[Media Router WebUI] Update arrow drop title text to be more descriptive.

chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc

Index: chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
diff --git a/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc b/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
index 66a54e7c02e97d447bb603fd25a67caa92e20c7f..6c374d881976a49d5868790293ed432661824730 100644
--- a/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
+++ b/chrome/browser/ui/webui/media_router/media_router_localized_strings_provider.cc
@@ -21,10 +21,12 @@ void AddMediaRouterStrings(content::WebUIDataSource* html_source) {
                                   IDS_MEDIA_ROUTER_BACK_BUTTON_TITLE);
   html_source->AddLocalizedString("closeButtonTitle",
                                   IDS_MEDIA_ROUTER_CLOSE_BUTTON_TITLE);
-  html_source->AddLocalizedString("dropDownButtonTitle",
-                                  IDS_MEDIA_ROUTER_DROP_DOWN_BUTTON_TITLE);
   html_source->AddLocalizedString("searchButtonTitle",
                                   IDS_MEDIA_ROUTER_SEARCH_BUTTON_TITLE);
+  html_source->AddLocalizedString("viewCastModeListButtonTitle",
+      IDS_MEDIA_ROUTER_VIEW_CAST_MODE_LIST_BUTTON_TITLE);
+  html_source->AddLocalizedString("viewDeviceListButtonTitle",
+      IDS_MEDIA_ROUTER_VIEW_DEVICE_LIST_BUTTON_TITLE);
 }
 
 void AddRouteDetailsStrings(content::WebUIDataSource* html_source) {