fixup! Bug 31286: Implementation of bridge, proxy, and firewall settings in...

fixup! Bug 31286: Implementation of bridge, proxy, and firewall settings in about:preferences#connection

Bug 42421: Hide the option to remove individual Lox bridges.

We also adjust the "Remove all bridges" callback to simply set the
"TorSettings.bridge.source" to be "Invalid" since this is more
source-independent, and TorSettings will handle clearing the bridge
strings for us.

browser/components/torpreferences/content/connectionPane.js

@@ -730,11 +730,15 @@ const gBridgeGrid = {
     const qrItem = row.menu.querySelector(
       ".tor-bridges-options-qr-one-menu-item"
     );
+    const removeItem = row.menu.querySelector(
+      ".tor-bridges-options-remove-one-menu-item"
+    );
     row.menu.addEventListener("showing", () => {
-      qrItem.hidden = !(
+      const show =
         this._bridgeSource === TorBridgeSource.UserProvided ||
-        this._bridgeSource === TorBridgeSource.BridgeDB
-      );
+        this._bridgeSource === TorBridgeSource.BridgeDB;
+      qrItem.hidden = !show;
+      removeItem.hidden = !show;
     });
 
     qrItem.addEventListener("click", () => {
@@ -752,9 +756,7 @@ const gBridgeGrid = {
         ].getService(Ci.nsIClipboardHelper);
         clipboard.copyString(row.bridgeLine);
       });
-    row.menu
-      .querySelector(".tor-bridges-options-remove-one-menu-item")
-      .addEventListener("click", () => {
+    removeItem.addEventListener("click", () => {
       const bridgeLine = row.bridgeLine;
       const strings = TorSettings.bridges.bridge_strings;
       const index = strings.indexOf(bridgeLine);
@@ -2016,7 +2018,7 @@ const gBridgeSettings = {
         setTorSettings(() => {
           // This should always have the side effect of disabling bridges as
           // well.
-          TorSettings.bridges.bridge_strings = [];
+          TorSettings.bridges.source = TorBridgeSource.Invalid;
         });
       });