diff --git a/dom/base/Attr.h b/dom/base/Attr.h
index 95248a6e0b16..2acc5e9fefec 100644
--- a/dom/base/Attr.h
+++ b/dom/base/Attr.h
@@ -12,7 +12,6 @@
 #define mozilla_dom_Attr_h
 
 #include "mozilla/Attributes.h"
-#include "nsDOMAttributeMap.h"
 #include "nsINode.h"
 #include "nsString.h"
 #include "nsCOMPtr.h"
diff --git a/dom/base/DirectionalityUtils.cpp b/dom/base/DirectionalityUtils.cpp
index 00c11a593dba..39a156ee004a 100644
--- a/dom/base/DirectionalityUtils.cpp
+++ b/dom/base/DirectionalityUtils.cpp
@@ -224,7 +224,6 @@
 namespace mozilla {
 
 using mozilla::dom::Element;
-using mozilla::dom::HTMLSlotElement;
 using mozilla::dom::ShadowRoot;
 
 static nsIContent* GetParentOrHostOrSlot(
diff --git a/dom/base/NodeUbiReporting.h b/dom/base/NodeUbiReporting.h
index 27bfdfa6fc9b..86eb802a7baf 100644
--- a/dom/base/NodeUbiReporting.h
+++ b/dom/base/NodeUbiReporting.h
@@ -7,8 +7,6 @@
 #ifndef dom_NodeUbiReporting_h
 #define dom_NodeUbiReporting_h
 
-#include "Attr.h"
-#include "Document.h"
 #include "nsIContent.h"
 #include "nsIContentInlines.h"
 #include "nsINode.h"
diff --git a/dom/base/ThirdPartyUtil.cpp b/dom/base/ThirdPartyUtil.cpp
index 0185c032a64f..1748c4d21f62 100644
--- a/dom/base/ThirdPartyUtil.cpp
+++ b/dom/base/ThirdPartyUtil.cpp
@@ -18,11 +18,9 @@
 #include "nsReadableUtils.h"
 #include "nsThreadUtils.h"
 #include "mozilla/ClearOnShutdown.h"
-#include "mozilla/dom/Document.h"
 #include "mozilla/Logging.h"
 #include "mozilla/StaticPtr.h"
 #include "mozilla/Unused.h"
-#include "nsGlobalWindowOuter.h"
 #include "nsPIDOMWindow.h"
 
 NS_IMPL_ISUPPORTS(ThirdPartyUtil, mozIThirdPartyUtil)
@@ -94,16 +92,6 @@ nsresult ThirdPartyUtil::IsThirdPartyInternal(const nsCString& aFirstDomain,
   return NS_OK;
 }
 
-nsCString ThirdPartyUtil::GetBaseDomainFromWindow(nsPIDOMWindowOuter* aWindow) {
-  mozilla::dom::Document* doc = aWindow ? aWindow->GetExtantDoc() : nullptr;
-
-  if (!doc) {
-    return EmptyCString();
-  }
-
-  return doc->GetBaseDomain();
-}
-
 NS_IMETHODIMP
 ThirdPartyUtil::GetPrincipalFromWindow(mozIDOMWindowProxy* aWin,
                                        nsIPrincipal** result) {
diff --git a/dom/base/ThirdPartyUtil.h b/dom/base/ThirdPartyUtil.h
index 9710891a3cdb..525e6ccf5a1f 100644
--- a/dom/base/ThirdPartyUtil.h
+++ b/dom/base/ThirdPartyUtil.h
@@ -14,7 +14,6 @@
 #include "mozilla/Attributes.h"
 
 class nsIURI;
-class nsPIDOMWindowOuter;
 
 class ThirdPartyUtil final : public mozIThirdPartyUtil {
  public:
@@ -37,7 +36,15 @@ class ThirdPartyUtil final : public mozIThirdPartyUtil {
   nsresult IsThirdPartyInternal(const nsCString& aFirstDomain,
                                 nsIURI* aSecondURI, bool* aResult);
 
-  nsCString GetBaseDomainFromWindow(nsPIDOMWindowOuter* aWindow);
+  nsCString GetBaseDomainFromWindow(nsPIDOMWindowOuter* aWindow) {
+    mozilla::dom::Document* doc = aWindow ? aWindow->GetExtantDoc() : nullptr;
+
+    if (!doc) {
+      return EmptyCString();
+    }
+
+    return doc->GetBaseDomain();
+  }
 
   RefPtr<nsEffectiveTLDService> mTLDService;
 };
diff --git a/dom/base/nsDOMAttributeMap.h b/dom/base/nsDOMAttributeMap.h
index e852d5cabd9f..8cb73617d12b 100644
--- a/dom/base/nsDOMAttributeMap.h
+++ b/dom/base/nsDOMAttributeMap.h
@@ -12,6 +12,7 @@
 #define nsDOMAttributeMap_h
 
 #include "mozilla/MemoryReporting.h"
+#include "mozilla/dom/Attr.h"
 #include "mozilla/ErrorResult.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsRefPtrHashtable.h"
@@ -19,15 +20,10 @@
 #include "nsWrapperCache.h"
 
 class nsAtom;
-class nsINode;
 
 namespace mozilla {
 namespace dom {
-class Attr;
 class DocGroup;
-class Document;
-class Element;
-class NodeInfo;
 }  // namespace dom
 }  // namespace mozilla
 
diff --git a/dom/base/nsDataDocumentContentPolicy.cpp b/dom/base/nsDataDocumentContentPolicy.cpp
index e9f3739cf3fd..22522649e0bb 100644
--- a/dom/base/nsDataDocumentContentPolicy.cpp
+++ b/dom/base/nsDataDocumentContentPolicy.cpp
@@ -11,7 +11,6 @@
  */
 
 #include "nsContentUtils.h"
-#include "nsContentPolicyUtils.h"
 #include "nsDataDocumentContentPolicy.h"
 #include "nsNetUtil.h"
 #include "nsIProtocolHandler.h"
@@ -41,7 +40,7 @@ nsDataDocumentContentPolicy::ShouldLoad(nsIURI* aContentLocation,
                                         nsILoadInfo* aLoadInfo,
                                         const nsACString& aMimeGuess,
                                         int16_t* aDecision) {
-  auto setBlockingReason = mozilla::MakeScopeExit([&]() {
+  auto setBlockingReason = MakeScopeExit([&]() {
     if (NS_CP_REJECTED(*aDecision)) {
       NS_SetRequestBlockingReason(
           aLoadInfo, nsILoadInfo::BLOCKING_REASON_CONTENT_POLICY_DATA_DOCUMENT);
diff --git a/dom/base/nsGlobalWindowInner.cpp b/dom/base/nsGlobalWindowInner.cpp
index d50eccbede40..e5c6f0e3ac55 100644
--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -17,9 +17,7 @@
 #include "nsHistory.h"
 #include "nsDOMNavigationTiming.h"
 #include "nsIDOMStorageManager.h"
-#include "mozilla/dom/CallbackDebuggerNotification.h"
 #include "mozilla/dom/ContentFrameMessageManager.h"
-#include "mozilla/dom/DebuggerNotification.h"
 #include "mozilla/dom/DocumentInlines.h"
 #include "mozilla/dom/DOMJSProxyHandler.h"
 #include "mozilla/dom/EventTarget.h"
@@ -1375,8 +1373,6 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(nsGlobalWindowInner)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCacheStorage)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mVRDisplays)
 
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDebuggerNotificationManager)
-
   // Traverse stuff from nsPIDOMWindow
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mChromeEventHandler)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParentTarget)
@@ -1475,8 +1471,6 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsGlobalWindowInner)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCacheStorage)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mVRDisplays)
 
-  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDebuggerNotificationManager)
-
   // Unlink stuff from nsPIDOMWindow
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mChromeEventHandler)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mParentTarget)
@@ -3298,9 +3292,6 @@ int32_t nsGlobalWindowInner::RequestAnimationFrame(
     js::NotifyAnimationActivity(GetWrapperPreserveColor());
   }
 
-  DebuggerNotificationDispatch(this,
-                               DebuggerNotificationType::RequestAnimationFrame);
-
   int32_t handle;
   aError = mDoc->ScheduleFrameRequestCallback(aCallback, &handle);
   return handle;
@@ -3312,9 +3303,6 @@ void nsGlobalWindowInner::CancelAnimationFrame(int32_t aHandle,
     return;
   }
 
-  DebuggerNotificationDispatch(this,
-                               DebuggerNotificationType::CancelAnimationFrame);
-
   mDoc->CancelFrameRequestCallback(aHandle);
 }
 
@@ -3745,16 +3733,12 @@ void nsGlobalWindowInner::MozScrollSnap() {
 }
 
 void nsGlobalWindowInner::ClearTimeout(int32_t aHandle) {
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::ClearTimeout);
-
   if (aHandle > 0) {
     mTimeoutManager->ClearTimeout(aHandle, Timeout::Reason::eTimeoutOrInterval);
   }
 }
 
 void nsGlobalWindowInner::ClearInterval(int32_t aHandle) {
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::ClearInterval);
-
   if (aHandle > 0) {
     mTimeoutManager->ClearTimeout(aHandle, Timeout::Reason::eTimeoutOrInterval);
   }
@@ -4022,20 +4006,6 @@ EventListenerManager* nsGlobalWindowInner::GetExistingListenerManager() const {
   return mListenerManager;
 }
 
