Ensure language and country codes are not empty (#4492)

runtime/runtime_controller.h

@@ -66,8 +66,8 @@ class RuntimeController : public WindowClient, public IsolateClient {
   void DidShutdownMainIsolate() override;
 
   RuntimeDelegate* client_;
-  std::string language_code_;
-  std::string country_code_;
+  std::string language_code_ = "en";
+  std::string country_code_ = "US";
   std::string user_settings_data_ = "{}";
   bool semantics_enabled_ = false;
   std::unique_ptr<DartController> dart_controller_;

shell/common/engine.cc

@@ -118,6 +118,8 @@ Engine::Engine(PlatformView* platform_view)
           platform_view->GetVsyncWaiter(),
           this)),
       load_script_error_(tonic::kNoError),
+      language_code_("en"),
+      country_code_("US"),
       user_settings_data_("{}"),
       activity_running_(false),
       have_surface_(false),