The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/tast-tests/+/136adabff3702b11ad3f1ad0d9faeb66df834f5a

commit 136adabff3702b11ad3f1ad0d9faeb66df834f5a
Author: Shuhei Takahashi <nya@chromium.org>
Date: Fri Sep 21 07:51:06 2018

uiautomator: Support all available selectors.

We basically use the same name as the original UIAutomator.

- ID is kept as an alias of ResourceID because it is very
  popular selector.
- Stringer is implemented for selector for debugging purpose.

BUG= chromium:887200 
TEST=tast run DUT arcapp.Sample

Change-Id: I535cb841e2ad6df0ac0c9006e678fbdf9e5ffc21
Reviewed-on: https://chromium-review.googlesource.com/1235367
Commit-Ready: Shuhei Takahashi <nya@chromium.org>
Tested-by: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>

[modify] https://crrev.com/136adabff3702b11ad3f1ad0d9faeb66df834f5a/src/chromiumos/tast/local/arc/ui/selector.go

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform/tast-tests/+/93c3bf1d9a146bf7892d1e5a3395a4b2050ef5a9

commit 93c3bf1d9a146bf7892d1e5a3395a4b2050ef5a9
Author: Shuhei Takahashi <nya@chromium.org>
Date: Fri Sep 21 07:51:06 2018

uiautomator: Enhance ui.Object.

Adds many methods to ui.Object, especially ones to query properties.

BUG= chromium:887200 
TEST=tast run DUT arcapp.Sample

Change-Id: I6da3abcaedb97cefa984958433ea02cb42931a01
Reviewed-on: https://chromium-review.googlesource.com/1235368
Commit-Ready: Shuhei Takahashi <nya@chromium.org>
Tested-by: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>

[modify] https://crrev.com/93c3bf1d9a146bf7892d1e5a3395a4b2050ef5a9/src/chromiumos/tast/local/arc/ui/object.go

I believe basic functionality has been added.