-mozilla::dom::DebuggerNotificationManager*
-nsGlobalWindowInner::GetOrCreateDebuggerNotificationManager() {
-  if (!mDebuggerNotificationManager) {
-    mDebuggerNotificationManager = new DebuggerNotificationManager(this);
-  }
-
-  return mDebuggerNotificationManager;
-}
-
-mozilla::dom::DebuggerNotificationManager*
-nsGlobalWindowInner::GetExistingDebuggerNotificationManager() {
-  return mDebuggerNotificationManager;
-}
-
 //*****************************************************************************
 // nsGlobalWindowInner::nsPIDOMWindow
 //*****************************************************************************
@@ -5731,15 +5701,10 @@ int32_t nsGlobalWindowInner::SetTimeoutOrInterval(
   }
 
   if (inner != this) {
-    RefPtr<nsGlobalWindowInner> innerRef(inner);
-    return innerRef->SetTimeoutOrInterval(aCx, aFunction, aTimeout, aArguments,
-                                          aIsInterval, aError);
+    return inner->SetTimeoutOrInterval(aCx, aFunction, aTimeout, aArguments,
+                                       aIsInterval, aError);
   }
 
-  DebuggerNotificationDispatch(
-      this, aIsInterval ? DebuggerNotificationType::SetInterval
-                        : DebuggerNotificationType::SetTimeout);
-
   nsCOMPtr<nsIScriptTimeoutHandler> handler =
       NS_CreateJSTimeoutHandler(aCx, this, aFunction, aArguments, aError);
   if (!handler) {
@@ -5764,15 +5729,10 @@ int32_t nsGlobalWindowInner::SetTimeoutOrInterval(JSContext* aCx,
   }
 
   if (inner != this) {
-    RefPtr<nsGlobalWindowInner> innerRef(inner);
-    return innerRef->SetTimeoutOrInterval(aCx, aHandler, aTimeout, aIsInterval,
-                                          aError);
+    return inner->SetTimeoutOrInterval(aCx, aHandler, aTimeout, aIsInterval,
+                                       aError);
   }
 
-  DebuggerNotificationDispatch(
-      this, aIsInterval ? DebuggerNotificationType::SetInterval
-                        : DebuggerNotificationType::SetTimeout);
-
   nsCOMPtr<nsIScriptTimeoutHandler> handler =
       NS_CreateJSTimeoutHandler(aCx, this, aHandler, aError);
   if (!handler) {
@@ -5820,10 +5780,6 @@ bool nsGlobalWindowInner::RunTimeoutHandler(Timeout* aTimeout,
     reason = "setTimeout handler";
   }
 
-  auto timerNotificationType =
-      timeout->mIsInterval ? DebuggerNotificationType::SetIntervalCallback
-                           : DebuggerNotificationType::SetTimeoutCallback;
-
   bool abortIntervalHandler = false;
   nsCOMPtr<nsIScriptTimeoutHandler> handler(
       do_QueryInterface(timeout->mScriptHandler));
@@ -5857,8 +5813,6 @@ bool nsGlobalWindowInner::RunTimeoutHandler(Timeout* aTimeout,
             initiatingScript->AssociateWithScript(script);
           }
 
-          CallbackDebuggerNotificationGuard guard(this, timerNotificationType);
-
           rv = exec.ExecScript();
         }
       }
@@ -5871,13 +5825,7 @@ bool nsGlobalWindowInner::RunTimeoutHandler(Timeout* aTimeout,
       nsCOMPtr<nsISupports> me(static_cast<nsIDOMWindow*>(this));
       ErrorResult rv;
       JS::Rooted<JS::Value> ignoredVal(RootingCx());
-
-      {
-        CallbackDebuggerNotificationGuard guard(this, timerNotificationType);
-
-        callback->Call(me, handler->GetArgs(), &ignoredVal, rv, reason);
-      }
-
+      callback->Call(me, handler->GetArgs(), &ignoredVal, rv, reason);
       if (rv.IsUncatchableException()) {
         abortIntervalHandler = true;
       }
@@ -5888,9 +5836,6 @@ bool nsGlobalWindowInner::RunTimeoutHandler(Timeout* aTimeout,
     nsCOMPtr<nsITimeoutHandler> basicHandler(timeout->mScriptHandler);
     nsCOMPtr<nsISupports> kungFuDeathGrip(static_cast<nsIDOMWindow*>(this));
     mozilla::Unused << kungFuDeathGrip;
-
-    CallbackDebuggerNotificationGuard guard(this, timerNotificationType);
-
     basicHandler->Call();
   }
 
diff --git a/dom/base/nsGlobalWindowInner.h b/dom/base/nsGlobalWindowInner.h
index 7359b2f22fa5..79a582cc66f3 100644
--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -36,7 +36,6 @@
 #include "prclist.h"
 #include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/dom/ChromeMessageBroadcaster.h"
-#include "mozilla/dom/DebuggerNotificationManager.h"
 #include "mozilla/dom/NavigatorBinding.h"
 #include "mozilla/dom/StorageEvent.h"
 #include "mozilla/dom/StorageEventBinding.h"
@@ -285,12 +284,6 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
 
   virtual mozilla::EventListenerManager* GetOrCreateListenerManager() override;
 
-  mozilla::Maybe<mozilla::dom::EventCallbackDebuggerNotificationType>
-  GetDebuggerNotificationType() const override {
-    return mozilla::Some(
-        mozilla::dom::EventCallbackDebuggerNotificationType::Global);
-  }
-
   bool ComputeDefaultWantsUntrusted(mozilla::ErrorResult& aRv) final;
 
   virtual nsPIDOMWindowOuter* GetOwnerGlobalForBindingsInternal() override;
@@ -324,12 +317,6 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
   virtual bool IsFrozen() const override;
   void SyncStateFromParentWindow();
 
-  mozilla::dom::DebuggerNotificationManager*
-  GetOrCreateDebuggerNotificationManager() override;
-
-  mozilla::dom::DebuggerNotificationManager*
-  GetExistingDebuggerNotificationManager() override;
-
   mozilla::Maybe<mozilla::dom::ClientInfo> GetClientInfo() const override;
   mozilla::Maybe<mozilla::dom::ClientState> GetClientState() const;
   mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor> GetController()
@@ -694,35 +681,23 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
                       const mozilla::dom::WindowPostMessageOptions& aOptions,
                       nsIPrincipal& aSubjectPrincipal,
                       mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetTimeout(JSContext* aCx, mozilla::dom::Function& aFunction,
                      int32_t aTimeout,
                      const mozilla::dom::Sequence<JS::Value>& aArguments,
                      mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetTimeout(JSContext* aCx, const nsAString& aHandler,
                      int32_t aTimeout,
                      const mozilla::dom::Sequence<JS::Value>& /* unused */,
                      mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   void ClearTimeout(int32_t aHandle);
-
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetInterval(JSContext* aCx, mozilla::dom::Function& aFunction,
                       const int32_t aTimeout,
                       const mozilla::dom::Sequence<JS::Value>& aArguments,
                       mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetInterval(JSContext* aCx, const nsAString& aHandler,
                       const int32_t aTimeout,
                       const mozilla::dom::Sequence<JS::Value>& /* unused */,
                       mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   void ClearInterval(int32_t aHandle);
   void GetOrigin(nsAString& aOrigin);
   void Atob(const nsAString& aAsciiBase64String, nsAString& aBinaryData,
@@ -819,12 +794,8 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
   void SetOuterHeight(JSContext* aCx, JS::Handle<JS::Value> aValue,
                       mozilla::dom::CallerType aCallerType,
                       mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   int32_t RequestAnimationFrame(mozilla::dom::FrameRequestCallback& aCallback,
                                 mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   void CancelAnimationFrame(int32_t aHandle, mozilla::ErrorResult& aError);
 
   uint32_t RequestIdleCallback(JSContext* aCx,
@@ -1088,13 +1059,10 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
  public:
   // Timeout Functions
   // |interval| is in milliseconds.
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetTimeoutOrInterval(
       JSContext* aCx, mozilla::dom::Function& aFunction, int32_t aTimeout,
       const mozilla::dom::Sequence<JS::Value>& aArguments, bool aIsInterval,
       mozilla::ErrorResult& aError);
-
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetTimeoutOrInterval(JSContext* aCx, const nsAString& aHandler,
                                int32_t aTimeout, bool aIsInterval,
                                mozilla::ErrorResult& aError);
@@ -1349,9 +1317,6 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
   nsCOMPtr<nsIPrincipal> mDocumentStoragePrincipal;
   nsCOMPtr<nsIContentSecurityPolicy> mDocumentCsp;
 
