Fix regression when resolving ids

components/mus/ws/connection_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/ws/connection_manager.h"
 
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "components/mus/ws/client_connection.h"
 #include "components/mus/ws/connection_manager_delegate.h"
@@ skipping 521 matching lines @@
       pair.first->ScheduleSurfaceDestruction(window);
       break;
     }
   }
 }
 
 ServerWindow* ConnectionManager::FindWindowForSurface(
     const ServerWindow* ancestor,
     mojom::SurfaceType surface_type,
     const ClientWindowId& client_window_id) {
-  WindowTreeImpl* window_tree = GetConnection(ancestor->id().connection_id);
+  WindowTreeImpl* window_tree;
+  if (ancestor->id().connection_id == kInvalidConnectionId)
+    window_tree = GetWindowTreeHostByWindow(ancestor)->GetWindowTree();
+  else
+    window_tree = GetConnection(ancestor->id().connection_id);
   if (!window_tree)
     return nullptr;
   if (surface_type == mojom::SurfaceType::DEFAULT) {
     // At embed points the default surface comes from the embedded app.
     WindowTreeImpl* connection_with_root = GetConnectionWithRoot(ancestor);
     if (connection_with_root)
       window_tree = connection_with_root;
   }
   return window_tree->GetWindowByClientId(client_window_id);
 }
@@ skipping 136 matching lines @@
   if (!got_valid_frame_decorations_) {
     display_manager_observers_.AddInterfacePtr(std::move(observer));
     return;
   }
   CallOnDisplays(observer.get());
   display_manager_observers_.AddInterfacePtr(std::move(observer));
 }
 
 }  // namespace ws
 }  // namespace mus