Refine UMA quality for warm-start app list cases

chrome/browser/ui/views/app_list/win/app_list_service_win.cc

Index: chrome/browser/ui/views/app_list/win/app_list_service_win.cc
diff --git a/chrome/browser/ui/views/app_list/win/app_list_service_win.cc b/chrome/browser/ui/views/app_list/win/app_list_service_win.cc
index 0525dd1f1373d99423ecd91a0808eb67421db2f4..df86e78e9523d8436dd9ea631357d6331382e1cd 100644
--- a/chrome/browser/ui/views/app_list/win/app_list_service_win.cc
+++ b/chrome/browser/ui/views/app_list/win/app_list_service_win.cc
@@ -275,7 +275,10 @@ void AppListServiceWin::OnLoadProfileForWarmup(Profile* initial_profile) {
 }
 
 void AppListServiceWin::SetAppListNextPaintCallback(void (*callback)()) {
-  next_paint_callback_ = base::Bind(callback);
+  if (shower().app_list())
+    shower().app_list()->SetNextPaintCallback(base::Bind(callback));
+  else
+    next_paint_callback_ = base::Bind(callback);
 }
 
 void AppListServiceWin::HandleFirstRun() {