preload polymer elements in options page

chrome/browser/ui/webui/options/browser_options_handler.cc

Index: chrome/browser/ui/webui/options/browser_options_handler.cc
diff --git a/chrome/browser/ui/webui/options/browser_options_handler.cc b/chrome/browser/ui/webui/options/browser_options_handler.cc
index bc01b90c00945976a58b10734a2e6b4dbaf97f6d..de7c3bd5e9e09124330bdf4316c602e36ae40613 100644
--- a/chrome/browser/ui/webui/options/browser_options_handler.cc
+++ b/chrome/browser/ui/webui/options/browser_options_handler.cc
@@ -195,6 +195,9 @@ std::string GetSyncErrorAction(sync_ui_util::ActionType action_type) {
   }
 }
 
+#if defined(OS_CHROMEOS)
+bool g_enable_polymer_preload = true;
+#endif  // defined(OS_CHROMEOS)
 }  // namespace
 
 namespace options {
@@ -722,7 +725,8 @@ void BrowserOptionsHandler::GetLocalizedValues(base::DictionaryValue* values) {
   magnifier_list->Append(std::move(option_partial));
 
   values->Set("magnifierList", magnifier_list.release());
-#endif
+  values->SetBoolean("enablePolymerPreload", g_enable_polymer_preload);
+#endif  // defined(OS_CHROMEOS)
 
 #if defined(OS_MACOSX)
   values->SetString("macPasswordsWarning",
@@ -2351,6 +2355,13 @@ void BrowserOptionsHandler::OnPolicyUpdated(const policy::PolicyNamespace& ns,
     SetupMetricsReportingCheckbox();
 }
 
+#if defined(OS_CHROMEOS)
+// static
+void BrowserOptionsHandler::DisablePolymerPreloadForTesting() {
+  g_enable_polymer_preload = false;
+}
+#endif  // defined(OS_CHROMEOS)
+
 bool BrowserOptionsHandler::IsDeviceOwnerProfile() {
 #if defined(OS_CHROMEOS)
   return chromeos::ProfileHelper::IsOwnerProfile(Profile::FromWebUI(web_ui()));