[CRX] Remove restoretab.js logic

restoretab.js was added in mozilla#6233
with the purpose of restoring lost tabs when Chrome closes all extension
tabs when it reloads the extension. This forced reload can happen when
the user toggles the "Allow access to file URLs" option.

This logic does not work any more, and since the use of localStorage is
a blocker in migrating to MV3, this patch just drops the logic.

extensions/chromium/extension-router.js

@@ -100,28 +100,4 @@ limitations under the License.
     }
   );
   console.log("Set up extension URL router.");
-
-  Object.keys(localStorage).forEach(function (key) {
-    // The localStorage item is set upon unload by chromecom.js.
-    var parsedKey = /^unload-(\d+)-(true|false)-(.+)/.exec(key);
-    if (parsedKey) {
-      var timeStart = parseInt(parsedKey[1], 10);
-      var isHidden = parsedKey[2] === "true";
-      var url = parsedKey[3];
-      if (Date.now() - timeStart < 3000) {
-        // Is it a new item (younger than 3 seconds)? Assume that the extension
-        // just reloaded, so restore the tab (work-around for crbug.com/511670).
-        chrome.tabs.create({
-          url:
-            chrome.runtime.getURL("restoretab.html") +
-            "?" +
-            encodeURIComponent(url) +
-            "#" +
-            encodeURIComponent(localStorage.getItem(key)),
-          active: !isHidden,
-        });
-      }
-      localStorage.removeItem(key);
-    }
-  });
 })();

web/chromecom.js

@@ -249,24 +249,6 @@ function requestAccessToLocalFile(fileUrl, overlayManager, callback) {
   });
 }
 
-if (window === top) {
-  // Chrome closes all extension tabs (crbug.com/511670) when the extension
-  // reloads. To counter this, the tab URL and history state is saved to
-  // localStorage and restored by extension-router.js.
-  // Unfortunately, the window and tab index are not restored. And if it was
-  // the only tab in an incognito window, then the tab is not restored either.
-  addEventListener("unload", function () {
-    // If the runtime is still available, the unload is most likely a normal
-    // tab closure. Otherwise it is most likely an extension reload.
-    if (!isRuntimeAvailable()) {
-      localStorage.setItem(
-        "unload-" + Date.now() + "-" + document.hidden + "-" + location.href,
-        JSON.stringify(history.state)
-      );
-    }
-  });
-}
-
 let dnrRequestId;
 // This port is used for several purposes:
 // 1. When disconnected, the background page knows that the frame has unload.