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

services/ui/ws/server_window.h

Index: services/ui/ws/server_window.h
diff --git a/services/ui/ws/server_window.h b/services/ui/ws/server_window.h
index 6d66668f0114c40c7c87e8a59a56d247a7213a90..b810801c727a573030855f34e5530ce80335527b 100644
--- a/services/ui/ws/server_window.h
+++ b/services/ui/ws/server_window.h
@@ -151,6 +151,11 @@ class ServerWindow {
   void set_can_focus(bool can_focus) { can_focus_ = can_focus; }
   bool can_focus() const { return can_focus_; }
 
+  void set_can_accept_events(bool can_accept_events) {
+    can_accept_events_ = can_accept_events;
+  }
+  bool can_accept_events() const { return can_accept_events_; }
+
   // Returns true if this window is attached to a root and all ancestors are
   // visible.
   bool IsDrawn() const;
@@ -223,6 +228,7 @@ class ServerWindow {
   bool can_focus_;
   gfx::Transform transform_;
   ui::TextInputState text_input_state_;
+  bool can_accept_events_;
 
   Properties properties_;