Bug 1709268 - [devtools] Remove backward compatibility code for supportsFollowWindowGlobalLifeCycleFlag r=ochameau

Differential Revision: https://phabricator.services.mozilla.com/D114221

devtools/server/actors/targets/browsing-context.js

@@ -565,9 +565,6 @@ const browsingContextTargetPrototype = {
         // support this, so we might keep this trait until all top level targets
         // can provide this flag consistently from the server.
         supportsTopLevelTargetFlag: true,
-        // @backward-compat { version 88 } Added in version 88, will not be
-        // available on targets from older servers.
-        supportsFollowWindowGlobalLifeCycleFlag: true,
       },
     };
 

devtools/shared/commands/target/target-command.js

@@ -701,15 +701,7 @@ class TargetCommand extends EventEmitter {
       dump(" target reload exception: " + e + " >>> " + e.message + " <<<\n");
       // If the target follows the window global lifecycle, the reload request
       // will fail, and we should swallow the error. Re-throw it otherwise.
-      // Reload request will fail because the target actor is going to be destroyed
-      // during the reload and so the ongoing reload request will most likely fail in some way.
-      // @backward-compat { version 88 } The trait check can be removed after
-      // version 88 hits the release channel.
-      const shouldSwallowReloadError =
-        targetFront.getTrait("supportsFollowWindowGlobalLifeCycleFlag") &&
-        targetFront.targetForm.followWindowGlobalLifeCycle;
-
-      if (!shouldSwallowReloadError) {
+      if (!targetFront.targetForm.followWindowGlobalLifeCycle) {
         throw e;
       }
     }