[Sync] Generalize StringOrdinal to handle ordinal_in_parent field

chrome/browser/media_gallery/media_galleries_preferences_unittest.cc

Index: chrome/browser/media_gallery/media_galleries_preferences_unittest.cc
diff --git a/chrome/browser/media_gallery/media_galleries_preferences_unittest.cc b/chrome/browser/media_gallery/media_galleries_preferences_unittest.cc
index fc354e82d09db6f2c7268a968b6bb1c52149afd4..337b110d4878bc0bb70848e6f1a54279bebdfd37 100644
--- a/chrome/browser/media_gallery/media_galleries_preferences_unittest.cc
+++ b/chrome/browser/media_gallery/media_galleries_preferences_unittest.cc
@@ -21,6 +21,7 @@
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/test/test_browser_thread.h"
+#include "sync/api/string_ordinal.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace chrome {
@@ -205,7 +206,7 @@ class MediaGalleriesPreferencesTest : public testing::Test {
 
     extension_service_->extension_prefs()->OnExtensionInstalled(
         extension, extensions::Extension::ENABLED, false,
-        StringOrdinal::CreateInitialOrdinal());
+        syncer::StringOrdinal::CreateInitialOrdinal());
 
     return extension;
   }