Log observations of explicit UPI-VPA autocomplete hints.

components/autofill/core/browser/autofill_metrics_unittest.cc

Index: components/autofill/core/browser/autofill_metrics_unittest.cc
diff --git a/components/autofill/core/browser/autofill_metrics_unittest.cc b/components/autofill/core/browser/autofill_metrics_unittest.cc
index efea6e76cab0aafd11a2a5053fff1cb525bda757..01b1b23e3aae8ac840727cace9647988b5305068 100644
--- a/components/autofill/core/browser/autofill_metrics_unittest.cc
+++ b/components/autofill/core/browser/autofill_metrics_unittest.cc
@@ -4366,6 +4366,18 @@ TEST_F(AutofillMetricsTest,
   }
 }
 
+// Tests that logging an explicit UPI-VPA hint works as expected.
+TEST_F(AutofillMetricsTest, LogExplicitUpiVpaHint) {
+  constexpr int kNumHints = 5;
+  base::HistogramTester histograms;
+  for (int i = 0; i < kNumHints; ++i)
+    AutofillMetrics::LogExplicitUpiVpaHint();
+  histograms.ExpectBucketCount("Autofill.ExplicitUpiVpaHint",
+                               static_cast<int>(false), 0);
+  histograms.ExpectBucketCount("Autofill.ExplicitUpiVpaHint",
+                               static_cast<int>(true), kNumHints);
+}
+
 // Tests that logging a UKM works as expected.
 TEST_F(AutofillMetricsTest, RecordCardUploadDecisionMetric) {
   EnableUkmLogging();