Merging upstream version 126.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
author: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-05-15 03:34:50 +0000
committer: Daniel Baumann <daniel.baumann@progress-linux.org> 2024-05-15 03:34:50 +0000
commit: def92d1b8e9d373e2f6f27c366d578d97d8960c6 (patch)
tree: 2ef34b9ad8bb9a9220e05d60352558b15f513894 /devtools/server/actors
parent: Adding debian version 125.0.3-1. (diff)
download: firefox-def92d1b8e9d373e2f6f27c366d578d97d8960c6.tar.xz
firefox-def92d1b8e9d373e2f6f27c366d578d97d8960c6.zip
41 files changed, 491 insertions, 1387 deletions
diff --git a/devtools/server/actors/accessibility/audit/contrast.js b/devtools/server/actors/accessibility/audit/contrast.js
index 68e7b497f8..95510be4fc 100644
--- a/devtools/server/actors/accessibility/audit/contrast.js
+++ b/devtools/server/actors/accessibility/audit/contrast.js
@@ -42,15 +42,17 @@ loader.lazyRequireGetter(
 );
 loader.lazyRequireGetter(
   this,
-  "DevToolsWorker",
-  "resource://devtools/shared/worker/worker.js",
-  true
-);
-loader.lazyRequireGetter(
-  this,
   "InspectorActorUtils",
   "resource://devtools/server/actors/inspector/utils.js"
 );
+const lazy = {};
+ChromeUtils.defineESModuleGetters(
+  lazy,
+  {
+    DevToolsWorker: "resource://devtools/shared/worker/worker.sys.mjs",
+  },
+  { global: "contextual" }
+);
 
 const WORKER_URL = "resource://devtools/server/actors/accessibility/worker.js";
 const HIGHLIGHTED_PSEUDO_CLASS = ":-moz-devtools-highlighted";
@@ -58,7 +60,7 @@ const {
   LARGE_TEXT: { BOLD_LARGE_TEXT_MIN_PIXELS, LARGE_TEXT_MIN_PIXELS },
 } = require("resource://devtools/shared/accessibility.js");
 
-loader.lazyGetter(this, "worker", () => new DevToolsWorker(WORKER_URL));
+loader.lazyGetter(this, "worker", () => new lazy.DevToolsWorker(WORKER_URL));
 
 /**
  * Get canvas rendering context for the current target window bound by the bounds of the
diff --git a/devtools/server/actors/blackboxing.js b/devtools/server/actors/blackboxing.js
index 49dfc8180d..8163327b46 100644
--- a/devtools/server/actors/blackboxing.js
+++ b/devtools/server/actors/blackboxing.js
@@ -9,9 +9,10 @@ const {
   blackboxingSpec,
 } = require("resource://devtools/shared/specs/blackboxing.js");
 
-const {
-  SessionDataHelpers,
-} = require("resource://devtools/server/actors/watcher/SessionDataHelpers.jsm");
+const { SessionDataHelpers } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/SessionDataHelpers.sys.mjs",
+  { global: "contextual" }
+);
 const { SUPPORTED_DATA } = SessionDataHelpers;
 const { BLACKBOXING } = SUPPORTED_DATA;
 
diff --git a/devtools/server/actors/breakpoint-list.js b/devtools/server/actors/breakpoint-list.js
index 1f9d6c0bf9..a28ffc3f7a 100644
--- a/devtools/server/actors/breakpoint-list.js
+++ b/devtools/server/actors/breakpoint-list.js
@@ -9,9 +9,10 @@ const {
   breakpointListSpec,
 } = require("resource://devtools/shared/specs/breakpoint-list.js");
 
-const {
-  SessionDataHelpers,
-} = require("resource://devtools/server/actors/watcher/SessionDataHelpers.jsm");
+const { SessionDataHelpers } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/SessionDataHelpers.sys.mjs",
+  { global: "contextual" }
+);
 const { SUPPORTED_DATA } = SessionDataHelpers;
 const { BREAKPOINTS, XHR_BREAKPOINTS, EVENT_BREAKPOINTS } = SUPPORTED_DATA;
 
diff --git a/devtools/server/actors/inspector/walker.js b/devtools/server/actors/inspector/walker.js
index 50df1720b7..fbf417565c 100644
--- a/devtools/server/actors/inspector/walker.js
+++ b/devtools/server/actors/inspector/walker.js
@@ -384,7 +384,6 @@ class WalkerActor extends Actor {
       this.layoutHelpers = null;
       this._orphaned = null;
       this._retainedOrphans = null;
-      this._nodeActorsMap = null;
 
       this.targetActor.off("will-navigate", this.onFrameUnload);
       this.targetActor.off("window-ready", this.onFrameLoad);
@@ -433,6 +432,9 @@ class WalkerActor extends Actor {
         this._onEventListenerChange
       );
 
+      // Only nullify some key attributes after having removed all the listeners
+      // as they may still be used in the related listeners.
+      this._nodeActorsMap = null;
       this.onMutations = null;
 
       this.layoutActor = null;
diff --git a/devtools/server/actors/page-style.js b/devtools/server/actors/page-style.js
index 1783b58a8f..b37816c85f 100644
--- a/devtools/server/actors/page-style.js
+++ b/devtools/server/actors/page-style.js
@@ -704,6 +704,7 @@ class PageStyleActor extends Actor {
       case "::first-line":
       case "::selection":
       case "::highlight":
+      case "::target-text":
         return true;
       case "::marker":
         return this._nodeIsListItem(node);
diff --git a/devtools/server/actors/resources/index.js b/devtools/server/actors/resources/index.js
index e2857502ad..cfc941a161 100644
--- a/devtools/server/actors/resources/index.js
+++ b/devtools/server/actors/resources/index.js
@@ -390,6 +390,14 @@ exports.hasResourceTypesForTargets = hasResourceTypesForTargets;
  *        List of all type of resource to stop listening to.
  */
 function unwatchResources(rootOrWatcherOrTargetActor, resourceTypes) {
+  // If we are given a target actor, filter out the resource types supported by the target.
+  // When using sharedData to pass types between processes, we are passing them for all target types.
+  const { targetType } = rootOrWatcherOrTargetActor;
+  // Only target actors usecase will have a target type.
+  // For Root and Watcher we process the `resourceTypes` list unfiltered.
+  if (targetType) {
+    resourceTypes = getResourceTypesForTargetType(resourceTypes, targetType);
+  }
   for (const resourceType of resourceTypes) {
     // Pull all info about this resource type from `Resources` global object
     const { watchers } = getResourceTypeEntry(
@@ -415,6 +423,14 @@ exports.unwatchResources = unwatchResources;
  *        List of all type of resource to clear.
  */
 function clearResources(rootOrWatcherOrTargetActor, resourceTypes) {
+  // If we are given a target actor, filter out the resource types supported by the target.
+  // When using sharedData to pass types between processes, we are passing them for all target types.
+  const { targetType } = rootOrWatcherOrTargetActor;
+  // Only target actors usecase will have a target type.
+  // For Root and Watcher we process the `resourceTypes` list unfiltered.
+  if (targetType) {
+    resourceTypes = getResourceTypesForTargetType(resourceTypes, targetType);
+  }
   for (const resourceType of resourceTypes) {
     const { watchers } = getResourceTypeEntry(
       rootOrWatcherOrTargetActor,
diff --git a/devtools/server/actors/resources/jstracer-state.js b/devtools/server/actors/resources/jstracer-state.js
index 74491a6ced..1bb4723b55 100644
--- a/devtools/server/actors/resources/jstracer-state.js
+++ b/devtools/server/actors/resources/jstracer-state.js
@@ -8,13 +8,10 @@ const {
   TYPES: { JSTRACER_STATE },
 } = require("resource://devtools/server/actors/resources/index.js");
 
-// Bug 1827382, as this module can be used from the worker thread,
-// the following JSM may be loaded by the worker loader until
-// we have proper support for ESM from workers.
-const {
-  addTracingListener,
-  removeTracingListener,
-} = require("resource://devtools/server/tracer/tracer.jsm");
+const { JSTracer } = ChromeUtils.importESModule(
+  "resource://devtools/server/tracer/tracer.sys.mjs",
+  { global: "contextual" }
+);
 
 const { LOG_METHODS } = require("resource://devtools/server/actors/tracer.js");
 const Targets = require("resource://devtools/server/actors/targets/index.js");
@@ -42,7 +39,7 @@ class TracingStateWatcher {
     this.tracingListener = {
       onTracingToggled: this.onTracingToggled.bind(this),
     };
-    addTracingListener(this.tracingListener);
+    JSTracer.addTracingListener(this.tracingListener);
   }
 
   /**
@@ -52,7 +49,7 @@ class TracingStateWatcher {
     if (!this.tracingListener) {
       return;
     }
-    removeTracingListener(this.tracingListener);
+    JSTracer.removeTracingListener(this.tracingListener);
   }
 
   /**
diff --git a/devtools/server/actors/resources/network-events.js b/devtools/server/actors/resources/network-events.js
index 909c16e052..9401d835ff 100644
--- a/devtools/server/actors/resources/network-events.js
+++ b/devtools/server/actors/resources/network-events.js
@@ -9,9 +9,9 @@ const { isWindowGlobalPartOfContext } = ChromeUtils.importESModule(
   "resource://devtools/server/actors/watcher/browsing-context-helpers.sys.mjs",
   { global: "contextual" }
 );
-const { WatcherRegistry } = ChromeUtils.importESModule(
-  "resource://devtools/server/actors/watcher/WatcherRegistry.sys.mjs",
-  // WatcherRegistry needs to be a true singleton and loads ActorManagerParent
+const { ParentProcessWatcherRegistry } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/ParentProcessWatcherRegistry.sys.mjs",
+  // ParentProcessWatcherRegistry needs to be a true singleton and loads ActorManagerParent
   // which also has to be a true singleton.
   { global: "shared" }
 );
@@ -253,7 +253,7 @@ class NetworkEventWatcher {
     // (i.e. the process where this Watcher runs)
     const isParentProcessOnlyBrowserToolbox =
       this.watcherActor.sessionContext.type == "all" &&
-      !WatcherRegistry.isWatchingTargets(
+      !ParentProcessWatcherRegistry.isWatchingTargets(
         this.watcherActor,
         Targets.TYPES.FRAME
       );
diff --git a/devtools/server/actors/resources/sources.js b/devtools/server/actors/resources/sources.js
index c4f0601106..63a5987e0e 100644
--- a/devtools/server/actors/resources/sources.js
+++ b/devtools/server/actors/resources/sources.js
@@ -44,6 +44,8 @@ class SourceWatcher {
     this.sourcesManager = targetActor.sourcesManager;
     this.onAvailable = onAvailable;
 
+    threadActor.attach({});
+
     // Disable `ThreadActor.newSource` RDP event in order to avoid unnecessary traffic
     threadActor.disableNewSourceEvents();
 
diff --git a/devtools/server/actors/resources/utils/parent-process-storage.js b/devtools/server/actors/resources/utils/parent-process-storage.js
index 760e6e4d38..1d3a3dd341 100644
--- a/devtools/server/actors/resources/utils/parent-process-storage.js
+++ b/devtools/server/actors/resources/utils/parent-process-storage.js
@@ -79,11 +79,12 @@ class ParentProcessStorage {
         watcherActor.sessionContext;
       await this._spawnActor(addonBrowsingContextID, addonInnerWindowId);
     } else if (watcherActor.sessionContext.type == "all") {
-      const parentProcessTargetActor =
-        this.watcherActor.getTargetActorInParentProcess();
-      const { browsingContextID, innerWindowId } =
-        parentProcessTargetActor.form();
-      await this._spawnActor(browsingContextID, innerWindowId);
+      // Note that there should be only one such target in the browser toolbox.
+      // The Parent Process Target Actor.
+      for (const targetActor of this.watcherActor.getTargetActorsInParentProcess()) {
+        const { browsingContextID, innerWindowId } = targetActor.form();
+        await this._spawnActor(browsingContextID, innerWindowId);
+      }
     } else {
       throw new Error(
         "Unsupported session context type=" + watcherActor.sessionContext.type
diff --git a/devtools/server/actors/style-rule.js b/devtools/server/actors/style-rule.js
index e9f39fa3d0..9ddd6a380c 100644
--- a/devtools/server/actors/style-rule.js
+++ b/devtools/server/actors/style-rule.js
@@ -724,7 +724,7 @@ class StyleRuleActor extends Actor {
       const cssText = await this.pageStyle.styleSheetsManager.getText(
         resourceId
       );
-      const { text } = getRuleText(cssText, this.line, this.column);
+      const text = getRuleText(cssText, this.line, this.column);
       // Cache the result on the rule actor to avoid parsing again next time
       this._failedToGetRuleText = false;
       this.authoredText = text;
@@ -823,19 +823,32 @@ class StyleRuleActor extends Actor {
         this.pageStyle.styleSheetsManager.getStyleSheetResourceId(
           this._parentSheet
         );
-      let cssText = await this.pageStyle.styleSheetsManager.getText(resourceId);
 