-  RefPtr<mozilla::dom::DebuggerNotificationManager>
-      mDebuggerNotificationManager;
-
   // mBrowserChild is only ever populated in the content process.
   nsCOMPtr<nsIBrowserChild> mBrowserChild;
 
diff --git a/dom/base/nsIGlobalObject.h b/dom/base/nsIGlobalObject.h
index ccaf46003d2c..aca2c3297f9b 100644
--- a/dom/base/nsIGlobalObject.h
+++ b/dom/base/nsIGlobalObject.h
@@ -35,7 +35,6 @@ namespace mozilla {
 class DOMEventTargetHelper;
 namespace dom {
 class VoidFunction;
-class DebuggerNotificationManager;
 class ServiceWorker;
 class ServiceWorkerRegistration;
 class ServiceWorkerRegistrationDescriptor;
@@ -132,16 +131,6 @@ class nsIGlobalObject : public nsISupports,
 
   virtual bool IsInSyncOperation() { return false; }
 
-  virtual mozilla::dom::DebuggerNotificationManager*
-  GetOrCreateDebuggerNotificationManager() {
-    return nullptr;
-  }
-
-  virtual mozilla::dom::DebuggerNotificationManager*
-  GetExistingDebuggerNotificationManager() {
-    return nullptr;
-  }
-
   virtual mozilla::Maybe<mozilla::dom::ClientInfo> GetClientInfo() const;
 
   virtual mozilla::Maybe<mozilla::dom::ServiceWorkerDescriptor> GetController()
diff --git a/dom/base/nsINode.h b/dom/base/nsINode.h
index 26d9ca2af9eb..b4ff63f51509 100644
--- a/dom/base/nsINode.h
+++ b/dom/base/nsINode.h
@@ -940,12 +940,6 @@ class nsINode : public mozilla::dom::EventTarget {
       const override;
   virtual mozilla::EventListenerManager* GetOrCreateListenerManager() override;
 
-  mozilla::Maybe<mozilla::dom::EventCallbackDebuggerNotificationType>
-  GetDebuggerNotificationType() const override {
-    return mozilla::Some(
-        mozilla::dom::EventCallbackDebuggerNotificationType::Node);
-  }
-
   bool ComputeDefaultWantsUntrusted(mozilla::ErrorResult& aRv) final;
 
   virtual bool IsApzAware() const override;
diff --git a/dom/bindings/Bindings.conf b/dom/bindings/Bindings.conf
index e5bdd80974fb..4e46bbe4824d 100644
--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -201,13 +201,6 @@ DOMInterfaces = {
     'implicitJSContext': ['define'],
 },
 
