Record offline histograms with suffix via Histogram::FactoryGet

components/offline_pages/offline_page_storage_manager_unittest.cc

Index: components/offline_pages/offline_page_storage_manager_unittest.cc
diff --git a/components/offline_pages/offline_page_storage_manager_unittest.cc b/components/offline_pages/offline_page_storage_manager_unittest.cc
index 9a389585bded462ff1e5b915febcc7d939c2e0bc..6198871d453f80fde3af453d9233d4eceb8fceee 100644
--- a/components/offline_pages/offline_page_storage_manager_unittest.cc
+++ b/components/offline_pages/offline_page_storage_manager_unittest.cc
@@ -13,6 +13,7 @@
 #include "base/test/simple_test_clock.h"
 #include "base/time/time.h"
 #include "components/offline_pages/archive_manager.h"
+#include "components/offline_pages/client_namespace_constants.h"
 #include "components/offline_pages/client_policy_controller.h"
 #include "components/offline_pages/offline_page_item.h"
 #include "components/offline_pages/offline_page_storage_manager.h"
@@ -27,8 +28,6 @@ using StorageStats = offline_pages::ArchiveManager::StorageStats;
 namespace offline_pages {
 
 namespace {
-const char kBookmarkNamespace[] = "bookmark";
-const char kLastNNamespace[] = "last_n";
 const GURL kTestUrl("http://example.com");
 const base::FilePath::CharType kFilePath[] = FILE_PATH_LITERAL("/data");
 const int64_t kTestFileSize = 500 * (1 << 10);