-      const { offset, text } = getRuleText(cssText, this.line, this.column);
-      cssText =
-        cssText.substring(0, offset) +
-        newText +
-        cssText.substring(offset + text.length);
-
-      await this.pageStyle.styleSheetsManager.setStyleSheetText(
-        resourceId,
-        cssText,
-        { kind: UPDATE_PRESERVING_RULES }
+      const sheetText = await this.pageStyle.styleSheetsManager.getText(
+        resourceId
+      );
+      const cssText = InspectorUtils.replaceBlockRuleBodyTextInStylesheet(
+        sheetText,
+        this.line,
+        this.column,
+        newText
       );
+
+      if (typeof cssText !== "string") {
+        throw new Error(
+          "Error in InspectorUtils.replaceBlockRuleBodyTextInStylesheet"
+        );
+      }
+
+      // setStyleSheetText will parse the stylesheet which can be costly, so only do it
+      // if the text has actually changed.
+      if (sheetText !== newText) {
+        await this.pageStyle.styleSheetsManager.setStyleSheetText(
+          resourceId,
+          cssText,
+          { kind: UPDATE_PRESERVING_RULES }
+        );
+      }
     }
 
     this.authoredText = newText;
diff --git a/devtools/server/actors/target-configuration.js b/devtools/server/actors/target-configuration.js
index b6db235143..e739c1cc3d 100644
--- a/devtools/server/actors/target-configuration.js
+++ b/devtools/server/actors/target-configuration.js
@@ -9,9 +9,10 @@ const {
   targetConfigurationSpec,
 } = require("resource://devtools/shared/specs/target-configuration.js");
 
-const {
-  SessionDataHelpers,
-} = require("resource://devtools/server/actors/watcher/SessionDataHelpers.jsm");
+const { SessionDataHelpers } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/SessionDataHelpers.sys.mjs",
+  { global: "contextual" }
+);
 const { isBrowsingContextPartOfContext } = ChromeUtils.importESModule(
   "resource://devtools/server/actors/watcher/browsing-context-helpers.sys.mjs",
   { global: "contextual" }
@@ -486,7 +487,10 @@ class TargetConfigurationActor extends Actor {
       "bf-cache-navigation-pageshow",
       this._onBfCacheNavigation
     );
-    this._restoreParentProcessConfiguration();
+    // Avoid trying to restore if the related context is already being destroyed
+    if (this._browsingContext && !this._browsingContext.isDiscarded) {
+      this._restoreParentProcessConfiguration();
+    }
     super.destroy();
   }
 }
diff --git a/devtools/server/actors/targets/base-target-actor.js b/devtools/server/actors/targets/base-target-actor.js
index f3fc2a89e7..646874c4f1 100644
--- a/devtools/server/actors/targets/base-target-actor.js
+++ b/devtools/server/actors/targets/base-target-actor.js
@@ -203,6 +203,18 @@ class BaseTargetActor extends Actor {
       ) {
         return;
       }
+      // In the browser toolbox, when debugging the parent process, we should only toggle the tracer in the Parent Process Target Actor.
+      // We have to ignore any frame target which may run in the parent process.
+      // For example DevTools documents or a tab running in the parent process.
+      // (PROCESS_TYPE_DEFAULT refers to the parent process)
+      if (
+        this.sessionContext.type == "all" &&
+        this.targetType === Targets.TYPES.FRAME &&
+        this.typeName != "parentProcessTarget" &&
+        Services.appinfo.processType == Services.appinfo.PROCESS_TYPE_DEFAULT
+      ) {
+        return;
+      }
       const tracerActor = this.getTargetScopedActor("tracer");
       tracerActor.startTracing(options.tracerOptions);
     } else if (this.hasTargetScopedActor("tracer")) {
diff --git a/devtools/server/actors/targets/session-data-processors/breakpoints.js b/devtools/server/actors/targets/session-data-processors/breakpoints.js
index 67c270654d..8ecd80ad64 100644
--- a/devtools/server/actors/targets/session-data-processors/breakpoints.js
+++ b/devtools/server/actors/targets/session-data-processors/breakpoints.js
@@ -32,11 +32,9 @@ module.exports = {
       threadActor.removeAllBreakpoints();
     }
     const isTargetCreation = threadActor.state == THREAD_STATES.DETACHED;
-    if (isTargetCreation && !targetActor.targetType.endsWith("worker")) {
+    if (isTargetCreation) {
       // If addOrSetSessionDataEntry is called during target creation, attach the
       // thread actor automatically and pass the initial breakpoints.
-      // However, do not attach the thread actor for Workers. They use a codepath
-      // which releases the worker on `attach`. For them, the client will call `attach`. (bug 1691986)
       await threadActor.attach({ breakpoints: entries });
     } else {
       // If addOrSetSessionDataEntry is called for an existing target, set the new
diff --git a/devtools/server/actors/targets/session-data-processors/event-breakpoints.js b/devtools/server/actors/targets/session-data-processors/event-breakpoints.js
index 4eb9e4f3a8..1b2dbd847e 100644
--- a/devtools/server/actors/targets/session-data-processors/event-breakpoints.js
+++ b/devtools/server/actors/targets/session-data-processors/event-breakpoints.js
@@ -16,11 +16,8 @@ module.exports = {
     updateType
   ) {
     const { threadActor } = targetActor;
-    // Same as comments for XHR breakpoints. See lines 117-118
-    if (
-      threadActor.state == THREAD_STATES.DETACHED &&
-      !targetActor.targetType.endsWith("worker")
-    ) {
+    // The thread actor has to be initialized in order to have functional breakpoints
+    if (threadActor.state == THREAD_STATES.DETACHED) {
       threadActor.attach();
     }
     if (updateType == "set") {
diff --git a/devtools/server/actors/targets/session-data-processors/index.js b/devtools/server/actors/targets/session-data-processors/index.js
index 19b7d69302..72bc769dd1 100644
--- a/devtools/server/actors/targets/session-data-processors/index.js
+++ b/devtools/server/actors/targets/session-data-processors/index.js
@@ -4,9 +4,10 @@
 
 "use strict";
 
-const {
-  SessionDataHelpers,
-} = require("resource://devtools/server/actors/watcher/SessionDataHelpers.jsm");
+const { SessionDataHelpers } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/SessionDataHelpers.sys.mjs",
+  { global: "contextual" }
+);
 const { SUPPORTED_DATA } = SessionDataHelpers;
 
 const SessionDataProcessors = {};
diff --git a/devtools/server/actors/targets/session-data-processors/thread-configuration.js b/devtools/server/actors/targets/session-data-processors/thread-configuration.js
index ad5c0fe024..381a62f640 100644
--- a/devtools/server/actors/targets/session-data-processors/thread-configuration.js
+++ b/devtools/server/actors/targets/session-data-processors/thread-configuration.js
@@ -28,12 +28,9 @@ module.exports = {
       threadOptions[key] = value;
     }
 
-    if (
-      !targetActor.targetType.endsWith("worker") &&
-      targetActor.threadActor.state == THREAD_STATES.DETACHED
-    ) {
+    if (targetActor.threadActor.state == THREAD_STATES.DETACHED) {
       await targetActor.threadActor.attach(threadOptions);
-    } else {
+    } else if (!targetActor.threadActor.isDestroyed()) {
       // Regarding `updateType`, `entries` is always a partial set of configurations.
       // We will acknowledge the passed attribute, but if we had set some other attributes
       // before this call, they will stay as-is.
diff --git a/devtools/server/actors/targets/session-data-processors/xhr-breakpoints.js b/devtools/server/actors/targets/session-data-processors/xhr-breakpoints.js
index 3bbcf54aaf..81ecb72fb2 100644
--- a/devtools/server/actors/targets/session-data-processors/xhr-breakpoints.js
+++ b/devtools/server/actors/targets/session-data-processors/xhr-breakpoints.js
@@ -22,10 +22,7 @@ module.exports = {
 
     // The thread actor has to be initialized in order to correctly
     // retrieve the stack trace when hitting an XHR
-    if (
-      threadActor.state == THREAD_STATES.DETACHED &&
-      !targetActor.targetType.endsWith("worker")
-    ) {
+    if (threadActor.state == THREAD_STATES.DETACHED) {
       await threadActor.attach();
     }
 
diff --git a/devtools/server/actors/targets/target-actor-registry.sys.mjs b/devtools/server/actors/targets/target-actor-registry.sys.mjs
index 25c1ac1234..bc7adffec2 100644
--- a/devtools/server/actors/targets/target-actor-registry.sys.mjs
+++ b/devtools/server/actors/targets/target-actor-registry.sys.mjs
@@ -9,7 +9,8 @@
 // are still using message manager in order to avoid being destroyed on navigation.
 // And because of this, these actors aren't using JS Window Actor.
 const windowGlobalTargetActors = new Set();
-let xpcShellTargetActor = null;
+
+const xpcShellTargetActors = new Set();
 
 export var TargetActorRegistry = {
   registerTargetActor(targetActor) {
@@ -21,15 +22,15 @@ export var TargetActorRegistry = {
   },
 
   registerXpcShellTargetActor(targetActor) {
-    xpcShellTargetActor = targetActor;
+    xpcShellTargetActors.add(targetActor);
   },
 
-  unregisterXpcShellTargetActor() {
-    xpcShellTargetActor = null;
+  unregisterXpcShellTargetActor(targetActor) {
+    xpcShellTargetActors.delete(targetActor);
   },
 
-  get xpcShellTargetActor() {
-    return xpcShellTargetActor;
+  get xpcShellTargetActors() {
+    return xpcShellTargetActors;
   },
 
   /**
diff --git a/devtools/server/actors/targets/webextension.js b/devtools/server/actors/targets/webextension.js
index c717b53011..47127dc65c 100644
--- a/devtools/server/actors/targets/webextension.js
+++ b/devtools/server/actors/targets/webextension.js
@@ -162,6 +162,12 @@ class WebExtensionTargetActor extends ParentProcessTargetActor {
     // URL shown in the window tittle when the addon debugger is opened).
     const extensionWindow = this._searchForExtensionWindow();
     this.setDocShell(extensionWindow.docShell);
+
+    // `setDocShell` will force the instantiation of the thread actor.
+    // We now have to initialize it in order to listen for new global
+    // which allows to properly detect addon reload via _shouldAddNewGlobalAsDebuggee
+    // which may call _onNewExtensionWindow.
+    this.threadActor.attach({});
   }
 
   // Override the ParentProcessTargetActor's override in order to only iterate
diff --git a/devtools/server/actors/targets/window-global.js b/devtools/server/actors/targets/window-global.js
index 6719f0518d..f8f5e5f3c6 100644
--- a/devtools/server/actors/targets/window-global.js
+++ b/devtools/server/actors/targets/window-global.js
@@ -381,6 +381,15 @@ class WindowGlobalTargetActor extends BaseTargetActor {
     // (This is also probably meant to disappear once EFT is the only supported codepath)
     this._docShellsObserved = false;
     DevToolsUtils.executeSoon(() => this._watchDocshells());
+
+    // The `watchedByDevTools` enables gecko behavior tied to this flag, such as:
+    //  - reporting the contents of HTML loaded in the docshells,
+    //  - or capturing stacks for the network monitor.
+    //
+    // This flag can only be set on top level BrowsingContexts.
+    if (!this.browsingContext.parent) {
+      this.browsingContext.watchedByDevTools = true;
+    }
   }
 
   get docShell() {
@@ -480,6 +489,10 @@ class WindowGlobalTargetActor extends BaseTargetActor {
     return this.browsingContext?.id;
   }
 
+  get innerWindowId() {
+    return this.window?.windowGlobalChild.innerWindowId;
+  }
+
   get browserId() {
     return this.browsingContext?.browserId;
   }
@@ -687,6 +700,11 @@ class WindowGlobalTargetActor extends BaseTargetActor {
       response.outerWindowID = this.outerWindowID;
     }
 
+    // If the actor is already being destroyed, avoid re-registering the target scoped actors
+    if (this.destroying) {
+      return response;
+    }
+
     const actors = this._createExtraActors();
     Object.assign(response, actors);
 
@@ -731,6 +749,17 @@ class WindowGlobalTargetActor extends BaseTargetActor {
       this._touchSimulator = null;
     }
 
+    // The watchedByDevTools flag is only set on top level BrowsingContext
+    // (as it then cascades to all its children),
+    // and when destroying the target, we should tell the platform we no longer
+    // observe this BrowsingContext and set this attribute to false.
+    if (
+      this.browsingContext?.watchedByDevTools &&
+      !this.browsingContext.parent
+    ) {
+      this.browsingContext.watchedByDevTools = false;
+    }
+
     // Check for `docShell` availability, as it can be already gone during
     // Firefox shutdown.
     if (this.docShell) {
@@ -1314,10 +1343,6 @@ class WindowGlobalTargetActor extends BaseTargetActor {
     if (typeof options.touchEventsOverride !== "undefined") {
       const enableTouchSimulator = options.touchEventsOverride === "enabled";
 
-      this.docShell.metaViewportOverride = enableTouchSimulator
-        ? Ci.nsIDocShell.META_VIEWPORT_OVERRIDE_ENABLED
-        : Ci.nsIDocShell.META_VIEWPORT_OVERRIDE_NONE;
-
       // We want to reload the document if it's an "existing" top level target on which
       // the touch simulator will be toggled and the user has turned the
       // "reload on touch simulation" setting on.
@@ -1384,7 +1409,14 @@ class WindowGlobalTargetActor extends BaseTargetActor {
    */
   _restoreTargetConfiguration() {
     if (this._restoreFocus && this.browsingContext?.isActive) {
-      this.window.focus();
+      try {
+        this.window.focus();
+      } catch (e) {
+        // When closing devtools while navigating, focus() may throw NS_ERROR_XPC_SECURITY_MANAGER_VETO
+        if (e.result != Cr.NS_ERROR_XPC_SECURITY_MANAGER_VETO) {
+          throw e;
+        }
+      }
     }
   }
 
