Bug 1731564: Use motivated SpinEventLoopUntil inside extensions/*. r=jesup

Depends on D127225

Differential Revision: https://phabricator.services.mozilla.com/D127226

extensions/pref/autoconfig/src/nsAutoConfig.cpp

@@ -277,7 +277,8 @@ nsresult nsAutoConfig::downloadAutoConfig() {
        that mLoaded will be set to true in any case (success/failure)
     */
 
-    if (!mozilla::SpinEventLoopUntil([&]() { return mLoaded; })) {
+    if (!mozilla::SpinEventLoopUntil("nsAutoConfig::downloadAutoConfig"_ns,
+                                     [&]() { return mLoaded; })) {
       return NS_ERROR_FAILURE;
     }