From 201e447fd0225d17b7be1f68c41486c0560dc6d1 Mon Sep 17 00:00:00 2001
From: Dave Townsend <dtownsend@oxymoronical.com>
Date: Tue, 31 Oct 2023 15:10:43 +0000
Subject: [PATCH] Bug 1855427: The DOMLinkRemoved chrome event is not used
 anywhere. r=emilio

The event isn't dispatched correctly for DOM manipulations anymore. It is
dispatched when swapping docshells but we don't actually use this event anywhere
except tests so we might as well just remove it entirely.

Differential Revision: https://phabricator.services.mozilla.com/D192333
---
 docshell/test/chrome/bug113934_window.xhtml | 11 +----------
 dom/base/Document.cpp                       | 13 -------------
 dom/html/HTMLLinkElement.cpp                |  6 ------
 dom/html/HTMLLinkElement.h                  |  1 -
 4 files changed, 1 insertion(+), 30 deletions(-)

diff --git a/docshell/test/chrome/bug113934_window.xhtml b/docshell/test/chrome/bug113934_window.xhtml
index 794b8b28363f..c5b676b6b8e0 100644
--- a/docshell/test/chrome/bug113934_window.xhtml
+++ b/docshell/test/chrome/bug113934_window.xhtml
@@ -85,7 +85,6 @@
       // which are a result of swapping the docshells.
       var DOMLinkListener = {
         _afterFirst: false,
-        _removedDispatched: false,
         _addedDispatched: false,
         async handleEvent(aEvent) {
           if (!this._afterFirst) {
@@ -134,16 +133,10 @@
             is(this._addedDispatched, false);
             this._addedDispatched = true;
           }
-          else {
-            is(this._removedDispatched, false);
-            this._removedDispatched = true;
-          }
 
-          if (this._addedDispatched && this._removedDispatched) {
+          if (this._addedDispatched) {
             $("f1").removeEventListener("DOMLinkAdded", this);
-            $("f1").removeEventListener("DOMLinkRemoved", this);
             $("f3").removeEventListener("DOMLinkAdded", this);
-            $("f3").removeEventListener("DOMLinkRemoved", this);
             window.close();
             SimpleTest.finish();
           }
@@ -151,9 +144,7 @@
       };
 
       $("f1").addEventListener("DOMLinkAdded", DOMLinkListener);
-      $("f1").addEventListener("DOMLinkRemoved", DOMLinkListener);
       $("f3").addEventListener("DOMLinkAdded", DOMLinkListener);
-      $("f3").addEventListener("DOMLinkRemoved", DOMLinkListener);
 
       var linkElement = $("f1").contentDocument.createElement("link");
       linkElement.setAttribute("rel", "alternate");
diff --git a/dom/base/Document.cpp b/dom/base/Document.cpp
index 7af91579e3d2..20073e552558 100644
--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@@ -11827,19 +11827,6 @@ void Document::OnPageHide(bool aPersisted, EventTarget* aDispatchStartTarget,
       inFrameLoaderSwap ==
       (mDocumentContainer && mDocumentContainer->InFrameSwap()));
 
-  // Send out notifications that our <link> elements are detached,
-  // but only if this is not a full unload.
-  Element* root = GetRootElement();
-  if (aPersisted && root) {
-    RefPtr<nsContentList> links =
-        NS_GetContentList(root, kNameSpaceID_XHTML, u"link"_ns);
-
-    uint32_t linkCount = links->Length(true);
-    for (uint32_t i = 0; i < linkCount; ++i) {
-      static_cast<HTMLLinkElement*>(links->Item(i, false))->LinkRemoved();
-    }
-  }
-
   if (mAnimationController) {
     mAnimationController->OnPageHide();
   }
diff --git a/dom/html/HTMLLinkElement.cpp b/dom/html/HTMLLinkElement.cpp
index f78e24453b80..9d5dc0bca952 100644
--- a/dom/html/HTMLLinkElement.cpp
+++ b/dom/html/HTMLLinkElement.cpp
@@ -108,10 +108,6 @@ void HTMLLinkElement::LinkAdded() {
   CreateAndDispatchEvent(u"DOMLinkAdded"_ns);
 }
 
-void HTMLLinkElement::LinkRemoved() {
-  CreateAndDispatchEvent(u"DOMLinkRemoved"_ns);
-}
-
 void HTMLLinkElement::UnbindFromTree(bool aNullParent) {
   CancelDNSPrefetch(*this);
   CancelPrefetchOrPreload();
@@ -130,8 +126,6 @@ void HTMLLinkElement::UnbindFromTree(bool aNullParent) {
                     eIgnoreCase)) {
       oldDoc->LocalizationLinkRemoved(this);
     }
-
-    CreateAndDispatchEvent(u"DOMLinkRemoved"_ns);
   }
 
   nsGenericHTMLElement::UnbindFromTree(aNullParent);
diff --git a/dom/html/HTMLLinkElement.h b/dom/html/HTMLLinkElement.h
index 49969b2c9ab0..6bbeb9a39750 100644
--- a/dom/html/HTMLLinkElement.h
+++ b/dom/html/HTMLLinkElement.h
@@ -40,7 +40,6 @@ class HTMLLinkElement final : public nsGenericHTMLElement,
   NS_DECL_ADDSIZEOFEXCLUDINGTHIS
 
   void LinkAdded();
-  void LinkRemoved();
 
   // nsINode
   nsresult Clone(dom::NodeInfo*, nsINode** aResult) const override;