[Dolphin] Add access to the underlying FrecencyStore's data structure.

This adds methods that allow the user of a RecurrenceRanker to mutably
access the storage maps of the ranker's FrecencyStore. This is useful
for custom target/condition deletion logic that cannot be efficiently
implemented via RemoveTarget/Condition.

Bug: 921444
Change-Id: If6add2dee46e6cbd2b0a33820a5e613d5fde3d23
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1669010Reviewed-by: Charles . <charleszhao@chromium.org>
Commit-Queue: Tony Yeoman <tby@chromium.org>
Cr-Commit-Position: refs/heads/master@{#671965}

chrome/browser/ui/app_list/search/search_result_ranker/frecency_store.h

@@ -52,6 +52,13 @@ class FrecencyStore {
   // updated, and none of the scores are below the |min_score_| threshold.
   const base::flat_map<std::string, FrecencyStore::ValueData>& GetAll();
 
+  // Returns the underlying storage data structure. This does not ensure scores
+  // are correct, and should not be used for scoring items. However it is
+  // useful, for example, for implementing custom cleanup logic.
+  base::flat_map<std::string, FrecencyStore::ValueData>* get_mutable_values() {
+    return &values_;
+  }
+
   void ToProto(FrecencyStoreProto* proto) const;
   void FromProto(const FrecencyStoreProto& proto);
 

chrome/browser/ui/app_list/search/search_result_ranker/recurrence_ranker.cc

@@ -18,7 +18,6 @@
 #include "base/task_runner_util.h"
 #include "base/threading/scoped_blocking_call.h"
 #include "chrome/browser/profiles/profile.h"
-#include "chrome/browser/ui/app_list/search/search_result_ranker/frecency_store.h"
 #include "chrome/browser/ui/app_list/search/search_result_ranker/frecency_store.pb.h"
 #include "chrome/browser/ui/app_list/search/search_result_ranker/histogram_util.h"
 #include "chrome/browser/ui/app_list/search/search_result_ranker/recurrence_predictor.h"
@@ -284,6 +283,16 @@ std::vector<std::pair<std::string, float>> RecurrenceRanker::RankTopN(
   return SortAndTruncateRanks(n, Rank(condition));
 }
 
+base::flat_map<std::string, FrecencyStore::ValueData>*
+RecurrenceRanker::GetTargetData() {
+  return targets_->get_mutable_values();
+}
+
+base::flat_map<std::string, FrecencyStore::ValueData>*
+RecurrenceRanker::GetConditionData() {
+  return conditions_->get_mutable_values();
+}
+
 void RecurrenceRanker::SaveToDisk() {
   if (is_ephemeral_user_)
     return;

chrome/browser/ui/app_list/search/search_result_ranker/recurrence_ranker.h

@@ -17,6 +17,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/sequenced_task_runner.h"
 #include "base/time/time.h"
+#include "chrome/browser/ui/app_list/search/search_result_ranker/frecency_store.h"
 #include "chrome/browser/ui/app_list/search/search_result_ranker/recurrence_ranker_config.pb.h"
 
 namespace app_list {
@@ -78,6 +79,12 @@ class RecurrenceRanker {
   // after a target or condition is deleted.
   void SaveToDisk();
 
+  // Return a pointer to the underlying storage of the FrecencyStore for targets
+  // or conditions. These should not be used under normal use or ranking.
+  // However, they are useful for custom cleanup logic.
+  base::flat_map<std::string, FrecencyStore::ValueData>* GetTargetData();
+  base::flat_map<std::string, FrecencyStore::ValueData>* GetConditionData();
+
   const char* GetPredictorNameForTesting() const;
 
  private: