chromeos: make should_ask_children false for ws clients

We don't have any clients embedding other clients, so using false is more
correct. Additionally this ensures hit testing on renderers does not query
viz, which is a big change from the classic case.

BUG=none
TEST=none

Change-Id: If3155f8044d9c1df07165807c41bc15e3d9dbe33
Reviewed-on: https://chromium-review.googlesource.com/c/1308915Reviewed-by: Ria Jiang <riajiang@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604949}

ui/aura/mus/window_port_mus.cc

@@ -193,7 +193,7 @@ WindowPortMus::RequestLayerTreeFrameSink(
        ws::mojom::EventTargetingPolicy::TARGET_AND_DESCENDANTS);
   params.hit_test_data_provider =
       std::make_unique<viz::HitTestDataProviderDrawQuad>(
-          true /* should_ask_for_child_region */, root_accepts_events);
+          /* should_ask_for_child_regions */ false, root_accepts_events);
   params.local_surface_id_provider =
       std::make_unique<viz::DefaultLocalSurfaceIdProvider>();
   params.enable_surface_synchronization = true;