@@ -1688,17 +1720,6 @@ class DebuggerProgressListener {
       this._knownWindowIDs.set(getWindowID(win), win);
     }
 
-    // The `watchedByDevTools` enables gecko behavior tied to this flag, such as:
-    //  - reporting the contents of HTML loaded in the docshells,
-    //  - or capturing stacks for the network monitor.
-    //
-    // This flag is also set in frame-helper but in the case of the browser toolbox, we
-    // don't have the watcher enabled by default yet, and as a result we need to set it
-    // here for the parent process window global.
-    // This should be removed as part of Bug 1709529.
-    if (this._targetActor.typeName === "parentProcessTarget") {
-      docShell.browsingContext.watchedByDevTools = true;
-    }
     // Immediately enable CSS error reports on new top level docshells, if this was already enabled.
     // This is specific to MBT and WebExtension targets (so the isRootActor check).
     if (
@@ -1741,12 +1762,6 @@ class DebuggerProgressListener {
     for (const win of windows) {
       this._knownWindowIDs.delete(getWindowID(win));
     }
-
-    // We only reset it for parent process target actor as the flag should be set in parent
-    // process, and thus is set elsewhere for other type of BrowsingContextActor.
-    if (this._targetActor.typeName === "parentProcessTarget") {
-      docShell.browsingContext.watchedByDevTools = false;
-    }
   }
 
   _getWindowsInDocShell(docShell) {
diff --git a/devtools/server/actors/targets/worker.js b/devtools/server/actors/targets/worker.js
index 20b60cfa24..7604b5be6e 100644
--- a/devtools/server/actors/targets/worker.js
+++ b/devtools/server/actors/targets/worker.js
@@ -126,12 +126,6 @@ class WorkerTargetActor extends BaseTargetActor {
     return this._sourcesManager;
   }
 
-  // This is called from the ThreadActor#onAttach method
-  onThreadAttached() {
-    // This isn't an RDP event and is only listened to from startup/worker.js.
-    this.emit("worker-thread-attached");
-  }
-
   destroy() {
     super.destroy();
 
diff --git a/devtools/server/actors/thread-configuration.js b/devtools/server/actors/thread-configuration.js
index f0c697bb51..d3b7e229bf 100644
--- a/devtools/server/actors/thread-configuration.js
+++ b/devtools/server/actors/thread-configuration.js
@@ -9,9 +9,10 @@ const {
   threadConfigurationSpec,
 } = require("resource://devtools/shared/specs/thread-configuration.js");
 
-const {
-  SessionDataHelpers,
-} = require("resource://devtools/server/actors/watcher/SessionDataHelpers.jsm");
+const { SessionDataHelpers } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/SessionDataHelpers.sys.mjs",
+  { global: "contextual" }
+);
 const {
   SUPPORTED_DATA: { THREAD_CONFIGURATION },
 } = SessionDataHelpers;
diff --git a/devtools/server/actors/thread.js b/devtools/server/actors/thread.js
index 07dcc27a6a..0042e76a2a 100644
--- a/devtools/server/actors/thread.js
+++ b/devtools/server/actors/thread.js
@@ -418,12 +418,6 @@ class ThreadActor extends Actor {
     this.alreadyAttached = true;
     this.dbg.enable();
 
-    // Notify the target actor that we've finished attaching. If this is a worker
-    // thread which was paused until attaching, this will allow content to
-    // begin executing.
-    if (this.targetActor.onThreadAttached) {
-      this.targetActor.onThreadAttached();
-    }
     if (Services.obs) {
       // Set a wrappedJSObject property so |this| can be sent via the observer service
       // for the xpcshell harness.
@@ -535,6 +529,13 @@ class ThreadActor extends Actor {
   }
 
   async setBreakpoint(location, options) {
+    // Automatically initialize the thread actor if it wasn't yet done.
+    // Note that ideally, it should rather be done via reconfigure/thread configuration.
+    if (this._state === STATES.DETACHED) {
+      this.attach({});
+      this.addAllSources();
+    }
+
     let actor = this.breakpointActorMap.get(location);
     // Avoid resetting the exact same breakpoint twice
     if (actor && JSON.stringify(actor.options) == JSON.stringify(options)) {
@@ -597,7 +598,9 @@ class ThreadActor extends Actor {
   }
 
   getAvailableEventBreakpoints() {
-    return getAvailableEventBreakpoints(this.targetActor.window);
+    return getAvailableEventBreakpoints(
+      this.targetActor.window || this.targetActor.workerGlobal
+    );
   }
   getActiveEventBreakpoints() {
     return Array.from(this._activeEventBreakpoints);
diff --git a/devtools/server/actors/tracer.js b/devtools/server/actors/tracer.js
index bf759cee5f..d98749ceb1 100644
--- a/devtools/server/actors/tracer.js
+++ b/devtools/server/actors/tracer.js
@@ -4,16 +4,14 @@
 
 "use strict";
 
-// Bug 1827382, as this module can be used from the worker thread,
-// the following JSM may be loaded by the worker loader until
-// we have proper support for ESM from workers.
-const {
-  startTracing,
-  stopTracing,
-  addTracingListener,
-  removeTracingListener,
-  NEXT_INTERACTION_MESSAGE,
-} = require("resource://devtools/server/tracer/tracer.jsm");
+const lazy = {};
+ChromeUtils.defineESModuleGetters(
+  lazy,
+  {
+    JSTracer: "resource://devtools/server/tracer/tracer.sys.mjs",
+  },
+  { global: "contextual" }
+);
 
 const { Actor } = require("resource://devtools/shared/protocol.js");
 const { tracerSpec } = require("resource://devtools/shared/specs/tracer.js");
@@ -136,10 +134,10 @@ class TracerActor extends Actor {
       onTracingPending: this.onTracingPending.bind(this),
       onTracingDOMMutation: this.onTracingDOMMutation.bind(this),
     };
-    addTracingListener(this.tracingListener);
+    lazy.JSTracer.addTracingListener(this.tracingListener);
     this.traceValues = !!options.traceValues;
     try {
-      startTracing({
+      lazy.JSTracer.startTracing({
         global: this.targetActor.window || this.targetActor.workerGlobal,
         prefix: options.prefix || "",
         // Enable receiving the `currentDOMEvent` being passed to `onTracingFrame`
@@ -170,10 +168,10 @@ class TracerActor extends Actor {
       return;
     }
     // Remove before stopping to prevent receiving the stop notification
-    removeTracingListener(this.tracingListener);
+    lazy.JSTracer.removeTracingListener(this.tracingListener);
     this.tracingListener = null;
 
-    stopTracing();
+    lazy.JSTracer.stopTracing();
     this.logMethod = null;
   }
 
@@ -230,7 +228,7 @@ class TracerActor extends Actor {
       if (consoleMessageWatcher) {
         consoleMessageWatcher.emitMessages([
           {
-            arguments: [NEXT_INTERACTION_MESSAGE],
+            arguments: [lazy.JSTracer.NEXT_INTERACTION_MESSAGE],
             styles: [],
             level: "jstracer",
             chromeContext: false,
@@ -510,7 +508,7 @@ class TracerActor extends Actor {
    *        A string to be displayed as a prefix of any logged frame.
    * @param {String} options.why
    *        A string to explain why the function stopped.
-   *        See tracer.jsm's FRAME_EXIT_REASONS.
+   *        See tracer.sys.mjs's FRAME_EXIT_REASONS.
    * @param {Debugger.Object|primitive} options.rv
    *        The returned value. It can be the returned value, or the thrown exception.
    *        It is either a primitive object, otherwise it is a Debugger.Object for any other JS Object type.
diff --git a/devtools/server/actors/utils/event-breakpoints.js b/devtools/server/actors/utils/event-breakpoints.js
index a7752b8201..8fbefec804 100644
--- a/devtools/server/actors/utils/event-breakpoints.js
+++ b/devtools/server/actors/utils/event-breakpoints.js
@@ -131,7 +131,8 @@ const AVAILABLE_BREAKPOINTS = [
     items: [
       // The condition should be removed when "dom.element.popover.enabled" is removed
       generalEvent("control", "beforetoggle", () =>
-        Services.prefs.getBoolPref("dom.element.popover.enabled")
+        // Services.prefs isn't available on worker targets
+        Services.prefs?.getBoolPref("dom.element.popover.enabled")
       ),
       generalEvent("control", "blur"),
       generalEvent("control", "change"),
@@ -139,7 +140,11 @@ const AVAILABLE_BREAKPOINTS = [
       generalEvent("control", "focusin"),
       generalEvent("control", "focusout"),
       // The condition should be removed when "dom.element.invokers.enabled" is removed
-      generalEvent("control", "invoke", win => "InvokeEvent" in win),
+      generalEvent(
+        "control",
+        "invoke",
+        global => global && "InvokeEvent" in global
+      ),
       generalEvent("control", "reset"),
       generalEvent("control", "resize"),
       generalEvent("control", "scroll"),
@@ -483,17 +488,17 @@ exports.getAvailableEventBreakpoints = getAvailableEventBreakpoints;
 /**
  * Get all available event breakpoints
  *
- * @param {Window} window
+ * @param {Window|WorkerGlobalScope} global
  * @returns {Array<Object>} An array containing object with 2 properties, an id and a name,
  *          representing the event.
  */
-function getAvailableEventBreakpoints(window) {
+function getAvailableEventBreakpoints(global) {
   const available = [];
   for (const { name, items } of AVAILABLE_BREAKPOINTS) {
     available.push({
       name,
       events: items
-        .filter(item => !item.condition || item.condition(window))
+        .filter(item => !item.condition || item.condition(global))
         .map(item => ({
           id: item.id,
           name: item.name,
diff --git a/devtools/server/actors/utils/style-utils.js b/devtools/server/actors/utils/style-utils.js
index 5f2e912002..1d52448fb6 100644
--- a/devtools/server/actors/utils/style-utils.js
+++ b/devtools/server/actors/utils/style-utils.js
@@ -4,8 +4,6 @@
 
 "use strict";
 
-const { getCSSLexer } = require("resource://devtools/shared/css/lexer.js");
-
 const XHTML_NS = "http://www.w3.org/1999/xhtml";
 const FONT_PREVIEW_TEXT = "Abc";
 const FONT_PREVIEW_FONT_SIZE = 40;
@@ -120,66 +118,12 @@ function getRuleText(initialText, line, column) {
     throw new Error("Location information is missing");
   }
 
-  const { offset: textOffset, text } = getTextAtLineColumn(
-    initialText,
-    line,
-    column
-  );
-  const lexer = getCSSLexer(text);
-
-  // Search forward for the opening brace.
-  while (true) {
-    const token = lexer.nextToken();
-    if (!token) {
-      throw new Error("couldn't find start of the rule");
-    }
-    if (token.tokenType === "symbol" && token.text === "{") {
-      break;
-    }
-  }
-
-  // Now collect text until we see the matching close brace.
-  let braceDepth = 1;
-  let startOffset, endOffset;
-  while (true) {
-    const token = lexer.nextToken();
-    if (!token) {
-      break;
-    }
-    if (startOffset === undefined) {
-      startOffset = token.startOffset;
-    }
-    if (token.tokenType === "symbol") {
-      if (token.text === "{") {
-        ++braceDepth;
-      } else if (token.text === "}") {
-        --braceDepth;
-        if (braceDepth == 0) {
-          break;
-        }
-      }
-    }
-    endOffset = token.endOffset;
-  }
-
-  // If the rule was of the form "selector {" with no closing brace
-  // and no properties, just return an empty string.
-  if (startOffset === undefined) {
-    return { offset: 0, text: "" };
-  }
-  // If the input didn't have any tokens between the braces (e.g.,
-  // "div {}"), then the endOffset won't have been set yet; so account
-  // for that here.
-  if (endOffset === undefined) {
-    endOffset = startOffset;
+  const { text } = getTextAtLineColumn(initialText, line, column);
+  const res = InspectorUtils.getRuleBodyText(text);
+  if (res === null || typeof res === "undefined") {
+    throw new Error("Couldn't find rule");
   }
-
-  // Note that this approach will preserve comments, despite the fact
-  // that cssTokenizer skips them.
-  return {
-    offset: textOffset + startOffset,
-    text: text.substring(startOffset, endOffset),
-  };
+  return res;
 }
 
 exports.getRuleText = getRuleText;
diff --git a/devtools/server/actors/utils/stylesheets-manager.js b/devtools/server/actors/utils/stylesheets-manager.js
index a9c0705e8d..1c065afd4e 100644
--- a/devtools/server/actors/utils/stylesheets-manager.js
+++ b/devtools/server/actors/utils/stylesheets-manager.js
@@ -446,10 +446,12 @@ class StyleSheetsManager extends EventEmitter {
     InspectorUtils.parseStyleSheet(styleSheet, text);
     modifiedStyleSheets.set(styleSheet, text);
 
-    const { atRules, ruleCount } =
-      this.getStyleSheetRuleCountAndAtRules(styleSheet);
-
+    // getStyleSheetRuleCountAndAtRules can be costly, so only call it when needed,
+    // i.e. when the whole stylesheet is modified, not when a rule body is.
+    let atRules, ruleCount;
     if (kind !== UPDATE_PRESERVING_RULES) {
+      ({ atRules, ruleCount } =
+        this.getStyleSheetRuleCountAndAtRules(styleSheet));
       this.#notifyPropertyChanged(resourceId, "ruleCount", ruleCount);
     }
 
@@ -465,13 +467,15 @@ class StyleSheetsManager extends EventEmitter {
       });
     }
 
