chromeos: changes how DisplayManagerObservers are notified

services/ui/ws/window_manager_window_tree_factory.cc

Index: services/ui/ws/window_manager_window_tree_factory.cc
diff --git a/services/ui/ws/window_manager_window_tree_factory.cc b/services/ui/ws/window_manager_window_tree_factory.cc
index 89711f2de86f19de85353f30fde2af3c09f8d1d5..ab38d7b2c3dc0d98381647878051f62ce06818f7 100644
--- a/services/ui/ws/window_manager_window_tree_factory.cc
+++ b/services/ui/ws/window_manager_window_tree_factory.cc
@@ -5,6 +5,7 @@
 #include "services/ui/ws/window_manager_window_tree_factory.h"
 
 #include "base/bind.h"
+#include "services/ui/ws/display_creation_config.h"
 #include "services/ui/ws/window_manager_window_tree_factory_set.h"
 #include "services/ui/ws/window_server.h"
 #include "services/ui/ws/window_server_delegate.h"
@@ -39,9 +40,13 @@ void WindowManagerWindowTreeFactory::CreateWindowTree(
   if (binding_.is_bound())
     binding_.Close();
 
-  window_manager_window_tree_factory_set_->window_server()
-      ->delegate()
-      ->OnWillCreateTreeForWindowManager(automatically_create_display_roots);
+  // If the config is MANUAL, then all WindowManagers must connect as MANUAL.
+  if (!automatically_create_display_roots &&
+      GetWindowServer()->display_creation_config() ==
+          DisplayCreationConfig::AUTOMATIC) {
+    DVLOG(1) << "CreateWindowTree() called with manual and automatic.";
+    return;
+  }
 
   SetWindowTree(GetWindowServer()->CreateTreeForWindowManager(
       user_id_, std::move(window_tree_request), std::move(window_tree_client),