hit-test data building code should only be needed by clients via HitTestDataProviderDrawQuad. however, OOP-D is not on CrOS yet and that means ash is still using DirectLayerTreeFrameSink to submit hit-test data, which lives in viz/service. after OOP-D is launched on CrOS and everything uses AsyncLayerTreeFrameSink, we can move that code from viz/common back to viz/client