-    this.#onStyleSheetUpdated({
-      resourceId,
-      updateKind: "at-rules-changed",
-      updates: {
-        resourceUpdates: { atRules },
-      },
-    });
+    if (kind !== UPDATE_PRESERVING_RULES) {
+      this.#onStyleSheetUpdated({
+        resourceId,
+        updateKind: "at-rules-changed",
+        updates: {
+          resourceUpdates: { atRules },
+        },
+      });
+    }
   }
 
   /**
@@ -705,6 +709,13 @@ class StyleSheetsManager extends EventEmitter {
           line: InspectorUtils.getRelativeRuleLine(rule),
           column: InspectorUtils.getRuleColumn(rule),
         });
+      } else if (className === "CSSPropertyRule") {
+        atRules.push({
+          type: "property",
+          propertyName: rule.name,
+          line: InspectorUtils.getRelativeRuleLine(rule),
+          column: InspectorUtils.getRuleColumn(rule),
+        });
       }
     }
     return {
diff --git a/devtools/server/actors/watcher.js b/devtools/server/actors/watcher.js
index 935d33faa8..10de102229 100644
--- a/devtools/server/actors/watcher.js
+++ b/devtools/server/actors/watcher.js
@@ -11,13 +11,12 @@ const { TargetActorRegistry } = ChromeUtils.importESModule(
   "resource://devtools/server/actors/targets/target-actor-registry.sys.mjs",
   { global: "shared" }
 );
-const { WatcherRegistry } = ChromeUtils.importESModule(
-  "resource://devtools/server/actors/watcher/WatcherRegistry.sys.mjs",
-  // WatcherRegistry needs to be a true singleton and loads ActorManagerParent
+const { ParentProcessWatcherRegistry } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/ParentProcessWatcherRegistry.sys.mjs",
+  // ParentProcessWatcherRegistry needs to be a true singleton and loads ActorManagerParent
   // which also has to be a true singleton.
   { global: "shared" }
 );
-const Targets = require("resource://devtools/server/actors/targets/index.js");
 const { getAllBrowsingContextsForContext } = ChromeUtils.importESModule(
   "resource://devtools/server/actors/watcher/browsing-context-helpers.sys.mjs",
   { global: "contextual" }
@@ -26,28 +25,6 @@ const {
   SESSION_TYPES,
 } = require("resource://devtools/server/actors/watcher/session-context.js");
 
-const TARGET_HELPERS = {};
-loader.lazyRequireGetter(
-  TARGET_HELPERS,
-  Targets.TYPES.FRAME,
-  "resource://devtools/server/actors/watcher/target-helpers/frame-helper.js"
-);
-loader.lazyRequireGetter(
-  TARGET_HELPERS,
-  Targets.TYPES.PROCESS,
-  "resource://devtools/server/actors/watcher/target-helpers/process-helper.js"
-);
-loader.lazyRequireGetter(
-  TARGET_HELPERS,
-  Targets.TYPES.SERVICE_WORKER,
-  "devtools/server/actors/watcher/target-helpers/service-worker-helper"
-);
-loader.lazyRequireGetter(
-  TARGET_HELPERS,
-  Targets.TYPES.WORKER,
-  "resource://devtools/server/actors/watcher/target-helpers/worker-helper.js"
-);
-
 loader.lazyRequireGetter(
   this,
   "NetworkParentActor",
@@ -137,6 +114,14 @@ exports.WatcherActor = class WatcherActor extends Actor {
     // but there are certain cases when a new target is available before the
     // old target is destroyed.
     this._currentWindowGlobalTargets = new Map();
+
+    // The Browser Toolbox requires to load modules in a distinct compartment in order
+    // to be able to debug system compartments modules (most of Firefox internal codebase).
+    // This is a requirement coming from SpiderMonkey Debugger API and relates to the thread actor.
+    this._jsActorName =
+      sessionContext.type == SESSION_TYPES.ALL
+        ? "BrowserToolboxDevToolsProcess"
+        : "DevToolsProcess";
   }
 
   get sessionContext() {
@@ -176,16 +161,33 @@ exports.WatcherActor = class WatcherActor extends Actor {
   }
 
   destroy() {
-    // Force unwatching for all types, even if we weren't watching.
-    // This is fine as unwatchTarget is NOOP if we weren't already watching for this target type.
-    for (const targetType of Object.values(Targets.TYPES)) {
-      this.unwatchTargets(targetType);
+    // Only try to notify content processes if the watcher was in the registry.
+    // Otherwise it means that it wasn't connected to any process and the JS Process Actor
+    // wouldn't be registered.
+    if (ParentProcessWatcherRegistry.getWatcher(this.actorID)) {
+      // Emit one IPC message on destroy to all the processes
+      const domProcesses = ChromeUtils.getAllDOMProcesses();
+      for (const domProcess of domProcesses) {
+        domProcess.getActor(this._jsActorName).destroyWatcher({
+          watcherActorID: this.actorID,
+        });
+      }
     }
-    this.unwatchResources(Object.values(Resources.TYPES));
 
-    WatcherRegistry.unregisterWatcher(this);
+    // Ensure destroying all Resource Watcher instantiated in the parent process
+    Resources.unwatchResources(
+      this,
+      Resources.getParentProcessResourceTypes(Object.values(Resources.TYPES))
+    );
+
+    ParentProcessWatcherRegistry.unregisterWatcher(this.actorID);
 
-    // Destroy the actor at the end so that its actorID keeps being defined.
+    // In case the watcher actor is leaked, prevent leaking the browser window
+    this._browserElement = null;
+
+    // Destroy the actor in order to ensure destroying all its children actors.
+    // As this actor is a pool with children actors, when the transport/connection closes
+    // we expect all actors and its children to be destroyed.
     super.destroy();
   }
 
@@ -196,7 +198,7 @@ exports.WatcherActor = class WatcherActor extends Actor {
    *         Returns the list of currently watched resource types.
    */
   get sessionData() {
-    return WatcherRegistry.getSessionData(this);
+    return ParentProcessWatcherRegistry.getSessionData(this);
   }
 
   form() {
@@ -225,11 +227,44 @@ exports.WatcherActor = class WatcherActor extends Actor {
    *        Type of context to observe. See Targets.TYPES object.
    */
   async watchTargets(targetType) {
-    WatcherRegistry.watchTargets(this, targetType);
+    ParentProcessWatcherRegistry.watchTargets(this, targetType);
+
+    // When debugging a tab, ensure processing the top level target first
+    // (for now, other session context types are instantiating the top level target
+    // from the descriptor's getTarget method instead of the Watcher)
+    let topLevelTargetProcess;
+    if (this.sessionContext.type == SESSION_TYPES.BROWSER_ELEMENT) {
+      topLevelTargetProcess =
+        this.browserElement.browsingContext.currentWindowGlobal?.domProcess;
+      if (topLevelTargetProcess) {
+        await topLevelTargetProcess.getActor(this._jsActorName).watchTargets({
+          watcherActorID: this.actorID,
+          targetType,
+        });
+        // Stop execution if we were destroyed in the meantime
+        if (this.isDestroyed()) {
+          return;
+        }
+      }
+    }
 
-    const targetHelperModule = TARGET_HELPERS[targetType];
-    // Await the registration in order to ensure receiving the already existing targets
-    await targetHelperModule.createTargets(this);
+    // We have to reach out all the content processes as the page may navigate
+    // to any other content process when navigating to another origin.
+    // It may even run in the parent process when loading about:robots.
+    const domProcesses = ChromeUtils.getAllDOMProcesses();
+    const promises = [];
+    for (const domProcess of domProcesses) {
+      if (domProcess == topLevelTargetProcess) {
+        continue;
+      }
+      promises.push(
+        domProcess.getActor(this._jsActorName).watchTargets({
+          watcherActorID: this.actorID,
+          targetType,
+        })
+      );
+    }
+    await Promise.all(promises);
   }
 
   /**
@@ -242,7 +277,7 @@ exports.WatcherActor = class WatcherActor extends Actor {
    *        true when this is called as the result of a change to the devtools.browsertoolbox.scope pref
    */
   unwatchTargets(targetType, options = {}) {
-    const isWatchingTargets = WatcherRegistry.unwatchTargets(
+    const isWatchingTargets = ParentProcessWatcherRegistry.unwatchTargets(
       this,
       targetType,
       options
@@ -251,14 +286,20 @@ exports.WatcherActor = class WatcherActor extends Actor {
       return;
     }
 
-    const targetHelperModule = TARGET_HELPERS[targetType];
-    targetHelperModule.destroyTargets(this, options);
+    const domProcesses = ChromeUtils.getAllDOMProcesses();
+    for (const domProcess of domProcesses) {
+      domProcess.getActor(this._jsActorName).unwatchTargets({
+        watcherActorID: this.actorID,
+        targetType,
+        options,
+      });
+    }
 
     // Unregister the JS Actors if there is no more DevTools code observing any target/resource,
     // unless we're switching mode (having both condition at the same time should only
     // happen in tests).
     if (!options.isModeSwitching) {
-      WatcherRegistry.maybeUnregisterJSActors();
+      ParentProcessWatcherRegistry.maybeUnregisterJSActors();
     }
   }
 
@@ -301,7 +342,12 @@ exports.WatcherActor = class WatcherActor extends Actor {
       this._flushIframeTargets(actor.innerWindowId);
 
       if (this.sessionContext.type == SESSION_TYPES.BROWSER_ELEMENT) {
-        this.updateDomainSessionDataForServiceWorkers(actor.url);
+        // Ignore any pending exception as this request may be pending
+        // while the toolbox closes. And we don't want to delay target emission
+        // on this as this is a implementation detail.
+        this.updateDomainSessionDataForServiceWorkers(actor.url).catch(
+          () => {}
+        );
       }
     } else if (this._currentWindowGlobalTargets.has(actor.topInnerWindowId)) {
       // Emit the event immediately if the top-level target is already available
@@ -444,18 +490,18 @@ exports.WatcherActor = class WatcherActor extends Actor {
   }
 
   /**
-   * Try to retrieve a parent process TargetActor which is ignored by the
-   * TARGET_HELPERS. Examples:
-   * - top level target for the browser toolbox
-   * - xpcshell target for xpcshell debugging
+   * Try to retrieve Target Actors instantiated in the parent process which aren't
+   * instantiated via the Watcher actor (and its dependencies):
+   * - top level target for the browser toolboxes
+   * - xpcshell targets for xpcshell debugging
    *
    * See comment in `watchResources`.
    *
-   * @return {TargetActor|null} Matching target actor if any, null otherwise.
+   * @return {Set<TargetActor>} Matching target actors.
    */
-  getTargetActorInParentProcess() {
-    if (TargetActorRegistry.xpcShellTargetActor) {
-      return TargetActorRegistry.xpcShellTargetActor;
+  getTargetActorsInParentProcess() {
+    if (TargetActorRegistry.xpcShellTargetActors.size) {
+      return TargetActorRegistry.xpcShellTargetActors;
     }
 
     // Note: For browser-element debugging, the WindowGlobalTargetActor returned here is created
@@ -467,12 +513,18 @@ exports.WatcherActor = class WatcherActor extends Actor {
 
     switch (this.sessionContext.type) {
       case "all":
-        return actors.find(actor => actor.typeName === "parentProcessTarget");
+        const parentProcessTargetActor = actors.find(
+          actor => actor.typeName === "parentProcessTarget"
+        );
+        if (parentProcessTargetActor) {
+          return new Set([parentProcessTargetActor]);
+        }
+        return new Set();
       case "browser-element":
       case "webextension":
         // All target actors for browser-element and webextension sessions
         // should be created using the JS Window actors.
-        return null;
+        return new Set();
       default:
         throw new Error(
           "Unsupported session context type: " + this.sessionContext.type
@@ -497,41 +549,32 @@ exports.WatcherActor = class WatcherActor extends Actor {
     );
 
     // Bail out early if all resources were watched from parent process.
-    // In this scenario, we do not need to update these resource types in the WatcherRegistry
+    // In this scenario, we do not need to update these resource types in the ParentProcessWatcherRegistry
     // as targets do not care about them.
     if (!Resources.hasResourceTypesForTargets(resourceTypes)) {
       return;
     }
 
-    WatcherRegistry.watchResources(this, resourceTypes);
+    ParentProcessWatcherRegistry.watchResources(this, resourceTypes);
 
-    // Fetch resources from all existing targets
-    for (const targetType in TARGET_HELPERS) {
-      // We process frame targets even if we aren't watching them,
-      // because frame target helper codepath handles the top level target, if it runs in the *content* process.
-      // It will do another check to `isWatchingTargets(FRAME)` internally.
-      // Note that the workaround at the end of this method, using TargetActorRegistry
-      // is specific to top level target running in the *parent* process.
-      if (
-        !WatcherRegistry.isWatchingTargets(this, targetType) &&
-        targetType != Targets.TYPES.FRAME
-      ) {
-        continue;
-      }
-      const targetResourceTypes = Resources.getResourceTypesForTargetType(
-        resourceTypes,
-        targetType
+    const promises = [];
+    const domProcesses = ChromeUtils.getAllDOMProcesses();
+    for (const domProcess of domProcesses) {
+      promises.push(
+        domProcess.getActor(this._jsActorName).addOrSetSessionDataEntry({
+          watcherActorID: this.actorID,
+          sessionContext: this.sessionContext,
+          type: "resources",
+          entries: resourceTypes,
+          updateType: "add",
+        })
       );
-      if (!targetResourceTypes.length) {
-        continue;
-      }
-      const targetHelperModule = TARGET_HELPERS[targetType];
-      await targetHelperModule.addOrSetSessionDataEntry({
-        watcher: this,
-        type: "resources",
-        entries: targetResourceTypes,
-        updateType: "add",
-      });
+    }
+    await Promise.all(promises);
+
+    // Stop execution if we were destroyed in the meantime
+    if (this.isDestroyed()) {
+      return;
     }
 
     /*
@@ -551,8 +594,8 @@ exports.WatcherActor = class WatcherActor extends Actor {
      * We will eventually get rid of this code once all targets are properly supported by
      * the Watcher Actor and we have target helpers for all of them.
      */
-    const targetActor = this.getTargetActorInParentProcess();
-    if (targetActor) {
+    const targetActors = this.getTargetActorsInParentProcess();
+    for (const targetActor of targetActors) {
       const targetActorResourceTypes = Resources.getResourceTypesForTargetType(
         resourceTypes,
         targetActor.targetType
@@ -581,13 +624,13 @@ exports.WatcherActor = class WatcherActor extends Actor {
     );
 
     // Bail out early if all resources were all watched from parent process.
-    // In this scenario, we do not need to update these resource types in the WatcherRegistry
+    // In this scenario, we do not need to update these resource types in the ParentProcessWatcherRegistry
     // as targets do not care about them.
     if (!Resources.hasResourceTypesForTargets(resourceTypes)) {
       return;
     }
 
-    const isWatchingResources = WatcherRegistry.unwatchResources(
+    const isWatchingResources = ParentProcessWatcherRegistry.unwatchResources(
       this,
       resourceTypes
     );
@@ -598,34 +641,20 @@ exports.WatcherActor = class WatcherActor extends Actor {
     // Prevent trying to unwatch when the related BrowsingContext has already
     // been destroyed
     if (!this.isContextDestroyed()) {
-      for (const targetType in TARGET_HELPERS) {
-        // Frame target helper handles the top level target, if it runs in the content process
-        // so we should always process it. It does a second check to isWatchingTargets.
-        if (
-          !WatcherRegistry.isWatchingTargets(this, targetType) &&
-          targetType != Targets.TYPES.FRAME
-        ) {
-          continue;
-        }
-        const targetResourceTypes = Resources.getResourceTypesForTargetType(
-          resourceTypes,
-          targetType
-        );
-        if (!targetResourceTypes.length) {
-          continue;
-        }
-        const targetHelperModule = TARGET_HELPERS[targetType];
-        targetHelperModule.removeSessionDataEntry({
-          watcher: this,
+      const domProcesses = ChromeUtils.getAllDOMProcesses();
+      for (const domProcess of domProcesses) {
+        domProcess.getActor(this._jsActorName).removeSessionDataEntry({
+          watcherActorID: this.actorID,
+          sessionContext: this.sessionContext,
           type: "resources",
-          entries: targetResourceTypes,
+          entries: resourceTypes,
         });
       }
     }
 
     // See comment in watchResources.
-    const targetActor = this.getTargetActorInParentProcess();
-    if (targetActor) {
+    const targetActors = this.getTargetActorsInParentProcess();
+    for (const targetActor of targetActors) {
       const targetActorResourceTypes = Resources.getResourceTypesForTargetType(
         resourceTypes,
         targetActor.targetType
@@ -634,7 +663,7 @@ exports.WatcherActor = class WatcherActor extends Actor {
     }
 
     // Unregister the JS Window Actor if there is no more DevTools code observing any target/resource
-    WatcherRegistry.maybeUnregisterJSActors();
+    ParentProcessWatcherRegistry.maybeUnregisterJSActors();
   }
 
   clearResources(resourceTypes) {
@@ -729,34 +758,36 @@ exports.WatcherActor = class WatcherActor extends Actor {
    *        "set" will update the data set with the new entries.
    */
   async addOrSetDataEntry(type, entries, updateType) {
-    WatcherRegistry.addOrSetSessionDataEntry(this, type, entries, updateType);
-
-    await Promise.all(
-      Object.values(Targets.TYPES)
-        .filter(
-          targetType =>
-            // We process frame targets even if we aren't watching them,
-            // because frame target helper codepath handles the top level target, if it runs in the *content* process.
-            // It will do another check to `isWatchingTargets(FRAME)` internally.
-            // Note that the workaround at the end of this method, using TargetActorRegistry
-            // is specific to top level target running in the *parent* process.
-            WatcherRegistry.isWatchingTargets(this, targetType) ||
-            targetType === Targets.TYPES.FRAME
-        )
-        .map(async targetType => {
-          const targetHelperModule = TARGET_HELPERS[targetType];
-          await targetHelperModule.addOrSetSessionDataEntry({
-            watcher: this,
-            type,
-            entries,
-            updateType,
-          });
-        })
+    ParentProcessWatcherRegistry.addOrSetSessionDataEntry(
+      this,
+      type,
+      entries,
+      updateType
     );
 
+    const promises = [];
+    const domProcesses = ChromeUtils.getAllDOMProcesses();
+    for (const domProcess of domProcesses) {
+      promises.push(
+        domProcess.getActor(this._jsActorName).addOrSetSessionDataEntry({
+          watcherActorID: this.actorID,
+          sessionContext: this.sessionContext,
+          type,
+          entries,
+          updateType,
+        })
+      );
+    }
+    await Promise.all(promises);
+
+    // Stop execution if we were destroyed in the meantime
+    if (this.isDestroyed()) {
+      return;
+    }
+
     // See comment in watchResources
-    const targetActor = this.getTargetActorInParentProcess();
-    if (targetActor) {
+    const targetActors = this.getTargetActorsInParentProcess();
+    for (const targetActor of targetActors) {
       await targetActor.addOrSetSessionDataEntry(
         type,
         entries,
@@ -777,27 +808,21 @@ exports.WatcherActor = class WatcherActor extends Actor {
    *        List of values to remove from this data type.
    */
   removeDataEntry(type, entries) {
-    WatcherRegistry.removeSessionDataEntry(this, type, entries);
-
-    Object.values(Targets.TYPES)
-      .filter(
-        targetType =>
-          // See comment in addOrSetDataEntry
-          WatcherRegistry.isWatchingTargets(this, targetType) ||
-          targetType === Targets.TYPES.FRAME
-      )
-      .forEach(targetType => {
-        const targetHelperModule = TARGET_HELPERS[targetType];
-        targetHelperModule.removeSessionDataEntry({
-          watcher: this,
-          type,
-          entries,
-        });
+    ParentProcessWatcherRegistry.removeSessionDataEntry(this, type, entries);
+
+    const domProcesses = ChromeUtils.getAllDOMProcesses();
+    for (const domProcess of domProcesses) {
+      domProcess.getActor(this._jsActorName).removeSessionDataEntry({
+        watcherActorID: this.actorID,
+        sessionContext: this.sessionContext,
+        type,
+        entries,
       });
+    }
 
     // See comment in addOrSetDataEntry
-    const targetActor = this.getTargetActorInParentProcess();
-    if (targetActor) {
+    const targetActors = this.getTargetActorsInParentProcess();
+    for (const targetActor of targetActors) {
       targetActor.removeSessionDataEntry(type, entries);
     }
   }
@@ -827,35 +852,13 @@ exports.WatcherActor = class WatcherActor extends Actor {
       host = new URL(newTargetUrl).host;
     } catch (e) {}
 
-    WatcherRegistry.addOrSetSessionDataEntry(
+    ParentProcessWatcherRegistry.addOrSetSessionDataEntry(
       this,
       "browser-element-host",
       [host],
       "set"
     );
 
-    // This SessionData attribute is only used when debugging service workers.
-    // Avoid instantiating the JS Process Actors if we aren't watching for SW,
-    // or if we aren't watching for them just yet.
-    // But still update the WatcherRegistry, so that when we start watching
-    // and instantiate the target, the host will be set to the right value.
-    //
-    // Note that it is very important to avoid calling Service worker target helper's
-    // addOrSetSessionDataEntry. Otherwise, when we aren't watching for SW at all,
-    // we won't call destroyTargets on watcher actor destruction,
-    // and as a consequence never unregister the js process actor.
-    if (
-      !WatcherRegistry.isWatchingTargets(this, Targets.TYPES.SERVICE_WORKER)
-    ) {
-      return;
-    }
-
-    const targetHelperModule = TARGET_HELPERS[Targets.TYPES.SERVICE_WORKER];
-    await targetHelperModule.addOrSetSessionDataEntry({
-      watcher: this,
-      type: "browser-element-host",
-      entries: [host],
-      updateType: "set",
-    });
+    return this.addOrSetDataEntry("browser-element-host", [host], "set");
   }
 };
diff --git a/devtools/server/actors/watcher/WatcherRegistry.sys.mjs b/devtools/server/actors/watcher/ParentProcessWatcherRegistry.sys.mjs
index ac8bc7f0c8..e9b3a9d50d 100644
--- a/devtools/server/actors/watcher/WatcherRegistry.sys.mjs
+++ b/devtools/server/actors/watcher/ParentProcessWatcherRegistry.sys.mjs
@@ -24,10 +24,9 @@
  * while from the content process, we will read `sharedData` directly.
  */
 
-import { ActorManagerParent } from "resource://gre/modules/ActorManagerParent.sys.mjs";
-
-const { SessionDataHelpers } = ChromeUtils.import(
-  "resource://devtools/server/actors/watcher/SessionDataHelpers.jsm"
+const { SessionDataHelpers } = ChromeUtils.importESModule(
+  "resource://devtools/server/actors/watcher/SessionDataHelpers.sys.mjs",
+  { global: "contextual" }
 );
 
 const { SUPPORTED_DATA } = SessionDataHelpers;
@@ -68,7 +67,7 @@ function persistMapToSharedData() {
   Services.ppmm.sharedData.flush();
 }
 
-export const WatcherRegistry = {
+export const ParentProcessWatcherRegistry = {
   /**
    * Tells if a given watcher currently watches for a given target type.
    *
@@ -178,13 +177,16 @@ export const WatcherRegistry = {
       updateType
     );
 
+    // Flush sharedData before registering the JS Actors as it is used
+    // during their instantiation.
+    persistMapToSharedData();
+
     // Register the JS Window Actor the first time we start watching for something (e.g. resource, target, …).
-    registerJSWindowActor();
-    if (sessionData?.targets?.includes("process")) {
+    if (watcher.sessionContext.type == "all") {
+      registerBrowserToolboxJSProcessActor();
+    } else {
       registerJSProcessActor();
     }
-
-    persistMapToSharedData();
   },
 
   /**
@@ -245,9 +247,9 @@ export const WatcherRegistry = {
    * if we remove all entries. But we aren't removing all breakpoints.
    * So here, we force clearing any reference to the watcher actor when it destroys.
    */
-  unregisterWatcher(watcher) {
-    sessionDataByWatcherActor.delete(watcher.actorID);
-    watcherActors.delete(watcher.actorID);
+  unregisterWatcher(watcherActorID) {
+    sessionDataByWatcherActor.delete(watcherActorID);
+    watcherActors.delete(watcherActorID);
     this.maybeUnregisterJSActors();
   },
 
@@ -256,7 +258,7 @@ export const WatcherRegistry = {
    */
   maybeUnregisterJSActors() {
     if (sessionDataByWatcherActor.size == 0) {
-      unregisterJSWindowActor();
+      unregisterBrowserToolboxJSProcessActor();
       unregisterJSProcessActor();
     }
   },
@@ -334,74 +336,9 @@ export const WatcherRegistry = {
   },
 };
 
-// Boolean flag to know if the DevToolsFrame JS Window Actor is currently registered
-let isJSWindowActorRegistered = false;
-
-/**
- * Register the JSWindowActor pair "DevToolsFrame".
- *
- * We should call this method before we try to use this JS Window Actor from the parent process
- * (via `WindowGlobal.getActor("DevToolsFrame")` or `WindowGlobal.getActor("DevToolsWorker")`).
- * Also, registering it will automatically force spawing the content process JSWindow Actor
- * anytime a new document is opened (via DOMWindowCreated event).
- */
-
-const JSWindowActorsConfig = {
-  DevToolsFrame: {
-    parent: {
-      esModuleURI:
-        "resource://devtools/server/connectors/js-window-actor/DevToolsFrameParent.sys.mjs",
-    },
-    child: {
-      esModuleURI:
-        "resource://devtools/server/connectors/js-window-actor/DevToolsFrameChild.sys.mjs",
-      events: {
-        DOMWindowCreated: {},
-        DOMDocElementInserted: {},
-        pageshow: {},
-        pagehide: {},
-      },
-    },
-    allFrames: true,
-  },
-  DevToolsWorker: {
-    parent: {
-      esModuleURI:
-        "resource://devtools/server/connectors/js-window-actor/DevToolsWorkerParent.sys.mjs",
-    },
-    child: {
-      esModuleURI:
-        "resource://devtools/server/connectors/js-window-actor/DevToolsWorkerChild.sys.mjs",
-      events: {
-        DOMWindowCreated: {},
-      },
-    },
-    allFrames: true,
-  },
-};
-
-function registerJSWindowActor() {
-  if (isJSWindowActorRegistered) {
-    return;
-  }
-  isJSWindowActorRegistered = true;
-  ActorManagerParent.addJSWindowActors(JSWindowActorsConfig);
-}
-
-function unregisterJSWindowActor() {
-  if (!isJSWindowActorRegistered) {
-    return;
-  }
-  isJSWindowActorRegistered = false;
-
-  for (const JSWindowActorName of Object.keys(JSWindowActorsConfig)) {
-    // ActorManagerParent doesn't expose a "removeActors" method, but it would be equivalent to that:
-    ChromeUtils.unregisterWindowActor(JSWindowActorName);
-  }
-}
-
 // Boolean flag to know if the DevToolsProcess JS Process Actor is currently registered
 let isJSProcessActorRegistered = false;
+let isBrowserToolboxJSProcessActorRegistered = false;
 
 const JSProcessActorConfig = {
   parent: {
@@ -419,7 +356,11 @@ const JSProcessActorConfig = {
   // The parent process is handled very differently from content processes
   // This uses the ParentProcessTarget which inherits from BrowsingContextTarget
   // and is, for now, manually created by the descriptor as the top level target.
-  includeParent: false,
+  includeParent: true,
+};
+
+const BrowserToolboxJSProcessActorConfig = {
+  ...JSProcessActorConfig,
 
   // This JS Process Actor is used to bootstrap DevTools code debugging the privileged code
   // in content processes. The privileged code runs in the "shared JSM global" (See mozJSModuleLoader).
@@ -432,7 +373,7 @@ const JSProcessActorConfig = {
 };
 
 const PROCESS_SCRIPT_URL =
-  "resource://devtools/server/actors/watcher/target-helpers/content-process-jsprocessactor-startup.js";
+  "resource://devtools/server/connectors/js-process-actor/content-process-jsprocessactor-startup.js";
 
 function registerJSProcessActor() {
   if (isJSProcessActorRegistered) {
@@ -447,6 +388,22 @@ function registerJSProcessActor() {
   Services.ppmm.loadProcessScript(PROCESS_SCRIPT_URL, true);
 }
 
+function registerBrowserToolboxJSProcessActor() {
+  if (isBrowserToolboxJSProcessActorRegistered) {
+    return;
+  }
+  isBrowserToolboxJSProcessActorRegistered = true;
+  ChromeUtils.registerProcessActor(
+    "BrowserToolboxDevToolsProcess",
+    BrowserToolboxJSProcessActorConfig
+  );
+
+  // There is no good observer service notification we can listen to to instantiate the JSProcess Actor
+  // as soon as the process start.
+  // So manually spawn our JSProcessActor from a process script emitting a custom observer service notification...
+  Services.ppmm.loadProcessScript(PROCESS_SCRIPT_URL, true);
+}
+
 function unregisterJSProcessActor() {
   if (!isJSProcessActorRegistered) {
     return;
@@ -457,5 +414,24 @@ function unregisterJSProcessActor() {
   } catch (e) {
     // If any pending query was still ongoing, this would throw
   }
+  if (isBrowserToolboxJSProcessActorRegistered) {
+    return;
+  }
+  Services.ppmm.removeDelayedProcessScript(PROCESS_SCRIPT_URL);
+}
+
+function unregisterBrowserToolboxJSProcessActor() {
+  if (!isBrowserToolboxJSProcessActorRegistered) {
+    return;
+  }
+  isBrowserToolboxJSProcessActorRegistered = false;
+  try {
+    ChromeUtils.unregisterProcessActor("BrowserToolboxDevToolsProcess");
+  } catch (e) {
+    // If any pending query was still ongoing, this would throw
+  }
+  if (isJSProcessActorRegistered) {
+    return;
+  }
   Services.ppmm.removeDelayedProcessScript(PROCESS_SCRIPT_URL);
 }
diff --git a/devtools/server/actors/watcher/SessionDataHelpers.jsm b/devtools/server/actors/watcher/SessionDataHelpers.sys.mjs
index c70df1744f..def31b77a8 100644
--- a/devtools/server/actors/watcher/SessionDataHelpers.jsm
+++ b/devtools/server/actors/watcher/SessionDataHelpers.sys.mjs
@@ -2,49 +2,30 @@
  * 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";
-
 /**
- * Helper module alongside WatcherRegistry, which focus on updating the "sessionData" object.
+ * Helper module alongside ParentProcessWatcherRegistry, which focus on updating the "sessionData" object.
  * This object is shared across processes and threads and have to be maintained in all these runtimes.
  */
 
-var EXPORTED_SYMBOLS = ["SessionDataHelpers"];
-
 const lazy = {};
+ChromeUtils.defineESModuleGetters(
+  lazy,
+  {
+    validateBreakpointLocation:
+      "resource://devtools/shared/validate-breakpoint.sys.mjs",
+  },
+  { global: "contextual" }
+);
 
-if (typeof module == "object") {
-  // Allow this JSM to also be loaded as a CommonJS module
-  // Because this module is used from the worker thread,
-  // (via target-actor-mixin), and workers can't load JSMs via ChromeUtils.import.
-  loader.lazyRequireGetter(
-    lazy,
-    "validateBreakpointLocation",
-    "resource://devtools/shared/validate-breakpoint.jsm",
-    true
+ChromeUtils.defineLazyGetter(lazy, "validateEventBreakpoint", () => {
+  const { loader } = ChromeUtils.importESModule(
+    "resource://devtools/shared/loader/Loader.sys.mjs",
+    { global: "contextual" }
   );
-
-  loader.lazyRequireGetter(
-    lazy,
-    "validateEventBreakpoint",
-    "resource://devtools/server/actors/utils/event-breakpoints.js",
-    true
-  );
-} else {
-  ChromeUtils.defineLazyGetter(lazy, "validateBreakpointLocation", () => {
-    return ChromeUtils.import(
-      "resource://devtools/shared/validate-breakpoint.jsm"
-    ).validateBreakpointLocation;
-  });
-  ChromeUtils.defineLazyGetter(lazy, "validateEventBreakpoint", () => {
-    const { loader } = ChromeUtils.importESModule(
-      "resource://devtools/shared/loader/Loader.sys.mjs"
-    );
-    return loader.require(
-      "resource://devtools/server/actors/utils/event-breakpoints.js"
-    ).validateEventBreakpoint;
-  });
-}
+  return loader.require(
+    "resource://devtools/server/actors/utils/event-breakpoints.js"
+  ).validateEventBreakpoint;
+});
 
 // List of all arrays stored in `sessionData`, which are replicated across processes and threads
 const SUPPORTED_DATA = {
@@ -151,7 +132,7 @@ function idFunction(v) {
   return v;
 }
 
-const SessionDataHelpers = {
+export const SessionDataHelpers = {
   SUPPORTED_DATA,
 
   /**
@@ -235,10 +216,3 @@ const SessionDataHelpers = {
     return true;
   },
 };
-
-// Allow this JSM to also be loaded as a CommonJS module
-// Because this module is used from the worker thread,
-// (via target-actor-mixin), and workers can't load JSMs.
-if (typeof module == "object") {
-  module.exports.SessionDataHelpers = SessionDataHelpers;
-}
diff --git a/devtools/server/actors/watcher/browsing-context-helpers.sys.mjs b/devtools/server/actors/watcher/browsing-context-helpers.sys.mjs
index d52cbc5708..cd34c75760 100644
--- a/devtools/server/actors/watcher/browsing-context-helpers.sys.mjs
+++ b/devtools/server/actors/watcher/browsing-context-helpers.sys.mjs
@@ -382,7 +382,7 @@ export function getAllBrowsingContextsForContext(
       sessionContext.browserId
     );
     // topBrowsingContext can be null if getCurrentTopByBrowserId is called for a tab that is unloaded.
-    if (topBrowsingContext) {
+    if (topBrowsingContext?.embedderElement) {
       // Unfortunately, getCurrentTopByBrowserId is subject to race conditions and may refer to a BrowsingContext
       // that already navigated away.
       // Query the current "live" BrowsingContext by going through the embedder element (i.e. the <browser>/<iframe> element)
diff --git a/devtools/server/actors/watcher/moz.build b/devtools/server/actors/watcher/moz.build
index 46a9d89718..47d08e8780 100644
--- a/devtools/server/actors/watcher/moz.build
+++ b/devtools/server/actors/watcher/moz.build
@@ -4,13 +4,9 @@
 # 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/.
 
-DIRS += [
-    "target-helpers",
-]
-
 DevToolsModules(
     "browsing-context-helpers.sys.mjs",
+    "ParentProcessWatcherRegistry.sys.mjs",
     "session-context.js",
-    "SessionDataHelpers.jsm",
-    "WatcherRegistry.sys.mjs",
+    "SessionDataHelpers.sys.mjs",
 )
diff --git a/devtools/server/actors/watcher/target-helpers/content-process-jsprocessactor-startup.js b/devtools/server/actors/watcher/target-helpers/content-process-jsprocessactor-startup.js
deleted file mode 100644
index 1765bcc66c..0000000000
--- a/devtools/server/actors/watcher/target-helpers/content-process-jsprocessactor-startup.js
+++ /dev/null
@@ -1,26 +0,0 @@
-/* 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";
-
-const { setTimeout } = ChromeUtils.importESModule(
-  "resource://gre/modules/Timer.sys.mjs"
-);
-
-/*
-   We can't spawn the JSProcessActor right away and have to spin the event loop.
-   Otherwise it isn't registered yet and isn't listening to observer service.
-   Could it be the reason why JSProcessActor aren't spawn via process actor option's child.observers notifications ??
-*/
-setTimeout(function () {
-  /*
-    This notification is registered in DevToolsServiceWorker JS process actor's options's `observers` attribute
-    and will force the JS Process actor to be instantiated in all processes.
-  */
-  Services.obs.notifyObservers(null, "init-devtools-content-process-actor");
-  /*
-    Instead of using observer service, we could also manually call some method of the actor:
-    ChromeUtils.domProcessChild.getActor("DevToolsProcess").observe(null, "foo");
-  */
-}, 0);
diff --git a/devtools/server/actors/watcher/target-helpers/frame-helper.js b/devtools/server/actors/watcher/target-helpers/frame-helper.js
deleted file mode 100644
index 18d4d8f92e..0000000000
--- a/devtools/server/actors/watcher/target-helpers/frame-helper.js
+++ /dev/null
@@ -1,330 +0,0 @@
-/* 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";
-
-const { WatcherRegistry } = ChromeUtils.importESModule(
-  "resource://devtools/server/actors/watcher/WatcherRegistry.sys.mjs",
-  // WatcherRegistry needs to be a true singleton and loads ActorManagerParent
-  // which also has to be a true singleton.
-  { global: "shared" }
-);
-const { WindowGlobalLogger } = ChromeUtils.importESModule(
-  "resource://devtools/server/connectors/js-window-actor/WindowGlobalLogger.sys.mjs",
-  { global: "contextual" }
-);
-const Targets = require("resource://devtools/server/actors/targets/index.js");
-
-const browsingContextAttachedObserverByWatcher = new Map();
-
-/**
- * Force creating targets for all existing BrowsingContext, that, for a given Watcher Actor.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to watch for new targets.
- */
-async function createTargets(watcher) {
-  // Go over all existing BrowsingContext in order to:
-  // - Force the instantiation of a DevToolsFrameChild
-  // - Have the DevToolsFrameChild to spawn the WindowGlobalTargetActor
-
-  // If we have a browserElement, set the watchedByDevTools flag on its related browsing context
-  // TODO: We should also set the flag for the "parent process" browsing context when we're
-  // in the browser toolbox. This is blocked by Bug 1675763, and should be handled as part
-  // of Bug 1709529.
-  if (watcher.sessionContext.type == "browser-element") {
-    // The `watchedByDevTools` enables gecko behavior tied to this flag, such as:
-    //  - reporting the contents of HTML loaded in the docshells
-    //  - capturing stacks for the network monitor.
-    watcher.browserElement.browsingContext.watchedByDevTools = true;
-  }
-
-  if (!browsingContextAttachedObserverByWatcher.has(watcher)) {
-    // We store the browserId here as watcher.browserElement.browserId can momentary be
-    // set to 0 when there's a navigation to a new browsing context.
-    const browserId = watcher.sessionContext.browserId;
-    const onBrowsingContextAttached = browsingContext => {
-      // We want to set watchedByDevTools on new top-level browsing contexts:
-      // - in the case of the BrowserToolbox/BrowserConsole, that would be the browsing
-      //   contexts of all the tabs we want to handle.
-      // - for the regular toolbox, browsing context that are being created when navigating
-      //   to a page that forces a new browsing context.
-      // Then BrowsingContext will propagate to all the tree of children BrowsingContext's.
-      if (
-        !browsingContext.parent &&
-        (watcher.sessionContext.type != "browser-element" ||
-          browserId === browsingContext.browserId)
-      ) {
-        browsingContext.watchedByDevTools = true;
-      }
-    };
-    Services.obs.addObserver(
-      onBrowsingContextAttached,
-      "browsing-context-attached"
-    );
-    // We store the observer so we can retrieve it elsewhere (e.g. for removal in destroyTargets).
-    browsingContextAttachedObserverByWatcher.set(
-      watcher,
-      onBrowsingContextAttached
-    );
-  }
-
-  if (
-    watcher.sessionContext.isServerTargetSwitchingEnabled &&
-    watcher.sessionContext.type == "browser-element"
-  ) {
-    // If server side target switching is enabled, process the top level browsing context first,
-    // so that we guarantee it is notified to the client first.
-    // If it is disabled, the top level target will be created from the client instead.
-    await createTargetForBrowsingContext({
-      watcher,
-      browsingContext: watcher.browserElement.browsingContext,
-      retryOnAbortError: true,
-    });
-  }
-
-  const browsingContexts = watcher.getAllBrowsingContexts().filter(
-    // Filter out the top browsing context we just processed.
-    browsingContext =>
-      browsingContext != watcher.browserElement?.browsingContext
-  );
-  // Await for the all the queries in order to resolve only *after* we received all
-  // already available targets.
-  // i.e. each call to `createTargetForBrowsingContext` should end up emitting
-  // a target-available-form event via the WatcherActor.
-  await Promise.allSettled(
-    browsingContexts.map(browsingContext =>
-      createTargetForBrowsingContext({ watcher, browsingContext })
-    )
-  );
-}
-
-/**
- * (internal helper method) Force creating the target actor for a given BrowsingContext.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to watch for new targets.
- * @param BrowsingContext browsingContext
- *        The context for which a target should be created.
- * @param Boolean retryOnAbortError
- *        Set to true to retry creating existing targets when receiving an AbortError.
- *        An AbortError is sent when the JSWindowActor pair was destroyed before the query
- *        was complete, which can happen if the document navigates while the query is pending.
- */
-async function createTargetForBrowsingContext({
-  watcher,
-  browsingContext,
-  retryOnAbortError = false,
-}) {
-  logWindowGlobal(browsingContext.currentWindowGlobal, "Existing WindowGlobal");
-
-  // We need to set the watchedByDevTools flag on all top-level browsing context. In the
-  // case of a content toolbox, this is done in the tab descriptor, but when we're in the
-  // browser toolbox, such descriptor is not created.
-  // Then BrowsingContext will propagate to all the tree of children BbrowsingContext's.
-  if (!browsingContext.parent) {
-    browsingContext.watchedByDevTools = true;
-  }
-
-  try {
-    await browsingContext.currentWindowGlobal
-      .getActor("DevToolsFrame")
-      .instantiateTarget({
-        watcherActorID: watcher.actorID,
-        connectionPrefix: watcher.conn.prefix,
-        sessionContext: watcher.sessionContext,
-        sessionData: watcher.sessionData,
-      });
-  } catch (e) {
-    console.warn(
-      "Failed to create DevTools Frame target for browsingContext",
-      browsingContext.id,
-      ": ",
-      e,
-      retryOnAbortError ? "retrying" : ""
-    );
-    if (retryOnAbortError && e.name === "AbortError") {
-      await createTargetForBrowsingContext({
-        watcher,
-        browsingContext,
-        retryOnAbortError,
-      });
-    } else {
-      throw e;
-    }
-  }
-}
-
-/**
- * Force destroying all BrowsingContext targets which were related to a given watcher.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to stop watching for new targets.
- * @param {object} options
- * @param {boolean} options.isModeSwitching
- *        true when this is called as the result of a change to the devtools.browsertoolbox.scope pref
- */
-function destroyTargets(watcher, options) {
-  // Go over all existing BrowsingContext in order to destroy all targets
-  const browsingContexts = watcher.getAllBrowsingContexts();
-
-  for (const browsingContext of browsingContexts) {
-    logWindowGlobal(
-      browsingContext.currentWindowGlobal,
-      "Existing WindowGlobal"
-    );
-
-    if (!browsingContext.parent) {
-      browsingContext.watchedByDevTools = false;
-    }
-
-    browsingContext.currentWindowGlobal
-      .getActor("DevToolsFrame")
-      .destroyTarget({
-        watcherActorID: watcher.actorID,
-        sessionContext: watcher.sessionContext,
-        options,
-      });
-  }
-
-  if (watcher.sessionContext.type == "browser-element") {
-    watcher.browserElement.browsingContext.watchedByDevTools = false;
-  }
-
-  if (browsingContextAttachedObserverByWatcher.has(watcher)) {
-    Services.obs.removeObserver(
-      browsingContextAttachedObserverByWatcher.get(watcher),
-      "browsing-context-attached"
-    );
-    browsingContextAttachedObserverByWatcher.delete(watcher);
-  }
-}
-
-/**
- * Go over all existing BrowsingContext in order to communicate about new data entries
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to stop watching for new targets.
- * @param string type
- *        The type of data to be added
- * @param Array<Object> entries
- *        The values to be added to this type of data
- * @param String updateType
- *        "add" will only add the new entries in the existing data set.
- *        "set" will update the data set with the new entries.
- */
-async function addOrSetSessionDataEntry({
-  watcher,
-  type,
-  entries,
-  updateType,
-}) {
-  const browsingContexts = getWatchingBrowsingContexts(watcher);
-  const promises = [];
-  for (const browsingContext of browsingContexts) {
-    logWindowGlobal(
-      browsingContext.currentWindowGlobal,
-      "Existing WindowGlobal"
-    );
-
-    const promise = browsingContext.currentWindowGlobal
-      .getActor("DevToolsFrame")
-      .addOrSetSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        sessionContext: watcher.sessionContext,
-        type,
-        entries,
-        updateType,
-      });
-    promises.push(promise);
-  }
-  // Await for the queries in order to try to resolve only *after* the remote code processed the new data
-  return Promise.all(promises);
-}
-
-/**
- * Notify all existing frame targets that some data entries have been removed
- *
- * See addOrSetSessionDataEntry for argument documentation.
- */
-function removeSessionDataEntry({ watcher, type, entries }) {
-  const browsingContexts = getWatchingBrowsingContexts(watcher);
-  for (const browsingContext of browsingContexts) {
-    logWindowGlobal(
-      browsingContext.currentWindowGlobal,
-      "Existing WindowGlobal"
-    );
-
-    browsingContext.currentWindowGlobal
-      .getActor("DevToolsFrame")
-      .removeSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        sessionContext: watcher.sessionContext,
-        type,
-        entries,
-      });
-  }
-}
-
-module.exports = {
-  createTargets,
-  destroyTargets,
-  addOrSetSessionDataEntry,
-  removeSessionDataEntry,
-};
-
-/**
- * Return the list of BrowsingContexts which should be targeted in order to communicate
- * updated session data.
- *
- * @param WatcherActor watcher
- *        The watcher actor will be used to know which target we debug
- *        and what BrowsingContext should be considered.
- */
-function getWatchingBrowsingContexts(watcher) {
-  // If we are watching for additional frame targets, it means that the multiprocess or fission mode is enabled,
-  // either for a content toolbox or a BrowserToolbox via scope set to everything.
-  const watchingAdditionalTargets = WatcherRegistry.isWatchingTargets(
-    watcher,
-    Targets.TYPES.FRAME
-  );
-  if (watchingAdditionalTargets) {
-    return watcher.getAllBrowsingContexts();
-  }
-  // By default, when we are no longer watching for frame targets, we should no longer try to
-  // communicate with any browsing-context. But.
-  //
-  // For "browser-element" debugging, all targets are provided by watching by watching for frame targets.
-  // So, when we are no longer watching for frame, we don't expect to have any frame target to talk to.
-  // => we should no longer reach any browsing context.
-  //
-  // For "all" (=browser toolbox), there is only the special ParentProcessTargetActor we might want to return here.
-  // But this is actually handled by the WatcherActor which uses `WatcherActor.getTargetActorInParentProcess` to convey session data.
-  // => we should no longer reach any browsing context.
-  //
-  // For "webextension" debugging, there is the special WebExtensionTargetActor, which doesn't run in the parent process,
-  // so that we can't rely on the same code as the browser toolbox.
-  // => we should always reach out this particular browsing context.
-  if (watcher.sessionContext.type == "webextension") {
-    const browsingContext = BrowsingContext.get(
-      watcher.sessionContext.addonBrowsingContextID
-    );
-    // The add-on browsing context may be destroying, in which case we shouldn't try to communicate with it
-    if (browsingContext.currentWindowGlobal) {
-      return [browsingContext];
-    }
-  }
-  return [];
-}
-
-// Set to true to log info about about WindowGlobal's being watched.
-const DEBUG = false;
-
-function logWindowGlobal(windowGlobal, message) {
-  if (!DEBUG) {
-    return;
-  }
-
-  WindowGlobalLogger.logWindowGlobal(windowGlobal, message);
-}
diff --git a/devtools/server/actors/watcher/target-helpers/moz.build b/devtools/server/actors/watcher/target-helpers/moz.build
deleted file mode 100644
index 3b00f0ef47..0000000000
--- a/devtools/server/actors/watcher/target-helpers/moz.build
+++ /dev/null
@@ -1,14 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# 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/.
-
-DevToolsModules(
-    "content-process-jsprocessactor-startup.js",
-    "frame-helper.js",
-    "process-helper.js",
-    "service-worker-helper.js",
-    "service-worker-jsprocessactor-startup.js",
-    "worker-helper.js",
-)
diff --git a/devtools/server/actors/watcher/target-helpers/process-helper.js b/devtools/server/actors/watcher/target-helpers/process-helper.js
deleted file mode 100644
index e36f0a204c..0000000000
--- a/devtools/server/actors/watcher/target-helpers/process-helper.js
+++ /dev/null
@@ -1,115 +0,0 @@
-/* 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";
-
-/**
- * Return the list of all DOM Processes except the one for the parent process
- *
- * @return Array<nsIDOMProcessParent>
- */
-function getAllContentProcesses() {
-  return ChromeUtils.getAllDOMProcesses().filter(
-    process => process.childID !== 0
-  );
-}
-
-/**
- * Instantiate all Content Process targets in all the DOM Processes.
- *
- * @param {WatcherActor} watcher
- */
-async function createTargets(watcher) {
-  const promises = [];
-  for (const domProcess of getAllContentProcesses()) {
-    const processActor = domProcess.getActor("DevToolsProcess");
-    promises.push(
-      processActor.instantiateTarget({
-        watcherActorID: watcher.actorID,
-        connectionPrefix: watcher.conn.prefix,
-        sessionContext: watcher.sessionContext,
-        sessionData: watcher.sessionData,
-      })
-    );
-  }
-  await Promise.all(promises);
-}
-
-/**
- * @param {WatcherActor} watcher
- * @param {object} options
- * @param {boolean} options.isModeSwitching
- *        true when this is called as the result of a change to the devtools.browsertoolbox.scope pref
- */
-function destroyTargets(watcher, options) {
-  for (const domProcess of getAllContentProcesses()) {
-    const processActor = domProcess.getActor("DevToolsProcess");
-    processActor.destroyTarget({
-      watcherActorID: watcher.actorID,
-      isModeSwitching: options.isModeSwitching,
-    });
-  }
-}
-
-/**
- * Go over all existing content processes in order to communicate about new data entries
- *
- * @param {Object} options
- * @param {WatcherActor} options.watcher
- *        The Watcher Actor providing new data entries
- * @param {string} options.type
- *        The type of data to be added
- * @param {Array<Object>} options.entries
- *        The values to be added to this type of data
- * @param String updateType
- *        "add" will only add the new entries in the existing data set.
- *        "set" will update the data set with the new entries.
- */
-async function addOrSetSessionDataEntry({
-  watcher,
-  type,
-  entries,
-  updateType,
-}) {
-  const promises = [];
-  for (const domProcess of getAllContentProcesses()) {
-    const processActor = domProcess.getActor("DevToolsProcess");
-    promises.push(
-      processActor.addOrSetSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        type,
-        entries,
-        updateType,
-      })
-    );
-  }
-  await Promise.all(promises);
-}
-
-/**
- * Notify all existing content processes that some data entries have been removed
- *
- * See addOrSetSessionDataEntry for argument documentation.
- */
-async function removeSessionDataEntry({ watcher, type, entries }) {
-  const promises = [];
-  for (const domProcess of getAllContentProcesses()) {
-    const processActor = domProcess.getActor("DevToolsProcess");
-    promises.push(
-      processActor.removeSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        type,
-        entries,
-      })
-    );
-  }
-  await Promise.all(promises);
-}
-
-module.exports = {
-  createTargets,
-  destroyTargets,
-  addOrSetSessionDataEntry,
-  removeSessionDataEntry,
-};
diff --git a/devtools/server/actors/watcher/target-helpers/service-worker-helper.js b/devtools/server/actors/watcher/target-helpers/service-worker-helper.js
deleted file mode 100644
index 53fceead17..0000000000
--- a/devtools/server/actors/watcher/target-helpers/service-worker-helper.js
+++ /dev/null
@@ -1,220 +0,0 @@
-/* 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";
-
-const { waitForTick } = require("resource://devtools/shared/DevToolsUtils.js");
-
-const PROCESS_SCRIPT_URL =
-  "resource://devtools/server/actors/watcher/target-helpers/service-worker-jsprocessactor-startup.js";
-
-const PROCESS_ACTOR_NAME = "DevToolsServiceWorker";
-const PROCESS_ACTOR_OPTIONS = {
-  // Ignore the parent process.
-  includeParent: false,
-
-  parent: {
-    esModuleURI:
-      "resource://devtools/server/connectors/process-actor/DevToolsServiceWorkerParent.sys.mjs",
-  },
-
-  child: {
-    esModuleURI:
-      "resource://devtools/server/connectors/process-actor/DevToolsServiceWorkerChild.sys.mjs",
-
-    observers: [
-      // Tried various notification to ensure starting the actor
-      // from webServiceWorker processes... but none of them worked.
-      /*
-      "chrome-event-target-created",
-      "webnavigation-create",
-      "chrome-webnavigation-create",
-      "webnavigation-destroy",
-      "chrome-webnavigation-destroy",
-      "browsing-context-did-set-embedder",
-      "browsing-context-discarded",
-      "ipc:content-initializing",
-      "ipc:content-created",
-      */
-
-      // Fallback on firing a very custom notification from a "process script" (loadProcessScript)
-      "init-devtools-service-worker-actor",
-    ],
-  },
-};
-
-// List of all active watchers
-const gWatchers = new Set();
-
-/**
- * Register the DevToolsServiceWorker JS Process Actor,
- * if we are registering the first watcher actor.
- *
- * @param {Watcher Actor} watcher
- */
-function maybeRegisterProcessActor(watcher) {
-  const sizeBefore = gWatchers.size;
-  gWatchers.add(watcher);
-
-  if (sizeBefore == 0 && gWatchers.size == 1) {
-    ChromeUtils.registerProcessActor(PROCESS_ACTOR_NAME, PROCESS_ACTOR_OPTIONS);
-
-    // For some reason JSProcessActor doesn't work out of the box for `webServiceWorker` content processes.
-    // So manually spawn our JSProcessActor from a process script emitting an observer service notification...
-    // The Process script are correctly executed on all process types during their early startup.
-    Services.ppmm.loadProcessScript(PROCESS_SCRIPT_URL, true);
-  }
-}
-
-/**
- * Unregister the DevToolsServiceWorker JS Process Actor,
- * if we are unregistering the last watcher actor.
- *
- * @param {Watcher Actor} watcher
- */
-function maybeUnregisterProcessActor(watcher) {
-  const sizeBefore = gWatchers.size;
-  gWatchers.delete(watcher);
-
-  if (sizeBefore == 1 && gWatchers.size == 0) {
-    ChromeUtils.unregisterProcessActor(
-      PROCESS_ACTOR_NAME,
-      PROCESS_ACTOR_OPTIONS
-    );
-
-    Services.ppmm.removeDelayedProcessScript(PROCESS_SCRIPT_URL);
-  }
-}
-
-/**
- * Return the list of all DOM Processes except the one for the parent process
- *
- * @return Array<nsIDOMProcessParent>
- */
-function getAllContentProcesses() {
-  return ChromeUtils.getAllDOMProcesses().filter(
-    process => process.childID !== 0
-  );
-}
-
-/**
- * Force creating targets for all existing service workers for a given Watcher Actor.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to watch for new targets.
- */
-async function createTargets(watcher) {
-  maybeRegisterProcessActor(watcher);
-  // Go over all existing content process in order to:
-  // - Force the instantiation of a DevToolsServiceWorkerChild
-  // - Have the DevToolsServiceWorkerChild to spawn the WorkerTargetActors
-
-  const promises = [];
-  for (const process of getAllContentProcesses()) {
-    const promise = process
-      .getActor(PROCESS_ACTOR_NAME)
-      .instantiateServiceWorkerTargets({
-        watcherActorID: watcher.actorID,
-        connectionPrefix: watcher.conn.prefix,
-        sessionContext: watcher.sessionContext,
-        sessionData: watcher.sessionData,
-      });
-    promises.push(promise);
-  }
-
-  // Await for the different queries in order to try to resolve only *after* we received
-  // the already available worker targets.
-  return Promise.all(promises);
-}
-
-/**
- * Force destroying all worker targets which were related to a given watcher.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to stop watching for new targets.
- */
-async function destroyTargets(watcher) {
-  // Go over all existing content processes in order to destroy all targets
-  for (const process of getAllContentProcesses()) {
-    let processActor;
-    try {
-      processActor = process.getActor(PROCESS_ACTOR_NAME);
-    } catch (e) {
-      // Ignore any exception during destroy as we may be closing firefox/devtools/tab
-      // and that can easily lead to many exceptions.
-      continue;
-    }
-
-    processActor.destroyServiceWorkerTargets({
-      watcherActorID: watcher.actorID,
-      sessionContext: watcher.sessionContext,
-    });
-  }
-
-  // browser_dbg-breakpoints-columns.js crashes if we unregister the Process Actor
-  // in the same event loop as we call destroyServiceWorkerTargets.
-  await waitForTick();
-
-  maybeUnregisterProcessActor(watcher);
-}
-
-/**
- * Go over all existing JSProcessActor in order to communicate about new data entries
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to update data entries.
- * @param string type
- *        The type of data to be added
- * @param Array<Object> entries
- *        The values to be added to this type of data
- * @param String updateType
- *        "add" will only add the new entries in the existing data set.
- *        "set" will update the data set with the new entries.
- */
-async function addOrSetSessionDataEntry({
-  watcher,
-  type,
-  entries,
-  updateType,
-}) {
-  maybeRegisterProcessActor(watcher);
-  const promises = [];
-  for (const process of getAllContentProcesses()) {
-    const promise = process
-      .getActor(PROCESS_ACTOR_NAME)
-      .addOrSetSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        sessionContext: watcher.sessionContext,
-        type,
-        entries,
-        updateType,
-      });
-    promises.push(promise);
-  }
-  // Await for the queries in order to try to resolve only *after* the remote code processed the new data
-  return Promise.all(promises);
-}
-
-/**
- * Notify all existing frame targets that some data entries have been removed
- *
- * See addOrSetSessionDataEntry for argument documentation.
- */
-function removeSessionDataEntry({ watcher, type, entries }) {
-  for (const process of getAllContentProcesses()) {
-    process.getActor(PROCESS_ACTOR_NAME).removeSessionDataEntry({
-      watcherActorID: watcher.actorID,
-      sessionContext: watcher.sessionContext,
-      type,
-      entries,
-    });
-  }
-}
-
-module.exports = {
-  createTargets,
-  destroyTargets,
-  addOrSetSessionDataEntry,
-  removeSessionDataEntry,
-};
diff --git a/devtools/server/actors/watcher/target-helpers/service-worker-jsprocessactor-startup.js b/devtools/server/actors/watcher/target-helpers/service-worker-jsprocessactor-startup.js
deleted file mode 100644
index 03f042ad68..0000000000
--- a/devtools/server/actors/watcher/target-helpers/service-worker-jsprocessactor-startup.js
+++ /dev/null
@@ -1,26 +0,0 @@
-/* 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";
-
-const { setTimeout } = ChromeUtils.importESModule(
-  "resource://gre/modules/Timer.sys.mjs"
-);
-
-/*
-   We can't spawn the JSProcessActor right away and have to spin the event loop.
-   Otherwise it isn't registered yet and isn't listening to observer service.
-   Could it be the reason why JSProcessActor aren't spawn via process actor option's child.observers notifications ??
-*/
-setTimeout(function () {
-  /*
-    This notification is registered in DevToolsServiceWorker JS process actor's options's `observers` attribute
-    and will force the JS Process actor to be instantiated in all processes.
-  */
-  Services.obs.notifyObservers(null, "init-devtools-service-worker-actor");
-  /*
-    Instead of using observer service, we could also manually call some method of the actor:
-    ChromeUtils.domProcessChild.getActor("DevToolsServiceWorker").observe(null, "foo");
-  */
-}, 0);
diff --git a/devtools/server/actors/watcher/target-helpers/worker-helper.js b/devtools/server/actors/watcher/target-helpers/worker-helper.js
deleted file mode 100644
index 671d1dc706..0000000000
--- a/devtools/server/actors/watcher/target-helpers/worker-helper.js
+++ /dev/null
@@ -1,137 +0,0 @@
-/* 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";
-
-const DEVTOOLS_WORKER_JS_WINDOW_ACTOR_NAME = "DevToolsWorker";
-
-/**
- * Force creating targets for all existing workers for a given Watcher Actor.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to watch for new targets.
- */
-async function createTargets(watcher) {
-  // Go over all existing BrowsingContext in order to:
-  // - Force the instantiation of a DevToolsWorkerChild
-  // - Have the DevToolsWorkerChild to spawn the WorkerTargetActors
-  const browsingContexts = watcher.getAllBrowsingContexts({
-    acceptSameProcessIframes: true,
-    forceAcceptTopLevelTarget: true,
-  });
-  const promises = [];
-  for (const browsingContext of browsingContexts) {
-    const promise = browsingContext.currentWindowGlobal
-      .getActor(DEVTOOLS_WORKER_JS_WINDOW_ACTOR_NAME)
-      .instantiateWorkerTargets({
-        watcherActorID: watcher.actorID,
-        connectionPrefix: watcher.conn.prefix,
-        sessionContext: watcher.sessionContext,
-        sessionData: watcher.sessionData,
-      });
-    promises.push(promise);
-  }
-
-  // Await for the different queries in order to try to resolve only *after* we received
-  // the already available worker targets.
-  return Promise.all(promises);
-}
-
-/**
- * Force destroying all worker targets which were related to a given watcher.
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to stop watching for new targets.
- */
-async function destroyTargets(watcher) {
-  // Go over all existing BrowsingContext in order to destroy all targets
-  const browsingContexts = watcher.getAllBrowsingContexts({
-    acceptSameProcessIframes: true,
-    forceAcceptTopLevelTarget: true,
-  });
-  for (const browsingContext of browsingContexts) {
-    let windowActor;
-    try {
-      windowActor = browsingContext.currentWindowGlobal.getActor(
-        DEVTOOLS_WORKER_JS_WINDOW_ACTOR_NAME
-      );
-    } catch (e) {
-      continue;
-    }
-
-    windowActor.destroyWorkerTargets({
-      watcherActorID: watcher.actorID,
-      sessionContext: watcher.sessionContext,
-    });
-  }
-}
-
-/**
- * Go over all existing BrowsingContext in order to communicate about new data entries
- *
- * @param WatcherActor watcher
- *        The Watcher Actor requesting to stop watching for new targets.
- * @param string type
- *        The type of data to be added
- * @param Array<Object> entries
- *        The values to be added to this type of data
- * @param String updateType
- *        "add" will only add the new entries in the existing data set.
- *        "set" will update the data set with the new entries.
- */
-async function addOrSetSessionDataEntry({
-  watcher,
-  type,
-  entries,
-  updateType,
-}) {
-  const browsingContexts = watcher.getAllBrowsingContexts({
-    acceptSameProcessIframes: true,
-    forceAcceptTopLevelTarget: true,
-  });
-  const promises = [];
-  for (const browsingContext of browsingContexts) {
-    const promise = browsingContext.currentWindowGlobal
-      .getActor(DEVTOOLS_WORKER_JS_WINDOW_ACTOR_NAME)
-      .addOrSetSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        sessionContext: watcher.sessionContext,
-        type,
-        entries,
-        updateType,
-      });
-    promises.push(promise);
-  }
-  // Await for the queries in order to try to resolve only *after* the remote code processed the new data
-  return Promise.all(promises);
-}
-
-/**
- * Notify all existing frame targets that some data entries have been removed
- *
- * See addOrSetSessionDataEntry for argument documentation.
- */
-function removeSessionDataEntry({ watcher, type, entries }) {
-  const browsingContexts = watcher.getAllBrowsingContexts({
-    acceptSameProcessIframes: true,
-    forceAcceptTopLevelTarget: true,
-  });
-  for (const browsingContext of browsingContexts) {
-    browsingContext.currentWindowGlobal
-      .getActor(DEVTOOLS_WORKER_JS_WINDOW_ACTOR_NAME)
-      .removeSessionDataEntry({
-        watcherActorID: watcher.actorID,
-        sessionContext: watcher.sessionContext,
-        type,
-        entries,
-      });
-  }
-}
-
-module.exports = {
-  createTargets,
-  destroyTargets,
-  addOrSetSessionDataEntry,
-  removeSessionDataEntry,
-};
diff --git a/devtools/server/actors/webconsole/commands/manager.js b/devtools/server/actors/webconsole/commands/manager.js
index 025e197e3b..e96e0a617f 100644
--- a/devtools/server/actors/webconsole/commands/manager.js
+++ b/devtools/server/actors/webconsole/commands/manager.js
@@ -11,13 +11,6 @@ loader.lazyRequireGetter(
   true
 );
 
