[Offline Pages] Use existing function to get persistent namespaces.

In StartupMaintenanceTask and PersistentPageConsistencyCheckTask, there
was a step to get persistent/temporary namespaces, which didn't use the
existing function. This CL fixed it.

Bug: NONE
Change-Id: I7b4a1f6255003886917790dff875c20b43cfc032
Reviewed-on: https://chromium-review.googlesource.com/1027111Reviewed-by: Cathy Li <chili@chromium.org>
Commit-Queue: Yafei Duan <romax@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553430}

components/offline_pages/core/model/persistent_page_consistency_check_task.cc

@@ -220,12 +220,8 @@ PersistentPageConsistencyCheckTask::~PersistentPageConsistencyCheckTask() =
     default;
 
 void PersistentPageConsistencyCheckTask::Run() {
-  std::vector<std::string> namespaces = policy_controller_->GetAllNamespaces();
-  std::vector<std::string> persistent_namespaces;
-  for (const auto& name_space : namespaces) {
-    if (!policy_controller_->IsRemovedOnCacheReset(name_space))
-      persistent_namespaces.push_back(name_space);
-  }
+  std::vector<std::string> persistent_namespaces =
+      policy_controller_->GetNamespacesForUserRequestedDownload();
 
   store_->Execute(base::BindOnce(&PersistentPageConsistencyCheckSync, store_,
                                  archive_manager_->GetPrivateArchivesDir(),

components/offline_pages/core/model/startup_maintenance_task.cc

@@ -250,15 +250,10 @@ bool StartupMaintenanceSync(OfflinePageMetadataStoreSQL* store,
   if (!db)
     return false;
 
-  std::vector<std::string> namespaces = policy_controller->GetAllNamespaces();
-  std::vector<std::string> temporary_namespaces;
-  std::vector<std::string> persistent_namespaces;
-  for (const auto& name_space : namespaces) {
-    if (!policy_controller->IsRemovedOnCacheReset(name_space))
-      persistent_namespaces.push_back(name_space);
-    else
-      temporary_namespaces.push_back(name_space);
-  }
+  std::vector<std::string> temporary_namespaces =
+      policy_controller->GetNamespacesRemovedOnCacheReset();
+  std::vector<std::string> persistent_namespaces =
+      policy_controller->GetNamespacesForUserRequestedDownload();
 
   // Clear temporary pages that are in legacy directory, which is also the
   // directory that serves as the 'private' directory.
@@ -273,6 +268,7 @@ bool StartupMaintenanceSync(OfflinePageMetadataStoreSQL* store,
                             result, SyncOperationResult::RESULT_COUNT);
 
   // Report storage usage UMA.
+  std::vector<std::string> namespaces = policy_controller->GetAllNamespaces();
   ReportStorageUsageSync(db, namespaces, archive_manager);
 
   return true;