-'DebuggerNotification': {
-    'concrete': True,
-},
-'CallbackDebuggerNotification': {
-    'concrete': True,
-},
-
 'DedicatedWorkerGlobalScope': {
     'headerFile': 'mozilla/dom/WorkerScope.h',
 },
diff --git a/dom/chrome-webidl/DebuggerNotification.webidl b/dom/chrome-webidl/DebuggerNotification.webidl
deleted file mode 100644
index 7487e4688df6..000000000000
--- a/dom/chrome-webidl/DebuggerNotification.webidl
+++ /dev/null
@@ -1,57 +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/. */
-
-enum DebuggerNotificationType {
-  // DebuggerNotification
-  "setTimeout",
-  "clearTimeout",
-  "setInterval",
-  "clearInterval",
-  "requestAnimationFrame",
-  "cancelAnimationFrame",
-
-  // CallbackDebuggerNotification
-  "setTimeoutCallback",
-  "setIntervalCallback",
-  "requestAnimationFrameCallback",
-
-  // EventCallbackDebuggerNotification
-  "domEvent",
-};
-
-[ChromeOnly]
-interface DebuggerNotification {
-  readonly attribute DebuggerNotificationType type;
-
-  // The global object that has triggered the notification.
-  readonly attribute object global;
-};
-
-// For DOM events, we send notifications just before, and just after the
-// event handler has been dispatched so that listeners
-enum CallbackDebuggerNotificationPhase {
-  "pre",
-  "post",
-};
-
-// A base notification type for notifications that are dispatched as pairs with
-// a before and after notification.
-[ChromeOnly]
-interface CallbackDebuggerNotification : DebuggerNotification {
-  readonly attribute CallbackDebuggerNotificationPhase phase;
-};
-
-enum EventCallbackDebuggerNotificationType {
-  "global",
-  "node",
-  "xhr",
-  "worker",
-};
-
-// A notification that about the engine calling a DOM event handler.
-[ChromeOnly]
-interface EventCallbackDebuggerNotification : CallbackDebuggerNotification {
-  readonly attribute Event event;
-  readonly attribute EventCallbackDebuggerNotificationType targetType;
-};
diff --git a/dom/chrome-webidl/DebuggerNotificationObserver.webidl b/dom/chrome-webidl/DebuggerNotificationObserver.webidl
deleted file mode 100644
index 5494d95bfd5b..000000000000
--- a/dom/chrome-webidl/DebuggerNotificationObserver.webidl
+++ /dev/null
@@ -1,28 +0,0 @@
-/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* 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/.
- */
-
-callback DebuggerNotificationCallback = void (DebuggerNotification n);
-
-[ChromeOnly, Constructor, Exposed=(Window, Worker)]
-interface DebuggerNotificationObserver {
-  // Throws if the object is not a browser global or does not support
-  // debugger notifications.
-  // Returns false if already connected to this global.
-  [Throws]
-  boolean connect(object global);
-
-  // Throws if the object is not a browser global or does not support
-  // debugger notifications.
-  // Returns false if not connected to this global.
-  [Throws]
-  boolean disconnect(object global);
-
-  // Returns false if listener already added.
-  boolean addListener(DebuggerNotificationCallback handler);
-
-  // Returns false if listener was not found.
-  boolean removeListener(DebuggerNotificationCallback handler);
-};
diff --git a/dom/chrome-webidl/moz.build b/dom/chrome-webidl/moz.build
index 2200a1a7e9db..de0e1a302d0a 100644
--- a/dom/chrome-webidl/moz.build
+++ b/dom/chrome-webidl/moz.build
@@ -35,8 +35,6 @@ PREPROCESSED_WEBIDL_FILES = [
 WEBIDL_FILES = [
     'BrowsingContext.webidl',
     'ChannelWrapper.webidl',
-    'DebuggerNotification.webidl',
-    'DebuggerNotificationObserver.webidl',
     'DocumentL10n.webidl',
     'DominatorTree.webidl',
     'DOMLocalization.webidl',
diff --git a/dom/debugger/CallbackDebuggerNotification.cpp b/dom/debugger/CallbackDebuggerNotification.cpp
deleted file mode 100644
index 71c6ea0f6038..000000000000
--- a/dom/debugger/CallbackDebuggerNotification.cpp
+++ /dev/null
@@ -1,35 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#include "CallbackDebuggerNotification.h"
-
-namespace mozilla {
-namespace dom {
-
-NS_IMPL_CYCLE_COLLECTION_INHERITED(CallbackDebuggerNotification,
-                                   DebuggerNotification)
-
-NS_IMPL_ADDREF_INHERITED(CallbackDebuggerNotification, DebuggerNotification)
-NS_IMPL_RELEASE_INHERITED(CallbackDebuggerNotification, DebuggerNotification)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CallbackDebuggerNotification)
-NS_INTERFACE_MAP_END_INHERITING(DebuggerNotification)
-
-JSObject* CallbackDebuggerNotification::WrapObject(
-    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
-  return CallbackDebuggerNotification_Binding::Wrap(aCx, this, aGivenProto);
-}
-
-already_AddRefed<DebuggerNotification> CallbackDebuggerNotification::CloneInto(
-    nsIGlobalObject* aNewOwner) const {
-  RefPtr<CallbackDebuggerNotification> notification(
-      new CallbackDebuggerNotification(mDebuggeeGlobal, mType, mPhase,
-                                       aNewOwner));
-  return notification.forget();
-}
-
-}  // namespace dom
-}  // namespace mozilla
diff --git a/dom/debugger/CallbackDebuggerNotification.h b/dom/debugger/CallbackDebuggerNotification.h
deleted file mode 100644
index deab8142d537..000000000000
--- a/dom/debugger/CallbackDebuggerNotification.h
+++ /dev/null
@@ -1,79 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#ifndef mozilla_dom_CallbackDebuggerNotification_h
-#define mozilla_dom_CallbackDebuggerNotification_h
-
-#include "DebuggerNotification.h"
-#include "DebuggerNotificationManager.h"
-
-namespace mozilla {
-namespace dom {
-
-class CallbackDebuggerNotification : public DebuggerNotification {
- public:
-  NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CallbackDebuggerNotification,
-                                           DebuggerNotification)
-
-  CallbackDebuggerNotification(nsIGlobalObject* aDebuggeeGlobal,
-                               DebuggerNotificationType aType,
-                               CallbackDebuggerNotificationPhase aPhase,
-                               nsIGlobalObject* aOwnerGlobal = nullptr)
-      : DebuggerNotification(aDebuggeeGlobal, aType, aOwnerGlobal),
-        mPhase(aPhase) {}
-
-  // nsWrapperCache
-  virtual JSObject* WrapObject(JSContext* aCx,
-                               JS::Handle<JSObject*> aGivenProto) override;
-
-  already_AddRefed<DebuggerNotification> CloneInto(
-      nsIGlobalObject* aNewOwner) const override;
-
-  CallbackDebuggerNotificationPhase Phase() const { return mPhase; }
-
- protected:
-  ~CallbackDebuggerNotification() = default;
-
-  CallbackDebuggerNotificationPhase mPhase;
-};
-
-class MOZ_RAII CallbackDebuggerNotificationGuard final {
- public:
-  MOZ_CAN_RUN_SCRIPT CallbackDebuggerNotificationGuard(
-      nsIGlobalObject* aDebuggeeGlobal, DebuggerNotificationType aType)
-      : mDebuggeeGlobal(aDebuggeeGlobal), mType(aType) {
-    Dispatch(CallbackDebuggerNotificationPhase::Pre);
-  }
-  CallbackDebuggerNotificationGuard(const CallbackDebuggerNotificationGuard&) =
-      delete;
-  CallbackDebuggerNotificationGuard(CallbackDebuggerNotificationGuard&&) =
-      delete;
-  CallbackDebuggerNotificationGuard& operator=(
-      const CallbackDebuggerNotificationGuard&) = delete;
-  CallbackDebuggerNotificationGuard& operator=(
-      CallbackDebuggerNotificationGuard&&) = delete;
-
-  MOZ_CAN_RUN_SCRIPT ~CallbackDebuggerNotificationGuard() {
-    Dispatch(CallbackDebuggerNotificationPhase::Post);
-  }
-
- private:
-  MOZ_CAN_RUN_SCRIPT void Dispatch(CallbackDebuggerNotificationPhase aPhase) {
-    auto manager = DebuggerNotificationManager::ForDispatch(mDebuggeeGlobal);
-    if (MOZ_UNLIKELY(manager)) {
-      manager->Dispatch<CallbackDebuggerNotification>(mType, aPhase);
-    }
-  }
-
-  nsIGlobalObject* mDebuggeeGlobal;
-  DebuggerNotificationType mType;
-};
-
-}  // namespace dom
-}  // namespace mozilla
-
-#endif  // mozilla_dom_CallbackDebuggerNotification_h
diff --git a/dom/debugger/DebuggerNotification.cpp b/dom/debugger/DebuggerNotification.cpp
deleted file mode 100644
index f1de648cf220..000000000000
--- a/dom/debugger/DebuggerNotification.cpp
+++ /dev/null
@@ -1,38 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#include "DebuggerNotification.h"
-
-#include "DebuggerNotificationManager.h"
-
-namespace mozilla {
-namespace dom {
-
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DebuggerNotification, mDebuggeeGlobal,
-                                      mOwnerGlobal)
-
-NS_IMPL_CYCLE_COLLECTING_ADDREF(DebuggerNotification)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(DebuggerNotification)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DebuggerNotification)
-  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
-NS_INTERFACE_MAP_END
-
-JSObject* DebuggerNotification::WrapObject(JSContext* aCx,
-                                           JS::Handle<JSObject*> aGivenProto) {
-  return DebuggerNotification_Binding::Wrap(aCx, this, aGivenProto);
-}
-
-already_AddRefed<DebuggerNotification> DebuggerNotification::CloneInto(
-    nsIGlobalObject* aNewOwner) const {
-  RefPtr<DebuggerNotification> notification(
-      new DebuggerNotification(mDebuggeeGlobal, mType, aNewOwner));
-  return notification.forget();
-}
-
-}  // namespace dom
-}  // namespace mozilla
diff --git a/dom/debugger/DebuggerNotification.h b/dom/debugger/DebuggerNotification.h
deleted file mode 100644
index c4f34b460bcd..000000000000
--- a/dom/debugger/DebuggerNotification.h
+++ /dev/null
@@ -1,72 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#ifndef mozilla_dom_DebuggerNotification_h
-#define mozilla_dom_DebuggerNotification_h
-
-#include "DebuggerNotificationManager.h"
-#include "mozilla/dom/DebuggerNotificationBinding.h"
-#include "nsIGlobalObject.h"
-#include "nsISupports.h"
-#include "nsWrapperCache.h"
-
-namespace mozilla {
-namespace dom {
-
-class DebuggerNotification : public nsISupports, public nsWrapperCache {
- public:
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DebuggerNotification)
-
-  DebuggerNotification(nsIGlobalObject* aDebuggeeGlobal,
-                       DebuggerNotificationType aType,
-                       nsIGlobalObject* aOwnerGlobal = nullptr)
-      : mType(aType),
