Makes display roots be destroyed by client

services/ui/public/cpp/window_tree_client.cc

Index: services/ui/public/cpp/window_tree_client.cc
diff --git a/services/ui/public/cpp/window_tree_client.cc b/services/ui/public/cpp/window_tree_client.cc
index 0b6a5f2757601d944e5146ab6cb9c6cb4542bb02..fc9ec0c3589ea32b6d8e12d556abd7de236bc16c 100644
--- a/services/ui/public/cpp/window_tree_client.cc
+++ b/services/ui/public/cpp/window_tree_client.cc
@@ -1223,6 +1223,17 @@ void WindowTreeClient::WmNewDisplayAdded(const display::Display& display,
   WmNewDisplayAddedImpl(display, std::move(root_data), parent_drawn);
 }
 
+void WindowTreeClient::WmDisplayRemoved(int64_t display_id) {
+  DCHECK(window_manager_delegate_);
+
+  for (Window* root : roots_) {
+    if (root->display_id() == display_id) {
+      window_manager_delegate_->OnWmDisplayRemoved(root);
+      return;
+    }
+  }
+}
+
 void WindowTreeClient::WmSetBounds(uint32_t change_id,
                                        Id window_id,
                                        const gfx::Rect& transit_bounds) {