[Remote suggestions] Refactor the scheduler

components/ntp_snippets/content_suggestions_service.h

Index: components/ntp_snippets/content_suggestions_service.h
diff --git a/components/ntp_snippets/content_suggestions_service.h b/components/ntp_snippets/content_suggestions_service.h
index b207e065b472820fe6117cb086385d66c4ad46d2..d248009265a7936027d27a820bfff37443298cb4 100644
--- a/components/ntp_snippets/content_suggestions_service.h
+++ b/components/ntp_snippets/content_suggestions_service.h
@@ -24,6 +24,7 @@
 #include "components/ntp_snippets/category_rankers/category_ranker.h"
 #include "components/ntp_snippets/category_status.h"
 #include "components/ntp_snippets/content_suggestions_provider.h"
+#include "components/ntp_snippets/remote/remote_suggestions_scheduler.h"
 #include "components/ntp_snippets/user_classifier.h"
 #include "components/signin/core/browser/signin_manager.h"
 
@@ -33,7 +34,6 @@ class PrefRegistrySimple;
 namespace ntp_snippets {
 
 class RemoteSuggestionsProvider;
-class RemoteSuggestionsScheduler;
 
 // Retrieves suggestions from a number of ContentSuggestionsProviders and serves
 // them grouped into categories. There can be at most one provider per category.
@@ -225,11 +225,12 @@ class ContentSuggestionsService : public KeyedService,
   // factory. The interface is suited for informing about external events that
   // have influence on scheduling remote fetches.
   void set_remote_suggestions_scheduler(
-      ntp_snippets::RemoteSuggestionsScheduler* remote_suggestions_scheduler) {
-    remote_suggestions_scheduler_ = remote_suggestions_scheduler;
+      std::unique_ptr<ntp_snippets::RemoteSuggestionsScheduler>
+          remote_suggestions_scheduler) {
+    remote_suggestions_scheduler_ = std::move(remote_suggestions_scheduler);
   }
   RemoteSuggestionsScheduler* remote_suggestions_scheduler() {
-    return remote_suggestions_scheduler_;
+    return remote_suggestions_scheduler_.get();
   }
 
   UserClassifier* user_classifier() { return &user_classifier_; }
@@ -341,8 +342,9 @@ class ContentSuggestionsService : public KeyedService,
   RemoteSuggestionsProvider* remote_suggestions_provider_;
 
   // Interface for informing about external events that have influence on
-  // scheduling remote fetches. Not owned.
-  RemoteSuggestionsScheduler* remote_suggestions_scheduler_;
+  // scheduling remote fetches.
+  std::unique_ptr<ntp_snippets::RemoteSuggestionsScheduler>
+      remote_suggestions_scheduler_;
 
   PrefService* pref_service_;