Collecting UMA metrics for the UnmaskPrompt.

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 78540dc4127fcf47760472d4b5302386781ac989..5e25be977e10daf5a142d24170480fc9dd1ba22f 100644
--- a/components/autofill/core/browser/autofill_metrics.h
+++ b/components/autofill/core/browser/autofill_metrics.h
@@ -284,6 +284,39 @@ class AutofillMetrics {
     NUM_FORM_EVENTS,
   };
 
+  // Events related to the Unmask Credit Card Prompt.
+  enum UnmaskPromptEvent {
+    // The prompt was shown.
+    UNMASK_PROMPT_SHOWN = 0,
+    // The prompt was closed without attempting to unmask the card.
+    UNMASK_PROMPT_CLOSED_NO_ATTEMPTS,
+    // The prompt was closed without unmasking the card, but with at least
+    // one attempt. The last failure was retriable.
+    UNMASK_PROMPT_CLOSED_FAILED_TO_UNMASK_RETRIABLE_FAILURE,
+    // The prompt was closed without unmasking the card, but with at least
+    // one attempt. The last failure was non retriable.
+    UNMASK_PROMPT_CLOSED_FAILED_TO_UNMASK_NON_RETRIABLE_FAILURE,
+    // Successfully unmasked the card in the first attempt.
+    UNMASK_PROMPT_UNMASKED_CARD_FIRST_ATTEMPT,
+    // Successfully unmasked the card after retriable failures.
+    UNMASK_PROMPT_UNMASKED_CARD_AFTER_FAILED_ATTEMPTS,
+    // Saved the card locally (masked card was upgraded to a full card).
+    UNMASK_PROMPT_SAVED_CARD_LOCALLY,
+    // User chose to opt in (checked the checkbox when it was empty).
+    // Only logged if there was an attempt to unmask.
+    UNMASK_PROMPT_LOCAL_SAVE_DID_OPT_IN,
+    // User did not opt in when he had the chance (left the checkbox unchecked).
+    // Only logged if there was an attempt to unmask.
+    UNMASK_PROMPT_LOCAL_SAVE_DID_NOT_OPT_IN,
+    // User chose to opt out (unchecked the checkbox when it was check).
+    // Only logged if there was an attempt to unmask.
+    UNMASK_PROMPT_LOCAL_SAVE_DID_OPT_OUT,
+    // User did not opt out when he had a chance (left the checkbox checked).
+    // Only logged if there was an attempt to unmask.
+    UNMASK_PROMPT_LOCAL_SAVE_DID_NOT_OPT_OUT,
+    NUM_UNMASK_PROMPT_EVENTS,
+  };
+
   // For measuring the network request time of various Wallet API calls. See
   // WalletClient::RequestType.
   enum WalletApiCallMetric {
@@ -410,6 +443,9 @@ class AutofillMetrics {
   // Logs |event| to the UI events histogram.
   static void LogDialogUiEvent(DialogUiEvent event);
 
+  // Logs |event| to the unmask prompt events histogram.
+  static void LogUnmaskPromptEvent(UnmaskPromptEvent event);
+
   // Logs |metric| to the Wallet errors histogram.
   static void LogWalletErrorMetric(WalletErrorMetric metric);