-loader.lazyRequireGetter(
-  this,
-  ["DOM_MUTATIONS"],
-  "resource://devtools/server/tracer/tracer.jsm",
-  true
-);
-
 loader.lazyGetter(this, "l10n", () => {
   return new Localization(
     [
@@ -27,6 +20,16 @@ loader.lazyGetter(this, "l10n", () => {
     true
   );
 });
+
+const lazy = {};
+ChromeUtils.defineESModuleGetters(
+  lazy,
+  {
+    JSTracer: "resource://devtools/server/tracer/tracer.sys.mjs",
+  },
+  { global: "contextual" }
+);
+
 const USAGE_STRING_MAPPING = {
   block: "webconsole-commands-usage-block",
   trace: "webconsole-commands-usage-trace3",
@@ -888,7 +891,7 @@ WebConsoleCommandsManager.register({
       } else if (typeof args["dom-mutations"] == "string") {
         // Otherwise consider the value as coma seperated list and remove any white space.
         traceDOMMutations = args["dom-mutations"].split(",").map(e => e.trim());
-        const acceptedValues = Object.values(DOM_MUTATIONS);
+        const acceptedValues = Object.values(lazy.JSTracer.DOM_MUTATIONS);
         if (!traceDOMMutations.every(e => acceptedValues.includes(e))) {
           throw new Error(
             `:trace --dom-mutations only accept a list of strings whose values can be: ${acceptedValues}`
author	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-05-15 03:34:50 +0000
committer	Daniel Baumann <daniel.baumann@progress-linux.org>	2024-05-15 03:34:50 +0000
commit	def92d1b8e9d373e2f6f27c366d578d97d8960c6 (patch)
tree	2ef34b9ad8bb9a9220e05d60352558b15f513894 /devtools/server/actors
parent	Adding debian version 125.0.3-1. (diff)
download	firefox-def92d1b8e9d373e2f6f27c366d578d97d8960c6.tar.xz firefox-def92d1b8e9d373e2f6f27c366d578d97d8960c6.zip