chromeos: changes how DisplayManagerObservers are notified

services/ui/ws/window_server.cc

Index: services/ui/ws/window_server.cc
diff --git a/services/ui/ws/window_server.cc b/services/ui/ws/window_server.cc
index 67b312547b4c89e727ca8c52d56a89c92c95000e..812240dfd1267bead665f2862d3d10c3597d7445 100644
--- a/services/ui/ws/window_server.cc
+++ b/services/ui/ws/window_server.cc
@@ -11,6 +11,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "services/ui/ws/display.h"
+#include "services/ui/ws/display_creation_config.h"
 #include "services/ui/ws/display_manager.h"
 #include "services/ui/ws/frame_generator.h"
 #include "services/ui/ws/gpu_host.h"
@@ -69,7 +70,8 @@ WindowServer::WindowServer(WindowServerDelegate* delegate)
       next_wm_change_id_(0),
       gpu_host_(new GpuHost(this)),
       window_manager_window_tree_factory_set_(this, &user_id_tracker_),
-      frame_sink_manager_client_binding_(this) {
+      frame_sink_manager_client_binding_(this),
+      display_creation_config_(DisplayCreationConfig::UNKNOWN) {
   user_id_tracker_.AddObserver(this);
   OnUserIdAdded(user_id_tracker_.active_id());
   gpu_host_->CreateFrameSinkManager(
@@ -94,6 +96,13 @@ WindowServer::~WindowServer() {
   display_manager_.reset();
 }
 
+void WindowServer::SetDisplayCreationConfig(DisplayCreationConfig config) {
+  DCHECK(tree_map_.empty());
+  DCHECK_EQ(DisplayCreationConfig::UNKNOWN, display_creation_config_);
+  display_creation_config_ = config;
+  display_manager_->OnDisplayCreationConfigSet();
+}
+
 ServerWindow* WindowServer::CreateServerWindow(
     const WindowId& id,
     const std::map<std::string, std::vector<uint8_t>>& properties) {
@@ -150,6 +159,9 @@ WindowTree* WindowServer::CreateTreeForWindowManager(
     mojom::WindowTreeRequest window_tree_request,
     mojom::WindowTreeClientPtr window_tree_client,
     bool automatically_create_display_roots) {
+  delegate_->OnWillCreateTreeForWindowManager(
+      automatically_create_display_roots);
+
   std::unique_ptr<WindowTree> window_tree(new WindowTree(
       this, user_id, nullptr, base::WrapUnique(new WindowManagerAccessPolicy)));
   std::unique_ptr<WindowTreeBinding> window_tree_binding =