Add an accessibility description for notification

ui/arc/notification/arc_notification_content_view.cc

Index: ui/arc/notification/arc_notification_content_view.cc
diff --git a/ui/arc/notification/arc_notification_content_view.cc b/ui/arc/notification/arc_notification_content_view.cc
index 4469fc3485766281701ffddd0f05f389f56cd0ba..2d1be0e795e73f85cb67b1ab92a7fc99a6e1daa7 100644
--- a/ui/arc/notification/arc_notification_content_view.cc
+++ b/ui/arc/notification/arc_notification_content_view.cc
@@ -626,6 +626,10 @@ bool ArcNotificationContentView::HandleAccessibleAction(
 void ArcNotificationContentView::GetAccessibleNodeData(
     ui::AXNodeData* node_data) {
   node_data->role = ui::AX_ROLE_BUTTON;
+  node_data->AddStringAttribute(
+      ui::AX_ATTR_ROLE_DESCRIPTION,
+      l10n_util::GetStringUTF8(
+          IDS_MESSAGE_NOTIFICATION_SETTINGS_BUTTON_ACCESSIBLE_NAME));
   node_data->SetName(accessible_name_);
 }