Factor out test for access to localStorage (#10533)

* Factor out test for access to localStorage

This allows code that uses localStorage to test against
`window.hasLocalStorage`, in stead of handling exceptions generated when
access to localStorage is denied.

* Move check for localStorage to metabase/lib/dom

frontend/src/metabase/lib/debug.js

+import { HAS_LOCAL_STORAGE } from "metabase/lib/dom";
+
 let debug;
 if (
   typeof window === "object" &&
   ((window.location && window.location.hash === "#debug") ||
-    (window.localStorage && window.localStorage.getItem("debug")))
+    (HAS_LOCAL_STORAGE && window.localStorage.getItem("debug")))
 ) {
   debug = true;
 } else {

frontend/src/metabase/lib/dom.js

@@ -26,6 +26,18 @@ export const IFRAMED_IN_SELF = (function() {
   }
 })();
 
+// check if we have access to localStorage to avoid handling "access denied"
+// exceptions
+export const HAS_LOCAL_STORAGE = (function() {
+  try {
+    window.localStorage; // This will trigger an exception if access is denied.
+    return true;
+  } catch (e) {
+    console.warn("localStorage not available:", e);
+    return false;
+  }
+})();
+
 export function isObscured(element, offset) {
   if (!document.elementFromPoint) {
     return false;

frontend/src/metabase/lib/i18n-debug.js

 import React from "react";
 
+import { HAS_LOCAL_STORAGE } from "metabase/lib/dom";
+
 // If enabled this monkeypatches `t` and `jt` to return blacked out
 // strings/elements to assist in finding untranslated strings.
 //
@@ -52,6 +54,6 @@ export function enableTranslatedStringReplacement() {
   };
 }
 
-if (window.localStorage && window.localStorage["metabase-i18n-debug"]) {
+if (HAS_LOCAL_STORAGE && window.localStorage["metabase-i18n-debug"]) {
   enableTranslatedStringReplacement();
 }