Makes it so each windowtreeclient can use whatever ids it wants

components/mus/ws/connection_manager.cc

Index: components/mus/ws/connection_manager.cc
diff --git a/components/mus/ws/connection_manager.cc b/components/mus/ws/connection_manager.cc
index c7a6bee3a7fb9e3e7bd1b8d2aa60ed81268495e5..0604537ea8f770b95f898ba6955b7745546cd662 100644
--- a/components/mus/ws/connection_manager.cc
+++ b/components/mus/ws/connection_manager.cc
@@ -283,27 +283,29 @@ void ConnectionManager::WindowManagerChangeCompleted(
 void ConnectionManager::WindowManagerCreatedTopLevelWindow(
     WindowTreeImpl* wm_connection,
     uint32_t window_manager_change_id,
-    Id transport_window_id) {
+    const ServerWindow* window) {
   InFlightWindowManagerChange change;
   if (!GetAndClearInFlightWindowManagerChange(window_manager_change_id,
                                               &change)) {
     return;
   }
+  if (!window) {
+    WindowManagerSentBogusMessage();
+    return;
+  }
 
-  const WindowId window_id(WindowIdFromTransportId(transport_window_id));
-  const ServerWindow* window = GetWindow(window_id);
   WindowTreeImpl* connection = GetConnection(change.connection_id);
   // The window manager should have created the window already, and it should
   // be ready for embedding.
   if (!connection->IsWaitingForNewTopLevelWindow(window_manager_change_id) ||
       !window || window->id().connection_id != wm_connection->id() ||
       !window->children().empty() || GetConnectionWithRoot(window)) {
-    WindowManagerSentBogusMessage(connection);
+    WindowManagerSentBogusMessage();
     return;
   }
 
   connection->OnWindowManagerCreatedTopLevelWindow(
-      window_manager_change_id, change.client_change_id, window_id);
+      window_manager_change_id, change.client_change_id, window);
 }
 
 void ConnectionManager::ProcessWindowBoundsChanged(