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diff --git a/devtools/client/fronts/descriptors/descriptor-mixin.js b/devtools/client/fronts/descriptors/descriptor-mixin.js
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+++ b/devtools/client/fronts/descriptors/descriptor-mixin.js
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+/**
+ * A Descriptor represents a debuggable context. It can be a browser tab, a tab on
+ * a remote device, like a tab on Firefox for Android. But it can also be an add-on,
+ * as well as firefox parent process, or just one of its content process.
+ * It can be very similar to a Target. The key difference is the lifecycle of these two classes.
+ * The descriptor is meant to be always alive and meaningful/usable until the end of the RDP connection.
+ * Typically a Tab Descriptor will describe the tab and not the one document currently loaded in this tab,
+ * while the Target, will describe this one document and a new Target may be created on each navigation.
+ */
+function DescriptorMixin(parentClass) {
+  class Descriptor extends parentClass {
+    constructor(client, targetFront, parentFront) {
+      super(client, targetFront, parentFront);
+
+      this._client = client;
+
+      // Pass a true value in order to distinguish this event reception
+      // from any manual destroy caused by the frontend
+      this.on(
+        "descriptor-destroyed",
+        this.destroy.bind(this, { isServerDestroyEvent: true })
+      );
+    }
+
+    get client() {
+      return this._client;
+    }
+
+    async destroy({ isServerDestroyEvent } = {}) {
+      if (this.isDestroyed()) {
+        return;
+      }
+      // This workaround is mostly done for Workers, as WorkerDescriptor
+      // extends the Target class, which causes some issue down the road:
+      // In Target.destroy, we call WorkerDescriptorActor.detach *before* calling super.destroy(),
+      // and so hold on before calling Front.destroy() which would reject all pending requests, including detach().
+      // When calling detach, the server will emit "descriptor-destroyed", which will call Target.destroy again,
+      // but will still be blocked on detach resolution and won't call Front.destroy, and won't reject pending requests either.
+      //
+      // So call Front.baseFrontClassDestroyed manually from here, so that we ensure rejecting the pending detach request
+      // and unblock Target.destroy resolution.
+      //
+      // Here is the inheritance chain for WorkerDescriptor:
+      // WorkerDescriptor -> Descriptor (from descriptor-mixin.js) -> Target (from target-mixin.js) -> Front (protocol.js) -> Pool (protocol.js) -> EventEmitter
+      if (isServerDestroyEvent) {
+        this.baseFrontClassDestroy();
+      }
+
+      await super.destroy();
+    }
+  }
+  return Descriptor;
+}
+exports.DescriptorMixin = DescriptorMixin;