Implement aura::WindowPortMus::CreateCompositorFrameSink()

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 2aaa85eb5d3735878584d027b3735bc6883e6e48..322cb0ce6bbd4d3024a18f7a0086dd81b07a1abd 100644
--- a/services/ui/ws/window_server.cc
+++ b/services/ui/ws/window_server.cc
@@ -882,10 +882,9 @@ void WindowServer::OnSurfaceCreated(const cc::SurfaceInfo& surface_info) {
 
   HandleTemporaryReferenceForNewSurface(surface_info.id(), window);
 
-  if (!window->parent())
-    return;
-
-  WindowTree* window_tree = GetTreeWithId(window->parent()->id().client_id);
+  // We always use the owner of the window's id (even for an embedded window),
+  // because an embedded window's id is allocated by the parent's window tree.
+  WindowTree* window_tree = GetTreeWithId(window->id().client_id);
   if (window_tree)
     window_tree->ProcessWindowSurfaceChanged(window, surface_info);
 }