-        mDebuggeeGlobal(aDebuggeeGlobal),
-        mOwnerGlobal(aOwnerGlobal){};
-
-  nsIGlobalObject* GetParentObject() const {
-    MOZ_ASSERT(mOwnerGlobal,
-               "Notification must be cloned into an observer global before "
-               "being wrapped");
-    return mOwnerGlobal;
-  }
-
-  DebuggerNotificationType Type() const { return mType; }
-
-  void GetGlobal(JSContext* aCx, JS::MutableHandle<JSObject*> aResult) {
-    aResult.set(mDebuggeeGlobal->GetGlobalJSObject());
-  }
-
-  virtual already_AddRefed<DebuggerNotification> CloneInto(
-      nsIGlobalObject* aNewOwner) const;
-
-  // nsWrapperCache
-  virtual JSObject* WrapObject(JSContext* aCx,
-                               JS::Handle<JSObject*> aGivenProto) override;
-
- protected:
-  virtual ~DebuggerNotification() = default;
-
-  DebuggerNotificationType mType;
-  nsCOMPtr<nsIGlobalObject> mDebuggeeGlobal;
-
- private:
-  nsCOMPtr<nsIGlobalObject> mOwnerGlobal;
-};
-
-MOZ_CAN_RUN_SCRIPT inline void DebuggerNotificationDispatch(
-    nsIGlobalObject* aDebuggeeGlobal, DebuggerNotificationType aType) {
-  auto manager = DebuggerNotificationManager::ForDispatch(aDebuggeeGlobal);
-  if (MOZ_UNLIKELY(manager)) {
-    manager->Dispatch<DebuggerNotification>(aType);
-  }
-}
-
-}  // namespace dom
-}  // namespace mozilla
-
-#endif  // mozilla_dom_DebuggerNotification_h
diff --git a/dom/debugger/DebuggerNotificationManager.cpp b/dom/debugger/DebuggerNotificationManager.cpp
deleted file mode 100644
index 4e13838f1450..000000000000
--- a/dom/debugger/DebuggerNotificationManager.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#include "DebuggerNotificationManager.h"
-
-#include "mozilla/ScopeExit.h"
-#include "nsIGlobalObject.h"
-
-namespace mozilla {
-namespace dom {
-
-NS_IMPL_CYCLE_COLLECTION(DebuggerNotificationManager, mDebuggeeGlobal,
-                         mNotificationObservers)
-
-NS_IMPL_CYCLE_COLLECTING_ADDREF(DebuggerNotificationManager)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(DebuggerNotificationManager)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DebuggerNotificationManager)
-  NS_INTERFACE_MAP_ENTRY(nsISupports)
-NS_INTERFACE_MAP_END
-
-NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(DebuggerNotificationManager)
-NS_IMPL_CYCLE_COLLECTION_TRACE_END
-
-bool DebuggerNotificationManager::Attach(
-    DebuggerNotificationObserver* aObserver) {
-  RefPtr<DebuggerNotificationObserver> ptr(aObserver);
-
-  if (mNotificationObservers.Contains(ptr)) {
-    return false;
-  }
-
-  mNotificationObservers.AppendElement(ptr);
-  return true;
-}
-bool DebuggerNotificationManager::Detach(
-    DebuggerNotificationObserver* aObserver) {
-  RefPtr<DebuggerNotificationObserver> ptr(aObserver);
-
-  return mNotificationObservers.RemoveElement(ptr);
-}
-
-bool DebuggerNotificationManager::HasListeners() {
-  nsTObserverArray<RefPtr<DebuggerNotificationObserver>>::ForwardIterator iter(
-      mNotificationObservers);
-
-  while (iter.HasMore()) {
-    RefPtr<DebuggerNotificationObserver> observer(iter.GetNext());
-    if (observer->HasListeners()) {
-      return true;
-    }
-  }
-
-  return false;
-}
-
-void DebuggerNotificationManager::NotifyListeners(
-    DebuggerNotification* aNotification) {
-  nsTObserverArray<RefPtr<DebuggerNotificationObserver>>::ForwardIterator iter(
-      mNotificationObservers);
-
-  while (iter.HasMore()) {
-    RefPtr<DebuggerNotificationObserver> observer(iter.GetNext());
-    observer->NotifyListeners(aNotification);
-  }
-}
-
-}  // namespace dom
-}  // namespace mozilla
diff --git a/dom/debugger/DebuggerNotificationManager.h b/dom/debugger/DebuggerNotificationManager.h
deleted file mode 100644
index bed9dce85106..000000000000
--- a/dom/debugger/DebuggerNotificationManager.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#ifndef mozilla_dom_DebuggerNotificationManager_h
-#define mozilla_dom_DebuggerNotificationManager_h
-
-#include "DebuggerNotificationObserver.h"
-#include "nsCycleCollectionParticipant.h"
-#include "nsIGlobalObject.h"
-#include "nsISupports.h"
-#include "nsTObserverArray.h"
-
-namespace mozilla {
-namespace dom {
-
-class DebuggerNotificationManager final : public nsISupports {
- public:
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DebuggerNotificationManager)
-
-  static RefPtr<DebuggerNotificationManager> ForDispatch(
-      nsIGlobalObject* aDebuggeeGlobal) {
-    if (MOZ_UNLIKELY(!aDebuggeeGlobal)) {
-      return nullptr;
-    }
-    auto managerPtr = aDebuggeeGlobal->GetExistingDebuggerNotificationManager();
-    if (MOZ_LIKELY(!managerPtr) || !managerPtr->HasListeners()) {
-      return nullptr;
-    }
-
-    return managerPtr;
-  }
-
-  explicit DebuggerNotificationManager(nsIGlobalObject* aDebuggeeGlobal)
-      : mDebuggeeGlobal(aDebuggeeGlobal), mNotificationObservers() {}
-
-  bool Attach(DebuggerNotificationObserver* aObserver);
-  bool Detach(DebuggerNotificationObserver* aObserver);
-
-  bool HasListeners();
-
-  template <typename T, typename... Args>
-  MOZ_CAN_RUN_SCRIPT void Dispatch(Args... aArgs) {
-    RefPtr<DebuggerNotification> notification(new T(mDebuggeeGlobal, aArgs...));
-    NotifyListeners(notification);
-  }
-
- private:
-  ~DebuggerNotificationManager() = default;
-
-  MOZ_CAN_RUN_SCRIPT void NotifyListeners(DebuggerNotification* aNotification);
-
-  nsCOMPtr<nsIGlobalObject> mDebuggeeGlobal;
-  nsTObserverArray<RefPtr<DebuggerNotificationObserver>> mNotificationObservers;
-};
-
-}  // namespace dom
-}  // namespace mozilla
-
-#endif  // mozilla_dom_DebuggerNotificationManager_h
diff --git a/dom/debugger/DebuggerNotificationObserver.cpp b/dom/debugger/DebuggerNotificationObserver.cpp
deleted file mode 100644
index 75bd4a91cf2f..000000000000
--- a/dom/debugger/DebuggerNotificationObserver.cpp
+++ /dev/null
@@ -1,152 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#include "DebuggerNotificationObserver.h"
-
-#include "DebuggerNotification.h"
-#include "nsIGlobalObject.h"
-#include "WrapperFactory.h"
-
-namespace mozilla {
-namespace dom {
-
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DebuggerNotificationObserver,
-                                      mOwnerGlobal, mEventListenerCallbacks)
-
-NS_IMPL_CYCLE_COLLECTING_ADDREF(DebuggerNotificationObserver)
-NS_IMPL_CYCLE_COLLECTING_RELEASE(DebuggerNotificationObserver)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DebuggerNotificationObserver)
-  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
-NS_INTERFACE_MAP_END
-
-/* static */ already_AddRefed<DebuggerNotificationObserver>
-DebuggerNotificationObserver::Constructor(GlobalObject& aGlobal,
-                                          ErrorResult& aRv) {
-  nsCOMPtr<nsIGlobalObject> globalInterface(
-      do_QueryInterface(aGlobal.GetAsSupports()));
-  if (NS_WARN_IF(!globalInterface)) {
-    aRv.Throw(NS_ERROR_FAILURE);
-    return nullptr;
-  }
-
-  RefPtr<DebuggerNotificationObserver> observer(
-      new DebuggerNotificationObserver(globalInterface));
-  return observer.forget();
-}
-
-DebuggerNotificationObserver::DebuggerNotificationObserver(
-    nsIGlobalObject* aOwnerGlobal)
-    : mEventListenerCallbacks(), mOwnerGlobal(aOwnerGlobal) {}
-
-JSObject* DebuggerNotificationObserver::WrapObject(
-    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
-  return DebuggerNotificationObserver_Binding::Wrap(aCx, this, aGivenProto);
-}
-
-static already_AddRefed<DebuggerNotificationManager> GetManager(
-    JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal) {
-  // The debuggee global here is likely a debugger-compartment cross-compartment
-  // wrapper for the debuggee global object, so we need to unwrap it to get
-  // the real debuggee-compartment global object.
-  JS::Rooted<JSObject*> debuggeeGlobalRooted(
-      aCx, js::UncheckedUnwrap(aDebuggeeGlobal, false));
-
-  if (!debuggeeGlobalRooted) {
-    return nullptr;
-  }
-
-  nsCOMPtr<nsIGlobalObject> debuggeeGlobalObject(
-      xpc::NativeGlobal(debuggeeGlobalRooted));
-  if (!debuggeeGlobalObject) {
-    return nullptr;
-  }
-
-  RefPtr<DebuggerNotificationManager> manager(
-      debuggeeGlobalObject->GetOrCreateDebuggerNotificationManager());
-  return manager.forget();
-}
-
-bool DebuggerNotificationObserver::Connect(
-    JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal, ErrorResult& aRv) {
-  RefPtr<DebuggerNotificationManager> manager(GetManager(aCx, aDebuggeeGlobal));
-
-  if (!manager) {
-    aRv.Throw(NS_ERROR_FAILURE);
-    return false;
-  }
-
-  return manager->Attach(this);
-}
-
-bool DebuggerNotificationObserver::Disconnect(
-    JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal, ErrorResult& aRv) {
-  RefPtr<DebuggerNotificationManager> manager(GetManager(aCx, aDebuggeeGlobal));
-
-  if (!manager) {
-    aRv.Throw(NS_ERROR_FAILURE);
-    return false;
-  }
-
-  return manager->Detach(this);
-}
-
-bool DebuggerNotificationObserver::AddListener(
-    DebuggerNotificationCallback& aHandlerFn) {
-  nsTObserverArray<RefPtr<DebuggerNotificationCallback>>::ForwardIterator iter(
-      mEventListenerCallbacks);
-  while (iter.HasMore()) {
-    if (*iter.GetNext().get() == aHandlerFn) {
-      return false;
-    }
-  }
-
-  RefPtr<DebuggerNotificationCallback> handlerFn(&aHandlerFn);
-  mEventListenerCallbacks.AppendElement(handlerFn);
-  return true;
-}
-
-bool DebuggerNotificationObserver::RemoveListener(
-    DebuggerNotificationCallback& aHandlerFn) {
-  nsTObserverArray<RefPtr<DebuggerNotificationCallback>>::ForwardIterator iter(
-      mEventListenerCallbacks);
-  for (uint32_t i = 0; iter.HasMore(); i++) {
-    if (*iter.GetNext().get() == aHandlerFn) {
-      mEventListenerCallbacks.RemoveElementAt(i);
-      return true;
-    }
-  }
-
-  return false;
-}
-
-bool DebuggerNotificationObserver::HasListeners() {
-  return !mEventListenerCallbacks.IsEmpty();
-}
-
-void DebuggerNotificationObserver::NotifyListeners(
-    DebuggerNotification* aNotification) {
-  if (!HasListeners()) {
-    return;
-  }
-
-  // Since we want the notification objects to live in the same compartment
-  // as the observer, we create a new instance of the notification before
