prefixed namespace with "this."

Former-commit-id: 958085a5334336cbbd8bd3e7495afe02af7f70f1

common/ui/content/content-infobar.js

@@ -23,7 +23,7 @@
 
 /* global singlefile, fetch */
 
-singlefile.common.ui.content.infobar = singlefile.common.ui.content.infobar || (() => {
+this.singlefile.common.ui.content.infobar = this.singlefile.common.ui.content.infobar || (() => {
 
 	const SCRIPT_PATH = "/common/ui/content/content-infobar-web.js";