arc: Set a name for ArcNotificationSurface

TEST=Enable debug shortcuts and press Ctrl-Shift-Alt-W
BUG=b:128650292

Change-Id: I463a74c8dadad39f1d2648c94e330b897f7fe67d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1838844Reviewed-by: Yoshiki Iguchi <yoshiki@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702770}

ash/system/message_center/arc/arc_notification_surface_impl.cc

@@ -85,6 +85,7 @@ ArcNotificationSurfaceImpl::ArcNotificationSurfaceImpl(
       new CustomWindowDelegate(surface), aura::client::WINDOW_TYPE_CONTROL);
   native_view_->set_owned_by_parent(false);
   native_view_->Init(ui::LAYER_NOT_DRAWN);
+  native_view_->SetName("ArcNotificationSurface");
   native_view_->AddChild(surface_->host_window());
   native_view_->Show();
 }