-  // an observer dispatches the event listeners.
-  RefPtr<DebuggerNotification> debuggerNotification(
-      aNotification->CloneInto(mOwnerGlobal));
-
-  nsTObserverArray<RefPtr<DebuggerNotificationCallback>>::ForwardIterator iter(
-      mEventListenerCallbacks);
-
-  while (iter.HasMore()) {
-    RefPtr<DebuggerNotificationCallback> cb(iter.GetNext());
-    cb->Call(*debuggerNotification);
-  }
-}
-
-}  // namespace dom
-}  // namespace mozilla
diff --git a/dom/debugger/DebuggerNotificationObserver.h b/dom/debugger/DebuggerNotificationObserver.h
deleted file mode 100644
index 80ffcb084c7f..000000000000
--- a/dom/debugger/DebuggerNotificationObserver.h
+++ /dev/null
@@ -1,62 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#ifndef mozilla_dom_DebuggerNotificationObserver_h
-#define mozilla_dom_DebuggerNotificationObserver_h
-
-#include "DebuggerNotificationManager.h"
-#include "mozilla/dom/DebuggerNotificationObserverBinding.h"
-#include "mozilla/RefPtr.h"
-#include "nsTObserverArray.h"
-#include "nsWrapperCache.h"
-
-class nsIGlobalObject;
-
-namespace mozilla {
-namespace dom {
-
-class DebuggerNotification;
-
-class DebuggerNotificationObserver final : public nsISupports,
-                                           public nsWrapperCache {
- public:
-  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(DebuggerNotificationObserver)
-
-  static already_AddRefed<DebuggerNotificationObserver> Constructor(
-      GlobalObject& aGlobal, ErrorResult& aRv);
-
-  nsIGlobalObject* GetParentObject() const { return mOwnerGlobal; }
-
-  // nsWrapperCache
-  virtual JSObject* WrapObject(JSContext* aCx,
-                               JS::Handle<JSObject*> aGivenProto) override;
-
-  bool Connect(JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal,
-               ErrorResult& aRv);
-  bool Disconnect(JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal,
-                  ErrorResult& aRv);
-
-  bool AddListener(DebuggerNotificationCallback& aHandlerFn);
-  bool RemoveListener(DebuggerNotificationCallback& aHandlerFn);
-
-  bool HasListeners();
-
-  MOZ_CAN_RUN_SCRIPT void NotifyListeners(DebuggerNotification* aNotification);
-
- private:
-  explicit DebuggerNotificationObserver(nsIGlobalObject* aOwnerGlobal);
-  ~DebuggerNotificationObserver() = default;
-
-  nsTObserverArray<RefPtr<DebuggerNotificationCallback>>
-      mEventListenerCallbacks;
-  nsCOMPtr<nsIGlobalObject> mOwnerGlobal;
-};
-
-}  // namespace dom
-}  // namespace mozilla
-
-#endif  // mozilla_dom_DebuggerNotificationObserver_h
diff --git a/dom/debugger/EventCallbackDebuggerNotification.cpp b/dom/debugger/EventCallbackDebuggerNotification.cpp
deleted file mode 100644
index 14d3879f8c02..000000000000
--- a/dom/debugger/EventCallbackDebuggerNotification.cpp
+++ /dev/null
@@ -1,65 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#include "EventCallbackDebuggerNotification.h"
-
-#include "DebuggerNotificationManager.h"
-#include "mozilla/dom/EventTarget.h"
-#include "mozilla/dom/Worker.h"
-#include "mozilla/dom/XMLHttpRequestEventTarget.h"
-#include "nsIGlobalObject.h"
-#include "nsINode.h"
-#include "nsQueryObject.h"
-
-namespace mozilla {
-namespace dom {
-
-NS_IMPL_CYCLE_COLLECTION_INHERITED(EventCallbackDebuggerNotification,
-                                   CallbackDebuggerNotification, mEvent)
-
-NS_IMPL_ADDREF_INHERITED(EventCallbackDebuggerNotification,
-                         CallbackDebuggerNotification)
-NS_IMPL_RELEASE_INHERITED(EventCallbackDebuggerNotification,
-                          CallbackDebuggerNotification)
-
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(EventCallbackDebuggerNotification)
-NS_INTERFACE_MAP_END_INHERITING(CallbackDebuggerNotification)
-
-JSObject* EventCallbackDebuggerNotification::WrapObject(
-    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
-  return EventCallbackDebuggerNotification_Binding::Wrap(aCx, this,
-                                                         aGivenProto);
-}
-
-already_AddRefed<DebuggerNotification>
-EventCallbackDebuggerNotification::CloneInto(nsIGlobalObject* aNewOwner) const {
-  RefPtr<EventCallbackDebuggerNotification> notification(
-      new EventCallbackDebuggerNotification(mDebuggeeGlobal, mType, mEvent,
-                                            mTargetType, mPhase, aNewOwner));
-  return notification.forget();
-}
-
-void EventCallbackDebuggerNotificationGuard::DispatchToManager(
-    const RefPtr<DebuggerNotificationManager>& aManager,
-    CallbackDebuggerNotificationPhase aPhase) {
-  if (!mEventTarget) {
-    MOZ_ASSERT(false, "target should exist");
-    return;
-  }
-
-  Maybe<EventCallbackDebuggerNotificationType> notificationType(
-      mEventTarget->GetDebuggerNotificationType());
-
-  if (notificationType) {
-    aManager->Dispatch<EventCallbackDebuggerNotification>(
-        DebuggerNotificationType::DomEvent,
-        // The DOM event will always be live during event dispatch.
-        MOZ_KnownLive(mEvent), *notificationType, aPhase);
-  }
-}
-
-}  // namespace dom
-}  // namespace mozilla
diff --git a/dom/debugger/EventCallbackDebuggerNotification.h b/dom/debugger/EventCallbackDebuggerNotification.h
deleted file mode 100644
index 34b0fa955417..000000000000
--- a/dom/debugger/EventCallbackDebuggerNotification.h
+++ /dev/null
@@ -1,95 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set ts=8 sts=2 et sw=2 tw=80: */
-/* 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/. */
-
-#ifndef mozilla_dom_EventCallbackDebuggerNotification_h
-#define mozilla_dom_EventCallbackDebuggerNotification_h
-
-#include "CallbackDebuggerNotification.h"
-#include "DebuggerNotificationManager.h"
-#include "mozilla/dom/Event.h"
-#include "mozilla/RefPtr.h"
-
-namespace mozilla {
-namespace dom {
-
-class EventCallbackDebuggerNotification : public CallbackDebuggerNotification {
- public:
-  NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(EventCallbackDebuggerNotification,
-                                           CallbackDebuggerNotification)
-
-  EventCallbackDebuggerNotification(
-      nsIGlobalObject* debuggeeGlobal, DebuggerNotificationType t, Event* event,
-      EventCallbackDebuggerNotificationType targetType,
-      CallbackDebuggerNotificationPhase phase,
-      nsIGlobalObject* ownerGlobal = nullptr)
-      : CallbackDebuggerNotification(debuggeeGlobal, t, phase, ownerGlobal),
-        mEvent(event),
-        mTargetType(targetType) {}
-
-  // nsWrapperCache
-  virtual JSObject* WrapObject(JSContext* aCx,
-                               JS::Handle<JSObject*> aGivenProto) override;
-
-  already_AddRefed<DebuggerNotification> CloneInto(
-      nsIGlobalObject* newOwner) const override;
-
-  mozilla::dom::Event* Event() const { return mEvent; }
-  EventCallbackDebuggerNotificationType TargetType() const {
-    return mTargetType;
-  }
-
- private:
-  ~EventCallbackDebuggerNotification() = default;
-
-  RefPtr<mozilla::dom::Event> mEvent;
-  EventCallbackDebuggerNotificationType mTargetType;
-};
-
-class MOZ_RAII EventCallbackDebuggerNotificationGuard final {
- public:
-  MOZ_CAN_RUN_SCRIPT explicit EventCallbackDebuggerNotificationGuard(
-      mozilla::dom::EventTarget* aEventTarget, mozilla::dom::Event* aEvent)
-      : mDebuggeeGlobal(aEventTarget ? aEventTarget->GetOwnerGlobal()
-                                     : nullptr),
-        mEventTarget(aEventTarget),
-        mEvent(aEvent) {
-    Dispatch(CallbackDebuggerNotificationPhase::Pre);
-  }
-  EventCallbackDebuggerNotificationGuard(
-      const EventCallbackDebuggerNotificationGuard&) = delete;
-  EventCallbackDebuggerNotificationGuard(
-      EventCallbackDebuggerNotificationGuard&&) = delete;
-  EventCallbackDebuggerNotificationGuard& operator=(
-      const EventCallbackDebuggerNotificationGuard&) = delete;
-  EventCallbackDebuggerNotificationGuard& operator=(
-      EventCallbackDebuggerNotificationGuard&&) = delete;
-
-  MOZ_CAN_RUN_SCRIPT ~EventCallbackDebuggerNotificationGuard() {
-    Dispatch(CallbackDebuggerNotificationPhase::Post);
-  }
-
- private:
-  MOZ_CAN_RUN_SCRIPT void Dispatch(CallbackDebuggerNotificationPhase aPhase) {
-    auto manager = DebuggerNotificationManager::ForDispatch(mDebuggeeGlobal);
-    if (MOZ_UNLIKELY(manager)) {
-      DispatchToManager(manager, aPhase);
-    }
-  }
-
-  MOZ_CAN_RUN_SCRIPT void DispatchToManager(
-      const RefPtr<DebuggerNotificationManager>& aManager,
-      CallbackDebuggerNotificationPhase aPhase);
-
-  nsIGlobalObject* mDebuggeeGlobal;
-  mozilla::dom::EventTarget* mEventTarget;
-  mozilla::dom::Event* mEvent;
-};
-
-}  // namespace dom
-}  // namespace mozilla
-
-#endif  // mozilla_dom_EventCallbackDebuggerNotification_h
diff --git a/dom/debugger/moz.build b/dom/debugger/moz.build
deleted file mode 100644
index 0ebcd3c33deb..000000000000
--- a/dom/debugger/moz.build
+++ /dev/null
@@ -1,26 +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/.
-
-with Files("**"):
-    BUG_COMPONENT = ("DevTools", "Debugger")
-
-EXPORTS.mozilla.dom += [
-    'CallbackDebuggerNotification.h',
-    'DebuggerNotification.h',
-    'DebuggerNotificationManager.h',
-    'DebuggerNotificationObserver.h',
-    'EventCallbackDebuggerNotification.h',
-]
-
-UNIFIED_SOURCES += [
-    'CallbackDebuggerNotification.cpp',
-    'DebuggerNotification.cpp',
-    'DebuggerNotificationManager.cpp',
-    'DebuggerNotificationObserver.cpp',
-    'EventCallbackDebuggerNotification.cpp',
-]
-
-FINAL_LIBRARY = 'xul'
\ No newline at end of file
diff --git a/dom/events/EventListenerManager.cpp b/dom/events/EventListenerManager.cpp
index 440a0c4969a9..de5063ab8df8 100644
--- a/dom/events/EventListenerManager.cpp
+++ b/dom/events/EventListenerManager.cpp
@@ -20,7 +20,6 @@
 #include "mozilla/Preferences.h"
 #include "mozilla/PresShell.h"
 #include "mozilla/dom/BindingUtils.h"
-#include "mozilla/dom/EventCallbackDebuggerNotification.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/Event.h"
 #include "mozilla/dom/EventTargetBinding.h"
@@ -1015,7 +1014,6 @@ nsresult EventListenerManager::HandleEventSubType(Listener* aListener,
   }
 
