Adds UMA for days since previous use to help us determine the validity

components/autofill/core/browser/autofill_profile.cc

Index: components/autofill/core/browser/autofill_profile.cc
diff --git a/components/autofill/core/browser/autofill_profile.cc b/components/autofill/core/browser/autofill_profile.cc
index 4ef1222b02a7153bde6d1cdbfb1f74d10adcb606..e54c9fdab7d779a7538e5f10b9283c578f8b3754 100644
--- a/components/autofill/core/browser/autofill_profile.cc
+++ b/components/autofill/core/browser/autofill_profile.cc
@@ -195,23 +195,23 @@ void GetFieldsForDistinguishingProfiles(
 AutofillProfile::AutofillProfile(const std::string& guid,
                                  const std::string& origin)
     : AutofillDataModel(guid, origin),
-      record_type_(LOCAL_PROFILE),
       phone_number_(this),
+      record_type_(LOCAL_PROFILE),
       has_converted_(false) {}
 
 AutofillProfile::AutofillProfile(RecordType type, const std::string& server_id)
     : AutofillDataModel(base::GenerateGUID(), std::string()),
-      record_type_(type),
       phone_number_(this),
       server_id_(server_id),
+      record_type_(type),
       has_converted_(false) {
   DCHECK(type == SERVER_PROFILE);
 }
 
 AutofillProfile::AutofillProfile()
     : AutofillDataModel(base::GenerateGUID(), std::string()),
-      record_type_(LOCAL_PROFILE),
       phone_number_(this),
+      record_type_(LOCAL_PROFILE),
       has_converted_(false) {}
 
 AutofillProfile::AutofillProfile(const AutofillProfile& profile)
@@ -225,6 +225,7 @@ AutofillProfile::~AutofillProfile() {
 AutofillProfile& AutofillProfile::operator=(const AutofillProfile& profile) {
   set_use_count(profile.use_count());
   set_use_date(profile.use_date());
+  set_previous_use_date(profile.previous_use_date());
   set_modification_date(profile.modification_date());
 
   if (this == &profile)
@@ -702,6 +703,7 @@ void AutofillProfile::GenerateServerProfileIdentifier() {
 }
 
 void AutofillProfile::RecordAndLogUse() {
+  previous_use_date_ = use_date();
   UMA_HISTOGRAM_COUNTS_1000("Autofill.DaysSinceLastUse.Profile",
                             (AutofillClock::Now() - use_date()).InDays());
   RecordUse();