Revert recent changes to base::Value

chrome/browser/extensions/extension_tabs_module.cc

Index: chrome/browser/extensions/extension_tabs_module.cc
diff --git a/chrome/browser/extensions/extension_tabs_module.cc b/chrome/browser/extensions/extension_tabs_module.cc
index 9a6ded91a35d14554db6563fb4a97a12b23d44ed..a949b4df1de9d75d041314d9248999ed25cfe9b4 100644
--- a/chrome/browser/extensions/extension_tabs_module.cc
+++ b/chrome/browser/extensions/extension_tabs_module.cc
@@ -417,7 +417,8 @@ bool CreateWindowFunction::RunImpl() {
         std::string url_string;
         url_value->GetAsString(&url_string);
         url_strings.push_back(url_string);
-      } else if (const ListValue* url_list = url_value->AsList()) {
+      } else if (url_value->IsType(Value::TYPE_LIST)) {
+        const ListValue* url_list = static_cast<const ListValue*>(url_value);
         for (size_t i = 0; i < url_list->GetSize(); ++i) {
           std::string url_string;
           EXTENSION_FUNCTION_VALIDATE(url_list->GetString(i, &url_string));