--- a/dom/xhr/XMLHttpRequestMainThread.cpp
+++ b/dom/xhr/XMLHttpRequestMainThread.cpp
@@ -8,16 +8,17 @@
 
 #include <algorithm>
 #ifndef XP_WIN
 #include <unistd.h>
 #endif
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/CheckedInt.h"
 #include "mozilla/dom/BlobSet.h"
+#include "mozilla/dom/DocGroup.h"
 #include "mozilla/dom/File.h"
 #include "mozilla/dom/FetchUtil.h"
 #include "mozilla/dom/FormData.h"
 #include "mozilla/dom/MutableBlobStorage.h"
 #include "mozilla/dom/XMLDocument.h"
 #include "mozilla/dom/URLSearchParams.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventListenerManager.h"
@@ -3144,16 +3145,25 @@ XMLHttpRequestMainThread::SetTimeout(uin
 
   mTimeoutMilliseconds = aTimeout;
   if (mRequestSentTime) {
     StartTimeoutTimer();
   }
 }
 
 void
+XMLHttpRequestMainThread::SetTimerEventTarget(nsITimer* aTimer)
+{
+  if (nsCOMPtr<nsIGlobalObject> global = GetOwnerGlobal()) {
+    nsCOMPtr<nsIEventTarget> target = global->EventTargetFor(TaskCategory::Other);
+    aTimer->SetTarget(target);
+  }
+}
+
+void
 XMLHttpRequestMainThread::StartTimeoutTimer()
 {
   MOZ_ASSERT(mRequestSentTime,
              "StartTimeoutTimer mustn't be called before the request was sent!");
   if (mState == State::done) {
     // do nothing!
     return;
   }
@@ -3163,16 +3173,17 @@ XMLHttpRequestMainThread::StartTimeoutTi
   }
 
   if (!mTimeoutMilliseconds) {
     return;
   }
 
   if (!mTimeoutTimer) {
     mTimeoutTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+    SetTimerEventTarget(mTimeoutTimer);
   }
   uint32_t elapsed =
     (uint32_t)((PR_Now() - mRequestSentTime) / PR_USEC_PER_MSEC);
   mTimeoutTimer->InitWithCallback(
     this,
     mTimeoutMilliseconds > elapsed ? mTimeoutMilliseconds - elapsed : 0,
     nsITimer::TYPE_ONE_SHOT
   );
@@ -3638,16 +3649,17 @@ XMLHttpRequestMainThread::StopProgressEv
   }
 }
 
 void
 XMLHttpRequestMainThread::StartProgressEventTimer()
 {
   if (!mProgressNotifier) {
     mProgressNotifier = do_CreateInstance(NS_TIMER_CONTRACTID);
+    SetTimerEventTarget(mProgressNotifier);
   }
   if (mProgressNotifier) {
     mProgressTimerIsActive = true;
     mProgressNotifier->Cancel();
     mProgressNotifier->InitWithCallback(this, NS_PROGRESS_EVENT_INTERVAL,
                                         nsITimer::TYPE_ONE_SHOT);
   }
 }
@@ -3664,16 +3676,17 @@ XMLHttpRequestMainThread::MaybeStartSync
 
   // If we are in a beforeunload or a unload event, we must force a timeout.
   TimeDuration diff = (TimeStamp::NowLoRes() - doc->GetPageUnloadingEventTimeStamp());
   if (diff.ToMilliseconds() > MAX_SYNC_TIMEOUT_WHEN_UNLOADING) {
     return eErrorOrExpired;
   }
 
   mSyncTimeoutTimer = do_CreateInstance(NS_TIMER_CONTRACTID);
+  SetTimerEventTarget(mSyncTimeoutTimer);
   if (!mSyncTimeoutTimer) {
     return eErrorOrExpired;
   }
 
   uint32_t timeout = MAX_SYNC_TIMEOUT_WHEN_UNLOADING - diff.ToMilliseconds();
   nsresult rv = mSyncTimeoutTimer->InitWithCallback(this, timeout,
                                                     nsITimer::TYPE_ONE_SHOT);
   return NS_FAILED(rv) ? eErrorOrExpired : eTimerStarted;
@@ -3800,16 +3813,29 @@ XMLHttpRequestMainThread::BlobStoreCompl
   mLoadTotal = mResponseBlob->GetSize(rv);
   if (NS_WARN_IF(rv.Failed())) {
     rv.SuppressException();
   }
 
   ChangeStateToDone();
 }
 
+nsresult
+XMLHttpRequestMainThread::GetName(nsACString& aName)
+{
+  aName.AssignLiteral("XMLHttpRequest");
+  return NS_OK;
+}
+
+nsresult
+XMLHttpRequestMainThread::SetName(const char* aName)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
 // nsXMLHttpRequestXPCOMifier implementation
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsXMLHttpRequestXPCOMifier)
   NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
   NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
   NS_INTERFACE_MAP_ENTRY(nsIChannelEventSink)
   NS_INTERFACE_MAP_ENTRY(nsIAsyncVerifyRedirectCallback)
   NS_INTERFACE_MAP_ENTRY(nsIProgressEventSink)
   NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)

--- a/dom/xhr/XMLHttpRequestMainThread.h
+++ b/dom/xhr/XMLHttpRequestMainThread.h
@@ -159,16 +159,17 @@ class XMLHttpRequestMainThread final : p
                                        public nsIJSXMLHttpRequest,
                                        public nsIStreamListener,
                                        public nsIChannelEventSink,
                                        public nsIProgressEventSink,
                                        public nsIInterfaceRequestor,
                                        public nsSupportsWeakReference,
                                        public nsITimerCallback,
                                        public nsISizeOfEventTarget,
+                                       public nsINamed,
                                        public MutableBlobStorageCallback
 {
   friend class nsXHRParseEndListener;
   friend class nsXMLHttpRequestXPCOMifier;
 
 public:
   enum class ProgressEventType : uint8_t {
     loadstart,
@@ -225,16 +226,19 @@ public:
   NS_DECL_NSIPROGRESSEVENTSINK
 
   // nsIInterfaceRequestor
   NS_DECL_NSIINTERFACEREQUESTOR
 
   // nsITimerCallback
   NS_DECL_NSITIMERCALLBACK
 
+  // nsINamed
+  NS_DECL_NSINAMED
+
   // nsISizeOfEventTarget
   virtual size_t
     SizeOfEventTargetIncludingThis(MallocSizeOf aMallocSizeOf) const override;
 
   NS_REALLY_FORWARD_NSIDOMEVENTTARGET(XMLHttpRequestEventTarget)
 
   // states
   virtual uint16_t ReadyState() const override;
@@ -588,16 +592,18 @@ protected:
 
   void StartProgressEventTimer();
   void StopProgressEventTimer();
 
   void MaybeCreateBlobStorage();
 
   nsresult OnRedirectVerifyCallback(nsresult result);
 
+  void SetTimerEventTarget(nsITimer* aTimer);
+
   already_AddRefed<nsXMLHttpRequestXPCOMifier> EnsureXPCOMifier();
 
   nsCOMPtr<nsISupports> mContext;
   nsCOMPtr<nsIPrincipal> mPrincipal;
   nsCOMPtr<nsIChannel> mChannel;
   nsCString mRequestMethod;
   nsCOMPtr<nsIURI> mRequestURL;
   nsCOMPtr<nsIDocument> mResponseXML;