arc: Make ChromeVox read an ARC custom notification

ui/arc/notification/arc_custom_notification_item.cc

Index: ui/arc/notification/arc_custom_notification_item.cc
diff --git a/ui/arc/notification/arc_custom_notification_item.cc b/ui/arc/notification/arc_custom_notification_item.cc
index 79e4a9a858914504661bbfadeb8144cdeedbc406..a58ebec151c08ea04f7a87e6f024cb2e98c01ad8 100644
--- a/ui/arc/notification/arc_custom_notification_item.cc
+++ b/ui/arc/notification/arc_custom_notification_item.cc
@@ -81,6 +81,9 @@ void ArcCustomNotificationItem::UpdateWithArcNotificationData(
       notifier_id, rich_data, new ArcNotificationDelegate(this)));
 
   pinned_ = rich_data.pinned;
+  if (!data.accessible_name.is_null()) {
+    accessible_name_ = base::UTF8ToUTF16(data.accessible_name.get());

[yawano, 2016/09/06 08:07:16]

You will need to set empty string to accessible_name_ if data.accessible_name is
null. If this has been updated with new data with accessible_name==null, this
can have stale accessible name.

[yhanada, 2016/09/06 10:15:01]

Done.

+  }
 
   if (data.snapshot_image.is_null()) {
     snapshot_ = gfx::ImageSkia();