Bug 1673931 - Remove unused includes from Timeout.h.

Differential Revision: https://phabricator.services.mozilla.com/D96541

Depends on D96540

dom/base/Timeout.h

@@ -10,17 +10,12 @@
 #include "mozilla/dom/PopupBlocker.h"
 #include "mozilla/dom/TimeoutHandler.h"
 #include "mozilla/LinkedList.h"
+#include "mozilla/ProfileChunkedBuffer.h"
 #include "mozilla/TimeStamp.h"
-#include "nsCOMPtr.h"
 #include "nsGlobalWindowInner.h"
 #include "nsCycleCollectionParticipant.h"
-#include "GeckoProfiler.h"
 #include "nsDataHashtable.h"
 
-class nsIEventTarget;
-class nsIPrincipal;
-class nsIEventTarget;
-
 namespace mozilla {
 namespace dom {