mus: Disregard windows that explicitly set can_accept_events to be false when sending events.

services/ui/ws/window_tree.cc

Index: services/ui/ws/window_tree.cc
diff --git a/services/ui/ws/window_tree.cc b/services/ui/ws/window_tree.cc
index 8a62bdd534534c4c4b111647511e306071068afe..ca962da817cb0a6694f1af823ec8d797cb4f1ca4 100644
--- a/services/ui/ws/window_tree.cc
+++ b/services/ui/ws/window_tree.cc
@@ -347,6 +347,15 @@ bool WindowTree::SetFocus(const ClientWindowId& window_id) {
   return success;
 }
 
+void WindowTree::SetCanAcceptEvents(Id transport_window_id,
+                                    bool can_accept_events) {
+  ServerWindow* window =
+      GetWindowByClientId(ClientWindowId(transport_window_id));
+  // TODO(riajiang): check |event_queue_| is empty for |window|.
+  if (window && access_policy_->CanSetAcceptEvents(window))
+    window->set_can_accept_events(can_accept_events);
+}
+
 bool WindowTree::Embed(const ClientWindowId& window_id,
                        mojom::WindowTreeClientPtr client,
                        uint32_t flags) {