[Sync] Generalize StringOrdinal to handle ordinal_in_parent field

chrome/browser/extensions/test_extension_prefs.cc

Index: chrome/browser/extensions/test_extension_prefs.cc
diff --git a/chrome/browser/extensions/test_extension_prefs.cc b/chrome/browser/extensions/test_extension_prefs.cc
index b28c5fb943ba54ec6eaee1e913e4a5be13548616..43f08bba5f41b36f1786b92d436837d0f5c939a4 100644
--- a/chrome/browser/extensions/test_extension_prefs.cc
+++ b/chrome/browser/extensions/test_extension_prefs.cc
@@ -22,6 +22,7 @@
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/common/json_pref_store.h"
 #include "content/public/browser/browser_thread.h"
+#include "sync/api/string_ordinal.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
@@ -146,7 +147,7 @@ scoped_refptr<Extension> TestExtensionPrefs::AddExtensionWithManifestAndFlags(
   EXPECT_TRUE(Extension::IdIsValid(extension->id()));
   prefs_->OnExtensionInstalled(extension, Extension::ENABLED,
                                extra_flags & Extension::FROM_WEBSTORE,
-                               StringOrdinal::CreateInitialOrdinal());
+                               syncer::StringOrdinal::CreateInitialOrdinal());
   return extension;
 }