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

components/autofill/core/browser/autofill_profile.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_PROFILE_H_
 #define COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_PROFILE_H_
 
 #include <stddef.h>
 
 #include <iosfwd>
 #include <list>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/strings/string16.h"
+#include "base/time/time.h"
 #include "components/autofill/core/browser/address.h"
 #include "components/autofill/core/browser/autofill_data_model.h"
 #include "components/autofill/core/browser/autofill_type.h"
 #include "components/autofill/core/browser/contact_info.h"
 #include "components/autofill/core/browser/phone_number.h"
 
 namespace autofill {
 
 // A collection of FormGroups stored in a profile.  AutofillProfile also
 // implements the FormGroup interface so that owners of this object can request
@@ skipping 140 matching lines @@
 
   // Nonempty only when type() == SERVER_PROFILE. base::kSHA1Length bytes long.
   // Not necessarily valid UTF-8.
   const std::string& server_id() const { return server_id_; }
 
   // Creates an identifier and saves it as |server_id_|. Only used for
   // server credit cards. The server doesn't attach an identifier so Chrome
   // creates its own. The ID is a hash of the data contained in the profile.
   void GenerateServerProfileIdentifier();
 
-  // Logs the number of days since the profile was last used and records its
-  // use.
+  // Logs the number of days since the profile was last used, records its
+  // use and updates |previous_use_date_| to time it was previously used.

[sebsg, 2017/05/08 21:43:29]

nit: and updates |previous_use_date_| to the last value of |use_date_|/

[csashi, 2017/05/08 21:51:41]

Done.

   void RecordAndLogUse();
 
-  // Valid only when type() == SERVER_PROFILE.
+  const base::Time& previous_use_date() const { return previous_use_date_; }
+  void set_previous_use_date(const base::Time& time) {
+    previous_use_date_ = time;
+  }
+
+  // Valid only when |record_type()| == |SERVER_PROFILE|.
   bool has_converted() const { return has_converted_; }
   void set_has_converted(bool has_converted) { has_converted_ = has_converted; }
 
  private:
   typedef std::vector<const FormGroup*> FormGroupList;
 
   // FormGroup:
   void GetSupportedTypes(ServerFieldTypeSet* supported_types) const override;
 
   // Creates inferred labels for |profiles| at indices corresponding to
@@ skipping 11 matching lines @@
 
   // Utilities for listing and lookup of the data members that constitute
   // user-visible profile information.
   FormGroupList FormGroups() const;
   const FormGroup* FormGroupForType(const AutofillType& type) const;
   FormGroup* MutableFormGroupForType(const AutofillType& type);
 
   // Same as operator==, but ignores differences in GUID.
   bool EqualsSansGuid(const AutofillProfile& profile) const;
 
-  RecordType record_type_;
-
   // Personal information for this profile.
   NameInfo name_;
   EmailInfo email_;
   CompanyInfo company_;
   PhoneNumber phone_number_;
   Address address_;
 
   // The BCP 47 language code that can be used to format |address_| for display.
   std::string language_code_;
 
   // ID used for identifying this profile. Only set for SERVER_PROFILEs. This is
   // a hash of the contents.
   std::string server_id_;
 
+  // Penultimate time model was used.
+  base::Time previous_use_date_;

[sebsg, 2017/05/08 21:43:29]

Could you add a comment here, saying that this value is not preserved when
Chrome is closed?

[csashi, 2017/05/08 21:51:41]

Done.

+
+  RecordType record_type_;

[sebsg, 2017/05/08 21:43:29]

Is there a particular reason why you moved it down?

[csashi, 2017/05/08 21:51:41]

https://bugs.chromium.org/p/chromium/issues/detail?id=710933
This is not an issue for this struct because we have very few profiles - still,
when we can improve padding why not?

[sebsg, 2017/05/08 21:54:19]

Ah sweet, thank for the info.

+
   // Only useful for SERVER_PROFILEs. Whether this server profile has been
   // converted to a local profile.
   bool has_converted_;
 };
 
 // So we can compare AutofillProfiles with EXPECT_EQ().
 std::ostream& operator<<(std::ostream& os, const AutofillProfile& profile);
 
 }  // namespace autofill
 
 #endif  // COMPONENTS_AUTOFILL_CORE_BROWSER_AUTOFILL_PROFILE_H_