Set site engagement timestamps to privacy-respectful values when history is cleared.

chrome/browser/engagement/site_engagement_service.h

 // Copyright 2015 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 CHROME_BROWSER_ENGAGEMENT_SITE_ENGAGEMENT_SERVICE_H_
 #define CHROME_BROWSER_ENGAGEMENT_SITE_ENGAGEMENT_SERVICE_H_
 
 #include <map>
 #include <set>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "chrome/browser/engagement/site_engagement_metrics.h"
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "ui/base/page_transition_types.h"
 
 namespace base {
 class DictionaryValue;
 class Clock;
 }
 
+namespace history {
+class HistoryService;
+}
+
 class GURL;
 class Profile;
 
 class SiteEngagementScore {
  public:
   // The parameters which can be varied via field trial. All "points" values
   // should be appended to the end of the enum prior to MAX_VARIATION.
   enum Variation {
     // The maximum number of points that can be accrued in one day.
     MAX_POINTS_PER_DAY = 0,
@@ skipping 59 matching lines @@
   // The SiteEngagementService does not take ownership of |clock|. It is the
   // responsibility of the caller to make sure |clock| outlives this
   // SiteEngagementScore.
   SiteEngagementScore(base::Clock* clock,
                       const base::DictionaryValue& score_dict);
   ~SiteEngagementScore();
 
   double Score() const;
   void AddPoints(double points);
 
-  // Resets the score to |points| and reset the daily point limit.
-  void Reset(double points);
+  // Resets the score to |points| and resets the daily point limit. If
+  // |updated_time| is non-null, sets the last engagement time and last
+  // shortcut launch time (if it is non-null) to |updated_time|. Otherwise, last
+  // engagement time is set to the current time and last shortcut launch time is
+  // left unchanged.
+  // TODO(calamity): Ideally, all SiteEngagementScore methods should take a
+  // base::Time argument like this one does rather than each Score hold a
+  // pointer to a base::Clock. Then SiteEngagementScore doesn't need to worry
+  // about clock vending. See crbug.com/604305
+  void Reset(double points, const base::Time* updated_time);
 
   // Returns true if the maximum number of points today has been added.
   bool MaxPointsPerDayAdded() const;
 
   // Get/set the last time this origin was launched from an installed shortcut.
   base::Time last_shortcut_launch_time() const {
     return last_shortcut_launch_time_;
   }
   void set_last_shortcut_launch_time(const base::Time& time) {
     last_shortcut_launch_time_ = time;
@@ skipping 175 matching lines @@
   void RecordMetrics();
 
   // Returns the median engagement score of all recorded origins.
   double GetMedianEngagement(const std::map<GURL, double>& score_map) const;
 
   // Returns the number of origins with maximum daily and total engagement
   // respectively.
   int OriginsWithMaxDailyEngagement() const;
   int OriginsWithMaxEngagement(const std::map<GURL, double>& score_map) const;
 
-  void GetCountsForOriginsComplete(
+  void GetCountsAndLastVisitForOriginsComplete(
+    history::HistoryService* history_service,
     const std::multiset<GURL>& deleted_url_origins,
     bool expired,
-    const history::OriginCountMap& remaining_origin_counts);
+    const history::OriginCountAndLastVisitMap& remaining_origin_counts);
+
+  // Resets the engagement score for |url| to |score|, and sets the last
+  // engagement time and last shortcut launch time (if it is non-null) to
+  // |updated_time|. Clears daily limits.
+  void ResetScoreAndAccessTimesForURL(const GURL& url,
+                                      double score,
+                                      const base::Time* updated_time);
 
   Profile* profile_;
 
   // The clock used to vend times.
   scoped_ptr<base::Clock> clock_;
 
   // Metrics are recorded at non-incognito browser startup, and then
   // approximately once per hour thereafter. Store the local time at which
   // metrics were previously uploaded: the first event which affects any
   // origin's engagement score after an hour has elapsed triggers the next
   // upload.
   base::Time last_metrics_time_;
 
   base::WeakPtrFactory<SiteEngagementService> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SiteEngagementService);
 };
 
 #endif  // CHROME_BROWSER_ENGAGEMENT_SITE_ENGAGEMENT_SERVICE_H_