Register a pref to control migration status

components/content_settings/core/common/pref_names.cc

Index: components/content_settings/core/common/pref_names.cc
diff --git a/components/content_settings/core/common/pref_names.cc b/components/content_settings/core/common/pref_names.cc
index ebcf7f0608e16f80c79dc52fc8ddf3e2599c2b08..6ac2495cf3d33efa71b61b8e83ef0376c4be4323 100644
--- a/components/content_settings/core/common/pref_names.cc
+++ b/components/content_settings/core/common/pref_names.cc
@@ -18,6 +18,12 @@ const char kContentSettingsVersion[] = "profile.content_settings.pref_version";
 const char kContentSettingsWindowLastTabIndex[] =
     "content_settings_window.last_tab_index";
 
+// Integer that indicates which status currently is in of migrating domain
+// scoped settings.
+// TODO(lshang): Remove this when all migration is done. See crbug.com/621398.
+const char kContentSettingsMigrationStatus[] =
+    "profile.content_settings.migration_status";
+
 // Preferences that are exclusively used to store managed values for default
 // content settings.
 const char kManagedDefaultCookiesSetting[] =