c++ / mojo changes for 'external window mode'

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 8bcba9bdff609e41ad46a6798a569cd83c50a86f..bd91a27b476e3550a1cc1902881899197cc47557 100644
--- a/services/ui/ws/window_server.cc
+++ b/services/ui/ws/window_server.cc
@@ -576,7 +576,7 @@ void WindowServer::FinishOperation() {
 void WindowServer::UpdateNativeCursorFromMouseLocation(ServerWindow* window) {
   WindowManagerDisplayRoot* display_root =
       display_manager_->GetWindowManagerDisplayRoot(window);
-  if (display_root) {
+  if (display_root && display_root->window_manager_state()) {
     EventDispatcher* event_dispatcher =
         display_root->window_manager_state()->event_dispatcher();
     event_dispatcher->UpdateCursorProviderByLastKnownLocation();
@@ -662,7 +662,7 @@ void WindowServer::OnWindowHierarchyChanged(ServerWindow* window,
 
   WindowManagerDisplayRoot* display_root =
       display_manager_->GetWindowManagerDisplayRoot(window);
-  if (display_root)
+  if (display_root && display_root->window_manager_state())
     display_root->window_manager_state()
         ->ReleaseCaptureBlockedByAnyModalWindow();