Log observations of explicit UPI-VPA autocomplete hints.

components/autofill/core/browser/autofill_metrics.h

Index: components/autofill/core/browser/autofill_metrics.h
diff --git a/components/autofill/core/browser/autofill_metrics.h b/components/autofill/core/browser/autofill_metrics.h
index d0aba8221f6a042da66e97546fa6324a761df639..7fe9cc45353b7a975f878ab809b21ed616cc2a7d 100644
--- a/components/autofill/core/browser/autofill_metrics.h
+++ b/components/autofill/core/browser/autofill_metrics.h
@@ -90,6 +90,9 @@ class AutofillMetrics {
     // web developer-specified field type hint, a la
     // http://is.gd/whatwg_autocomplete
     FILLABLE_FORM_CONTAINS_TYPE_HINTS,
+    // Parsed a form that is potentially autofillable and contains at least one
+    // UPI Virtual Payment Address hint (upi-vpa)
+    FORM_CONTAINS_UPI_VPA_HINT,
     NUM_DEVELOPER_ENGAGEMENT_METRICS,
   };