Add a flag to control whether there is a shortcut for the app list / launcher in the Windows taskba…

chrome/browser/ui/app_list/app_list_controller.cc

Index: chrome/browser/ui/app_list/app_list_controller.cc
diff --git a/chrome/browser/ui/app_list/app_list_controller.cc b/chrome/browser/ui/app_list/app_list_controller.cc
index ce72476c29ab72bd6ee2f63d204ccb5d4220f473..1fb2d25c7e5c7563e2fd49281415f51022d4d1de 100644
--- a/chrome/browser/ui/app_list/app_list_controller.cc
+++ b/chrome/browser/ui/app_list/app_list_controller.cc
@@ -34,6 +34,9 @@ namespace app_list_controller {
 #if !defined(OS_WIN)
 // Default implementation for ports which do not have this implemented.
 void ShowAppList() {}
+
+// Default implementation for ports which do not have this implemented.
+void CheckAppListTaskbarShortcut() {}
 #endif
 
 }  // namespace app_list_controller