(it->first.c_str(), it->second);
+    builder->AddMetric(it->first, it->second);
   }
 
   return true;