   if (NS_SUCCEEDED(result)) {
-    EventCallbackDebuggerNotificationGuard dbgGuard(aCurrentTarget, aDOMEvent);
     nsAutoMicroTask mt;
 
     // Event::currentTarget is set in EventDispatcher.
diff --git a/dom/events/EventTarget.h b/dom/events/EventTarget.h
index e03ceb18ccab..7e122369cd6b 100644
--- a/dom/events/EventTarget.h
+++ b/dom/events/EventTarget.h
@@ -8,7 +8,6 @@
 #define mozilla_dom_EventTarget_h_
 
 #include "mozilla/dom/BindingDeclarations.h"
-#include "mozilla/dom/DebuggerNotificationBinding.h"
 #include "mozilla/dom/Nullable.h"
 #include "nsISupports.h"
 #include "nsWrapperCache.h"
@@ -196,11 +195,6 @@ class EventTarget : public nsISupports, public nsWrapperCache {
    */
   virtual EventListenerManager* GetExistingListenerManager() const = 0;
 
-  virtual Maybe<EventCallbackDebuggerNotificationType>
-  GetDebuggerNotificationType() const {
-    return Nothing();
-  }
-
   // Called from AsyncEventDispatcher to notify it is running.
   virtual void AsyncEventRunning(AsyncEventDispatcher* aEvent) {}
 
diff --git a/dom/moz.build b/dom/moz.build
index 34b3e86d7417..ffd9742f73a7 100644
--- a/dom/moz.build
+++ b/dom/moz.build
@@ -44,7 +44,6 @@ DIRS += [
     'commandhandler',
     'credentialmanagement',
     'crypto',
-    'debugger',
     'encoding',
     'events',
     'fetch',
diff --git a/dom/workers/RegisterBindings.cpp b/dom/workers/RegisterBindings.cpp
index 3cdce4ba1157..f0e0f0a7fb97 100644
--- a/dom/workers/RegisterBindings.cpp
+++ b/dom/workers/RegisterBindings.cpp
@@ -9,7 +9,6 @@
 #include "RuntimeService.h"
 
 #include "jsapi.h"
-#include "mozilla/dom/DebuggerNotificationObserverBinding.h"
 #include "mozilla/dom/RegisterWorkerBindings.h"
 #include "mozilla/dom/RegisterWorkerDebuggerBindings.h"
 #include "mozilla/OSFileConstants.h"
@@ -53,10 +52,6 @@ bool WorkerPrivate::RegisterDebuggerBindings(JSContext* aCx,
     return false;
   }
 
-  if (!DebuggerNotificationObserver_Binding::GetConstructorObject(aCx)) {
-    return false;
-  }
-
   if (!JS_DefineDebuggerObject(aCx, aGlobal)) {
     return false;
   }
diff --git a/dom/workers/Worker.h b/dom/workers/Worker.h
index 5bd804efb7fe..ed0b9ed6e235 100644
--- a/dom/workers/Worker.h
+++ b/dom/workers/Worker.h
@@ -8,7 +8,6 @@
 #define mozilla_dom_Worker_h
 
 #include "mozilla/Attributes.h"
-#include "mozilla/dom/DebuggerNotificationBinding.h"
 #include "mozilla/DOMEventTargetHelper.h"
 #include "mozilla/RefPtr.h"
 #include "mozilla/WeakPtr.h"
@@ -39,11 +38,6 @@ class Worker : public DOMEventTargetHelper, public SupportsWeakPtr<Worker> {
   JSObject* WrapObject(JSContext* aCx,
                        JS::Handle<JSObject*> aGivenProto) override;
 
-  Maybe<EventCallbackDebuggerNotificationType> GetDebuggerNotificationType()
-      const override {
-    return Some(EventCallbackDebuggerNotificationType::Worker);
-  }
-
   void PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
                    const Sequence<JSObject*>& aTransferable, ErrorResult& aRv);
 
diff --git a/dom/workers/WorkerPrivate.cpp b/dom/workers/WorkerPrivate.cpp
index 219c7e21a911..bc07c3e98dd3 100644
--- a/dom/workers/WorkerPrivate.cpp
+++ b/dom/workers/WorkerPrivate.cpp
@@ -17,7 +17,6 @@
 #include "mozilla/ScopeExit.h"
 #include "mozilla/StaticPrefs.h"
 #include "mozilla/dom/BlobURLProtocolHandler.h"
-#include "mozilla/dom/CallbackDebuggerNotification.h"
 #include "mozilla/dom/ClientManager.h"
 #include "mozilla/dom/ClientSource.h"
 #include "mozilla/dom/ClientState.h"
@@ -4310,11 +4309,6 @@ bool WorkerPrivate::RunExpiredTimeouts(JSContext* aCx) {
       reason = "setTimeout handler";
     }
 
-    auto timerNotificationType =
-        info->mIsInterval ? DebuggerNotificationType::SetIntervalCallback
-                          : DebuggerNotificationType::SetTimeoutCallback;
-
-    RefPtr<WorkerGlobalScope> scope = GlobalScope();
     RefPtr<Function> callback = info->mHandler->GetCallback();
     if (!callback) {
       nsAutoMicroTask mt;
@@ -4334,9 +4328,6 @@ bool WorkerPrivate::RunExpiredTimeouts(JSContext* aCx) {
       JS::Rooted<JS::Value> unused(aes.cx());
 
       JS::SourceText<char16_t> srcBuf;
-
-      CallbackDebuggerNotificationGuard guard(scope, timerNotificationType);
-
       if (!srcBuf.init(aes.cx(), script.BeginReading(), script.Length(),
                        JS::SourceOwnership::Borrowed) ||
           !JS::Evaluate(aes.cx(), options, srcBuf, &unused)) {
@@ -4348,13 +4339,8 @@ bool WorkerPrivate::RunExpiredTimeouts(JSContext* aCx) {
     } else {
       ErrorResult rv;
       JS::Rooted<JS::Value> ignoredVal(aCx);
-
-      {
-        CallbackDebuggerNotificationGuard guard(scope, timerNotificationType);
-
-        callback->Call(scope, info->mHandler->GetArgs(), &ignoredVal, rv,
-                       reason);
-      }
+      RefPtr<WorkerGlobalScope> scope = GlobalScope();
+      callback->Call(scope, info->mHandler->GetArgs(), &ignoredVal, rv, reason);
       if (rv.IsUncatchableException()) {
         rv.SuppressException();
         retval = false;
diff --git a/dom/workers/WorkerScope.cpp b/dom/workers/WorkerScope.cpp
index 5e805c1e4838..26b016df697a 100644
--- a/dom/workers/WorkerScope.cpp
+++ b/dom/workers/WorkerScope.cpp
@@ -13,7 +13,6 @@
 #include "mozilla/dom/Clients.h"
 #include "mozilla/dom/ClientState.h"
 #include "mozilla/dom/Console.h"
-#include "mozilla/dom/DebuggerNotification.h"
 #include "mozilla/dom/DedicatedWorkerGlobalScopeBinding.h"
 #include "mozilla/dom/Fetch.h"
 #include "mozilla/dom/FunctionBinding.h"
@@ -104,7 +103,6 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(WorkerGlobalScope,
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mNavigator)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mIndexedDB)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCacheStorage)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDebuggerNotificationManager)
   tmp->TraverseHostObjectURIs(cb);
   tmp->mWorkerPrivate->TraverseTimeouts(cb);
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
@@ -119,7 +117,6 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(WorkerGlobalScope,
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mNavigator)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mIndexedDB)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mCacheStorage)
-  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDebuggerNotificationManager)
   tmp->UnlinkHostObjectURIs();
   tmp->mWorkerPrivate->UnlinkTimeouts();
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
@@ -259,8 +256,6 @@ int32_t WorkerGlobalScope::SetTimeout(JSContext* aCx, Function& aHandler,
                                       ErrorResult& aRv) {
   mWorkerPrivate->AssertIsOnWorkerThread();
 
