arc: Make ChromeVox read an ARC custom notification

ui/arc/notification/arc_custom_notification_item.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/arc/notification/arc_custom_notification_item.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/arc/bitmap/bitmap_type_converters.h"
@@ skipping 63 matching lines @@
   DCHECK(!data.message.is_null());
   SetNotification(base::MakeUnique<message_center::Notification>(
       message_center::NOTIFICATION_TYPE_CUSTOM, notification_id(),
       base::UTF8ToUTF16(data.title.get()),
       base::UTF8ToUTF16(data.message.get()), gfx::Image(),
       base::UTF8ToUTF16("arc"),  // display source
       GURL(),                    // empty origin url, for system component
       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();
   } else {
     snapshot_ = gfx::ImageSkia(gfx::ImageSkiaRep(
         data.snapshot_image.To<SkBitmap>(), data.snapshot_image_scale));
   }
 
   FOR_EACH_OBSERVER(Observer, observers_, OnItemUpdated());
 
@@ skipping 22 matching lines @@
 }
 
 void ArcCustomNotificationItem::DecrementWindowRefCount() {
   DCHECK_GT(window_ref_count_, 0);
   --window_ref_count_;
   if (window_ref_count_ == 0)
     manager()->CloseNotificationWindow(notification_key());
 }
 
 }  // namespace arc