--- a/editor/libeditor/EditAction.h
+++ b/editor/libeditor/EditAction.h
@@ -84,17 +84,20 @@ enum class EditSubAction : int32_t
 
   // eCreateOrRemoveBlock creates new block or removes existing block and
   // move its descendants to where the block was.
   eCreateOrRemoveBlock,
 
   // eRemoveList removes specific type of list but keep its content.
   eRemoveList,
 
-  makeDefListItem,
+  // eCreateOrChangeDefinitionList indicates to create new definition list or
+  // change existing list to a definition list.
+  eCreateOrChangeDefinitionList,
+
   insertElement,
   insertQuotation,
 
   htmlPaste = 3012,
   loadHTML,
   resetTextProperties,
   setAbsolutePosition,
   removeAbsolutePosition,

--- a/editor/libeditor/HTMLEditRules.cpp
+++ b/editor/libeditor/HTMLEditRules.cpp
@@ -87,17 +87,17 @@ IsStyleCachePreservingSubAction(EditSubA
   return aEditSubAction == EditSubAction::eDeleteSelectedContent ||
          aEditSubAction == EditSubAction::eInsertParagraphSeparator ||
          aEditSubAction == EditSubAction::eCreateOrChangeList ||
          aEditSubAction == EditSubAction::eIndent ||
          aEditSubAction == EditSubAction::eOutdent ||
          aEditSubAction == EditSubAction::eSetOrClearAlignment ||
          aEditSubAction == EditSubAction::eCreateOrRemoveBlock ||
          aEditSubAction == EditSubAction::eRemoveList ||
-         aEditSubAction == EditSubAction::makeDefListItem ||
+         aEditSubAction == EditSubAction::eCreateOrChangeDefinitionList ||
          aEditSubAction == EditSubAction::insertElement ||
          aEditSubAction == EditSubAction::insertQuotation;
 }
 
 static nsAtom&
 ParagraphSeparatorElement(ParagraphSeparator separator)
 {
   switch (separator) {
@@ -716,17 +716,17 @@ HTMLEditRules::WillDoAction(Selection* a
           NS_WARN_IF(!CanHandleEditAction())) {
         return NS_ERROR_EDITOR_DESTROYED;
       }
       if (NS_WARN_IF(NS_FAILED(rv))) {
         return rv;
       }
       return NS_OK;
     }
-    case EditSubAction::makeDefListItem:
+    case EditSubAction::eCreateOrChangeDefinitionList:
       return WillMakeDefListItem(aInfo.blockType,
                                  aInfo.entireList, aCancel, aHandled);
     case EditSubAction::insertElement: {
       nsresult rv = WillInsert(aCancel);
       if (NS_WARN_IF(rv == NS_ERROR_EDITOR_DESTROYED)) {
         return NS_ERROR_EDITOR_DESTROYED;
       }
       NS_WARNING_ASSERTION(NS_SUCCEEDED(rv), "WillInsert() failed");

--- a/editor/libeditor/HTMLEditor.cpp
+++ b/editor/libeditor/HTMLEditor.cpp
@@ -2152,27 +2152,28 @@ HTMLEditor::MakeDefinitionListItemWithTr
              &aTagName == nsGkAtoms::dd);
 
   // Protect the edit rules object from dying
   RefPtr<TextEditRules> rules(mRules);
 
   bool cancel, handled;
 
   AutoPlaceholderBatch beginBatching(this);
-  AutoTopLevelEditSubActionNotifier maybeTopLevelEditSubAction(
-                                      *this, EditSubAction::makeDefListItem,
-                                      nsIEditor::eNext);
+  AutoTopLevelEditSubActionNotifier
+    maybeTopLevelEditSubAction(*this,
+                               EditSubAction::eCreateOrChangeDefinitionList,
+                               nsIEditor::eNext);
 
   // pre-process
   RefPtr<Selection> selection = GetSelection();
   if (NS_WARN_IF(!selection)) {
     return NS_ERROR_FAILURE;
   }
   nsDependentAtomString tagName(&aTagName);
-  EditSubActionInfo subActionInfo(EditSubAction::makeDefListItem);
+  EditSubActionInfo subActionInfo(EditSubAction::eCreateOrChangeDefinitionList);
   subActionInfo.blockType = &tagName;
   nsresult rv =
     rules->WillDoAction(selection, subActionInfo, &cancel, &handled);
   if (cancel || NS_FAILED(rv)) {
     return rv;
   }
 
   if (!handled) {