Delete unmasked credit cards when clearing data.

components/autofill/core/browser/webdata/autofill_table.h

Index: components/autofill/core/browser/webdata/autofill_table.h
diff --git a/components/autofill/core/browser/webdata/autofill_table.h b/components/autofill/core/browser/webdata/autofill_table.h
index 3f8093c909b8498b0ad771ef01a5588b97cd2d5e..6b8250ba9e390780167886d7cefc057424f2adf8 100644
--- a/components/autofill/core/browser/webdata/autofill_table.h
+++ b/components/autofill/core/browser/webdata/autofill_table.h
@@ -167,6 +167,8 @@ struct FormFieldData;
 //                      a form. Added in version 62.
 //   use_date           The date this card was last used to fill a form, in
 //                      internal time format (NOT time_t). Added in version 62.
+//   unmask_date        The date this card was unmasked in units of
+//                      Time::ToInternalValue. Added in version 64.
 //
 // server_addresses     This table contains Autofill address data synced from
 //                      the wallet server. It's basically the same as the
@@ -366,6 +368,7 @@ class AutofillTable : public WebDatabaseTable {
   bool MigrateToVersion61AddUsageStats();
   bool MigrateToVersion62AddUsageStatsForUnmaskedCards();
   bool MigrateToVersion63AddServerRecipientName();
+  bool MigrateToVersion64AddUnmaskDate();
 
   // Max data length saved in the table;
   static const size_t kMaxDataLength;