Recording in UMA when a user interacted with an address form or a credit card form.

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 92539ba77a68ecf710118bcbc385cd717ee9711c..5eb5fd57d9efd0506932c6455a1a5b1f0d28de52 100644
--- a/components/autofill/core/browser/autofill_metrics.h
+++ b/components/autofill/core/browser/autofill_metrics.h
@@ -243,6 +243,19 @@ class AutofillMetrics {
     NUM_USER_HAPPINESS_METRICS,
   };
 
+  // Form Events for autofill.
+  // These events are triggered separetly for address and credit card forms.
+  enum AutofillFormEvent {
+    // User interacted with a field of this kind of form. Logged only once per
+    // page load.
+    // TODO(waltercacau): All histograms here seem to start with 0,
+    // but the histogram code seems to expect a minimum of 0. Strangely,
+    // they seem to succeed all the assertions as long as there is more then
+    // one enum value.
+    INTERACTED_ONCE = 1,
+    NUM_AUTOFILL_FORM_EVENTS,
+  };
+
   // For measuring the network request time of various Wallet API calls. See
   // WalletClient::RequestType.
   enum WalletApiCallMetric {
@@ -415,6 +428,20 @@ class AutofillMetrics {
   // form.
   static void LogAddressSuggestionsCount(size_t num_suggestions);
 
+  // Utility to autofill form events in the relevant histograms depending on
+  // the presence of server and/or local data.
+  struct FormEventLogger {
+   public:
+    FormEventLogger(
+        bool is_credit_card,
+        bool is_server_data_available,
+        bool is_local_data_available);
+    void Log(AutofillFormEvent event);
+   private:
+    bool is_credit_card_;
+    bool is_server_data_available_;
+    bool is_local_data_available_;
+  };
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AutofillMetrics);
 };