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::SetTimeout);
-
   nsCOMPtr<nsIScriptTimeoutHandler> handler =
       NS_CreateJSTimeoutHandler(aCx, mWorkerPrivate, aHandler, aArguments, aRv);
   if (!handler) {
@@ -276,8 +271,6 @@ int32_t WorkerGlobalScope::SetTimeout(JSContext* aCx, const nsAString& aHandler,
                                       ErrorResult& aRv) {
   mWorkerPrivate->AssertIsOnWorkerThread();
 
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::SetTimeout);
-
   nsCOMPtr<nsIScriptTimeoutHandler> handler =
       NS_CreateJSTimeoutHandler(aCx, mWorkerPrivate, aHandler, aRv);
   if (!handler) {
@@ -289,9 +282,6 @@ int32_t WorkerGlobalScope::SetTimeout(JSContext* aCx, const nsAString& aHandler,
 
 void WorkerGlobalScope::ClearTimeout(int32_t aHandle) {
   mWorkerPrivate->AssertIsOnWorkerThread();
-
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::ClearTimeout);
-
   mWorkerPrivate->ClearTimeout(aHandle);
 }
 
@@ -301,8 +291,6 @@ int32_t WorkerGlobalScope::SetInterval(JSContext* aCx, Function& aHandler,
                                        ErrorResult& aRv) {
   mWorkerPrivate->AssertIsOnWorkerThread();
 
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::SetInterval);
-
   nsCOMPtr<nsIScriptTimeoutHandler> handler =
       NS_CreateJSTimeoutHandler(aCx, mWorkerPrivate, aHandler, aArguments, aRv);
   if (NS_WARN_IF(aRv.Failed())) {
@@ -319,8 +307,6 @@ int32_t WorkerGlobalScope::SetInterval(JSContext* aCx,
                                        ErrorResult& aRv) {
   mWorkerPrivate->AssertIsOnWorkerThread();
 
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::SetInterval);
-
   Sequence<JS::Value> dummy;
 
   nsCOMPtr<nsIScriptTimeoutHandler> handler =
@@ -334,9 +320,6 @@ int32_t WorkerGlobalScope::SetInterval(JSContext* aCx,
 
 void WorkerGlobalScope::ClearInterval(int32_t aHandle) {
   mWorkerPrivate->AssertIsOnWorkerThread();
-
-  DebuggerNotificationDispatch(this, DebuggerNotificationType::ClearInterval);
-
   mWorkerPrivate->ClearTimeout(aHandle);
 }
 
@@ -477,20 +460,6 @@ AbstractThread* WorkerGlobalScope::AbstractMainThreadFor(
   MOZ_CRASH("AbstractMainThreadFor not supported for workers.");
 }
 
-mozilla::dom::DebuggerNotificationManager*
-WorkerGlobalScope::GetOrCreateDebuggerNotificationManager() {
-  if (!mDebuggerNotificationManager) {
-    mDebuggerNotificationManager = new DebuggerNotificationManager(this);
-  }
-
-  return mDebuggerNotificationManager;
-}
-
-mozilla::dom::DebuggerNotificationManager*
-WorkerGlobalScope::GetExistingDebuggerNotificationManager() {
-  return mDebuggerNotificationManager;
-}
-
 Maybe<ClientInfo> WorkerGlobalScope::GetClientInfo() const {
   return mWorkerPrivate->GetClientInfo();
 }
diff --git a/dom/workers/WorkerScope.h b/dom/workers/WorkerScope.h
index 6c244344cb5d..0a178ede4fbf 100644
--- a/dom/workers/WorkerScope.h
+++ b/dom/workers/WorkerScope.h
@@ -10,7 +10,6 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/WorkerCommon.h"
 #include "mozilla/DOMEventTargetHelper.h"
-#include "mozilla/dom/DebuggerNotificationManager.h"
 #include "mozilla/dom/Headers.h"
 #include "mozilla/dom/RequestBinding.h"
 #include "nsWeakReference.h"
@@ -61,8 +60,6 @@ class WorkerGlobalScope : public DOMEventTargetHelper,
   RefPtr<IDBFactory> mIndexedDB;
   RefPtr<cache::CacheStorage> mCacheStorage;
   nsCOMPtr<nsISerialEventTarget> mSerialEventTarget;
-  RefPtr<mozilla::dom::DebuggerNotificationManager>
-      mDebuggerNotificationManager;
 
   uint32_t mWindowInteractionsAllowed;
 
@@ -110,25 +107,19 @@ class WorkerGlobalScope : public DOMEventTargetHelper,
   void ImportScripts(JSContext* aCx, const Sequence<nsString>& aScriptURLs,
                      ErrorResult& aRv);
 
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetTimeout(JSContext* aCx, Function& aHandler, const int32_t aTimeout,
                      const Sequence<JS::Value>& aArguments, ErrorResult& aRv);
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetTimeout(JSContext* aCx, const nsAString& aHandler,
                      const int32_t aTimeout,
                      const Sequence<JS::Value>& /* unused */, ErrorResult& aRv);
-  MOZ_CAN_RUN_SCRIPT
   void ClearTimeout(int32_t aHandle);
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetInterval(JSContext* aCx, Function& aHandler,
                       const int32_t aTimeout,
                       const Sequence<JS::Value>& aArguments, ErrorResult& aRv);
-  MOZ_CAN_RUN_SCRIPT
   int32_t SetInterval(JSContext* aCx, const nsAString& aHandler,
                       const int32_t aTimeout,
                       const Sequence<JS::Value>& /* unused */,
                       ErrorResult& aRv);
-  MOZ_CAN_RUN_SCRIPT
   void ClearInterval(int32_t aHandle);
 
   void GetOrigin(nsAString& aOrigin) const;
@@ -192,18 +183,6 @@ class WorkerGlobalScope : public DOMEventTargetHelper,
 
   AbstractThread* AbstractMainThreadFor(TaskCategory aCategory) override;
 
-  mozilla::dom::DebuggerNotificationManager*
-  GetOrCreateDebuggerNotificationManager() override;
-
-  mozilla::dom::DebuggerNotificationManager*
-  GetExistingDebuggerNotificationManager() override;
-
-  mozilla::Maybe<mozilla::dom::EventCallbackDebuggerNotificationType>
-  GetDebuggerNotificationType() const override {
-    return mozilla::Some(
-        mozilla::dom::EventCallbackDebuggerNotificationType::Global);
-  }
-
   Maybe<ClientInfo> GetClientInfo() const override;
 
   Maybe<ClientState> GetClientState() const;
diff --git a/dom/xhr/XMLHttpRequestEventTarget.h b/dom/xhr/XMLHttpRequestEventTarget.h
index fd4289610a7e..1e81c7fcd723 100644
--- a/dom/xhr/XMLHttpRequestEventTarget.h
+++ b/dom/xhr/XMLHttpRequestEventTarget.h
@@ -26,11 +26,6 @@ class XMLHttpRequestEventTarget : public DOMEventTargetHelper {
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(XMLHttpRequestEventTarget,
                                            DOMEventTargetHelper)
 
-  mozilla::Maybe<EventCallbackDebuggerNotificationType>
-  GetDebuggerNotificationType() const override {
-    return mozilla::Some(EventCallbackDebuggerNotificationType::Xhr);
-  }
-
   IMPL_EVENT_HANDLER(loadstart)
   IMPL_EVENT_HANDLER(progress)
   IMPL_EVENT_HANDLER(abort)
diff --git a/layout/base/nsRefreshDriver.cpp b/layout/base/nsRefreshDriver.cpp
index 8b45963555ce..7eed0b35aebc 100644
--- a/layout/base/nsRefreshDriver.cpp
+++ b/layout/base/nsRefreshDriver.cpp
@@ -52,7 +52,6 @@
 #include "nsViewManager.h"
 #include "GeckoProfiler.h"
 #include "nsNPAPIPluginInstance.h"
-#include "mozilla/dom/CallbackDebuggerNotification.h"
 #include "mozilla/dom/Event.h"
 #include "mozilla/dom/Performance.h"
 #include "mozilla/dom/Selection.h"
@@ -1696,12 +1695,6 @@ void nsRefreshDriver::RunFrameRequestCallbacks(TimeStamp aNowTime) {
                 callback.mHandle)) {
           continue;
         }
-
-        nsCOMPtr<nsIGlobalObject> global(innerWindow ? innerWindow->AsGlobal()
-                                                     : nullptr);
-        CallbackDebuggerNotificationGuard guard(
-            global, DebuggerNotificationType::RequestAnimationFrameCallback);
-
         // MOZ_KnownLive is OK, because the stack array frameRequestCallbacks
         // keeps callback alive and the mCallback strong reference can't be
         // mutated by the call.