[Merge M-53] Record and log the use of a profile and/or credit card

components/autofill/core/browser/autofill_data_model.cc

 // 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.
 
 #include "components/autofill/core/browser/autofill_data_model.h"
 
 #include <math.h>
 
 #include "components/autofill/core/browser/autofill_type.h"
 #include "url/gurl.h"
 
 namespace autofill {
 
 AutofillDataModel::AutofillDataModel(const std::string& guid,
                                      const std::string& origin)
     : guid_(guid),
       origin_(origin),
       use_count_(1),
       use_date_(base::Time::Now()),
       modification_date_(base::Time::Now()) {}
 AutofillDataModel::~AutofillDataModel() {}
 
 bool AutofillDataModel::IsVerified() const {
   return !origin_.empty() && !GURL(origin_).is_valid();
 }
 
+// TODO(crbug.com/629507): Add support for injected mock clock for testing.
 void AutofillDataModel::RecordUse() {
   ++use_count_;
   use_date_ = base::Time::Now();
 }
 
 bool AutofillDataModel::CompareFrecency(const AutofillDataModel* other,
                                         base::Time comparison_time) const {
   double score = GetFrecencyScore(comparison_time);
   double other_score = other->GetFrecencyScore(comparison_time);
 
   // Ties are broken by MRU, then by GUID comparison.
   if (score != other_score)
     return score > other_score;
 
   if (use_date_ != other->use_date_)
     return use_date_ > other->use_date_;
 
   return guid_ > other->guid_;
 }
 
 double AutofillDataModel::GetFrecencyScore(base::Time time) const {
   // The formula calculates a score based on both the frequency and the recency
   // of the profile and leveraging the properties of the logarithmic function.
   // DaysSinceLastUse() and |use_count_| are offset because their minimum values
   // are respectively 0 and 1 but the formula requires at least a value of 2.
   return -log((time - use_date_).InDays() + 2) / log(use_count_ + 1);
 }
 
 }  // namespace autofill