Logs different SaveCardPrompt histogram names depending on if user

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 77442395f201073a68feac7dc21890f545343393..c25988fbb571ce78e3067b2fc9e21cccd704879a 100644
--- a/components/autofill/core/browser/autofill_metrics.cc
+++ b/components/autofill/core/browser/autofill_metrics.cc
@@ -80,6 +80,20 @@ enum FieldTypeGroupForMetrics {
   NUM_FIELD_TYPE_GROUPS_FOR_METRICS
 };
 
+std::string PreviousSaveCreditCardPromptUserDecisionToString(
+    int previous_save_credit_card_prompt_user_decision) {
+  DCHECK_LT(previous_save_credit_card_prompt_user_decision,
+            prefs::NUM_PREVIOUS_SAVE_CREDIT_CARD_PROMPT_USER_DECISIONS);
+  std::string previous_response;
+  if (previous_save_credit_card_prompt_user_decision ==
+      prefs::PREVIOUS_SAVE_CREDIT_CARD_PROMPT_USER_DECISION_ACCEPTED)
+    previous_response = ".PreviouslyAccepted";
+  else if (previous_save_credit_card_prompt_user_decision ==
+           prefs::PREVIOUS_SAVE_CREDIT_CARD_PROMPT_USER_DECISION_DENIED)
+    previous_response = ".PreviouslyDenied";
+  return previous_response;

[Mark P, 2017/04/27 22:52:58]

optional nit while I'm here:
DCHECK_EQ(PREVIOUS_SAVE_CREDIT_CARD_PROMPT_USER_DECISION_NONE,
previous_save_credit_card_prompt_user_decision);

[csashi, 2017/04/27 23:37:51]

Done.

+}
+
 }  // namespace
 
 // First, translates |field_type| to the corresponding logical |group| from
@@ -298,16 +312,18 @@ void AutofillMetrics::LogCardUploadDecisionMetric(
 }
 
 // static
-void AutofillMetrics::LogCreditCardInfoBarMetric(InfoBarMetric metric,
-                                                 bool is_uploading) {
+void AutofillMetrics::LogCreditCardInfoBarMetric(
+    InfoBarMetric metric,
+    bool is_uploading,
+    int previous_save_credit_card_prompt_user_decision) {
   DCHECK_LT(metric, NUM_INFO_BAR_METRICS);
-  if (is_uploading) {
-    UMA_HISTOGRAM_ENUMERATION("Autofill.CreditCardInfoBar.Server", metric,
-                              NUM_INFO_BAR_METRICS);
-  } else {
-    UMA_HISTOGRAM_ENUMERATION("Autofill.CreditCardInfoBar.Local", metric,
-                              NUM_INFO_BAR_METRICS);
-  }
+
+  std::string destination = is_uploading ? ".Server" : ".Local";
+  LogUMAHistogramEnumeration(
+      "Autofill.CreditCardInfoBar" + destination +
+          PreviousSaveCreditCardPromptUserDecisionToString(

[Mark P, 2017/04/27 22:52:58]

This structure makes is to there is no longer a single summary metric regardless
of a previous decision.  You only have three sliced metrics (previously
accepted, previously denied, nothing previous).  There is no way to view the
aggregate without manually adding up those separate histograms.  Please consider
whether viewing the aggregate would be useful.

(I imagine so, but I won't force you to do if you don't think so.)

Ditto with all changes below.

[csashi, 2017/04/27 23:37:51]

It is useful to view the aggregate but I would rather burden the downstream
analysis tools rather than Chrome client. Also, it is consistent with other
stats I have seen. For example, FORM_EVENT_LOCAL_SUGGESTION_FILLED, 
FORM_EVENT_SERVER_SUGGESTION_FILLED and
FORM_EVENT_MASKED_SERVER_CARD_SUGGESTION_FILLED all refer to different types of
suggestion fills and we aggregate it on the analysis side to compute suggestion
usage rate.

+              previous_save_credit_card_prompt_user_decision),
+      metric, NUM_INFO_BAR_METRICS);
 }
 
 // static
@@ -318,15 +334,19 @@ void AutofillMetrics::LogCreditCardFillingInfoBarMetric(InfoBarMetric metric) {
 }
 
 // static
-void AutofillMetrics::LogSaveCardPromptMetric(SaveCardPromptMetric metric,
-                                              bool is_uploading,
-                                              bool is_reshow) {
+void AutofillMetrics::LogSaveCardPromptMetric(
+    SaveCardPromptMetric metric,
+    bool is_uploading,
+    bool is_reshow,
+    int previous_save_credit_card_prompt_user_decision) {
   DCHECK_LT(metric, NUM_SAVE_CARD_PROMPT_METRICS);
   std::string destination = is_uploading ? ".Upload" : ".Local";
   std::string show = is_reshow ? ".Reshows" : ".FirstShow";
   LogUMAHistogramEnumeration(
-      "Autofill.SaveCreditCardPrompt" + destination + show, metric,
-      NUM_SAVE_CARD_PROMPT_METRICS);
+      "Autofill.SaveCreditCardPrompt" + destination + show +
+          PreviousSaveCreditCardPromptUserDecisionToString(
+              previous_save_credit_card_prompt_user_decision),
+      metric, NUM_SAVE_CARD_PROMPT_METRICS);
 }
 
 // static