--- a/editor/libeditor/ChangeAttributeTransaction.cpp
+++ b/editor/libeditor/ChangeAttributeTransaction.cpp
@@ -12,37 +12,38 @@
 
 namespace mozilla {
 
 using namespace dom;
 
 ChangeAttributeTransaction::ChangeAttributeTransaction(Element& aElement,
                                                        nsIAtom& aAttribute,
                                                        const nsAString* aValue)
-  : EditTxn()
+  : EditTransactionBase()
   , mElement(&aElement)
   , mAttribute(&aAttribute)
   , mValue(aValue ? *aValue : EmptyString())
   , mRemoveAttribute(!aValue)
   , mAttributeWasSet(false)
   , mUndoValue()
 {
 }
 
 ChangeAttributeTransaction::~ChangeAttributeTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(ChangeAttributeTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(ChangeAttributeTransaction,
+                                   EditTransactionBase,
                                    mElement)
 
-NS_IMPL_ADDREF_INHERITED(ChangeAttributeTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(ChangeAttributeTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(ChangeAttributeTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(ChangeAttributeTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ChangeAttributeTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 NS_IMETHODIMP
 ChangeAttributeTransaction::DoTransaction()
 {
   // Need to get the current value of the attribute and save it, and set
   // mAttributeWasSet
   mAttributeWasSet = mElement->GetAttr(kNameSpaceID_None, mAttribute,
                                        mUndoValue);

--- a/editor/libeditor/ChangeAttributeTransaction.h
+++ b/editor/libeditor/ChangeAttributeTransaction.h
@@ -1,17 +1,17 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef ChangeAttributeTransaction_h
 #define ChangeAttributeTransaction_h
 
-#include "EditTxn.h"                      // base class
+#include "EditTransactionBase.h"          // base class
 #include "mozilla/Attributes.h"           // override
 #include "nsCOMPtr.h"                     // nsCOMPtr members
 #include "nsCycleCollectionParticipant.h" // NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED
 #include "nsISupportsImpl.h"              // NS_DECL_ISUPPORTS_INHERITED
 #include "nsString.h"                     // nsString members
 
 class nsIAtom;
 
@@ -20,32 +20,33 @@ namespace mozilla {
 namespace dom {
 class Element;
 } // namespace dom
 
 /**
  * A transaction that changes an attribute of a content node.  This transaction
  * covers add, remove, and change attribute.
  */
-class ChangeAttributeTransaction final : public EditTxn
+class ChangeAttributeTransaction final : public EditTransactionBase
 {
 public:
   /**
    * @param aElement   the element whose attribute will be changed
    * @param aAttribute the name of the attribute to change
    * @param aValue     the new value for aAttribute, or null to remove
    */
   ChangeAttributeTransaction(dom::Element& aElement,
                              nsIAtom& aAttribute,
                              const nsAString* aValue);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeAttributeTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeAttributeTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
 
 private:
   virtual ~ChangeAttributeTransaction();
 
   // The element to operate upon
   nsCOMPtr<dom::Element> mElement;

--- a/editor/libeditor/ChangeStyleTransaction.cpp
+++ b/editor/libeditor/ChangeStyleTransaction.cpp
@@ -19,23 +19,24 @@
 #include "nsUnicharUtils.h"             // for nsCaseInsensitiveStringComparator
 
 namespace mozilla {
 
 using namespace dom;
 
 #define kNullCh (char16_t('\0'))
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(ChangeStyleTransaction, EditTxn, mElement)
+NS_IMPL_CYCLE_COLLECTION_INHERITED(ChangeStyleTransaction, EditTransactionBase,
+                                   mElement)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ChangeStyleTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
-NS_IMPL_ADDREF_INHERITED(ChangeStyleTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(ChangeStyleTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(ChangeStyleTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(ChangeStyleTransaction, EditTransactionBase)
 
 ChangeStyleTransaction::~ChangeStyleTransaction()
 {
 }
 
 // Answers true if aValue is in the string list of white-space separated values
 // aValueList.
 bool
@@ -117,17 +118,17 @@ ChangeStyleTransaction::RemoveValueFromL
   }
   aValues.Assign(outString);
 }
 
 ChangeStyleTransaction::ChangeStyleTransaction(Element& aElement,
                                                nsIAtom& aProperty,
                                                const nsAString& aValue,
                                                EChangeType aChangeType)
-  : EditTxn()
+  : EditTransactionBase()
   , mElement(&aElement)
   , mProperty(&aProperty)
   , mValue(aValue)
   , mRemoveProperty(aChangeType == eRemove)
   , mUndoValue()
   , mRedoValue()
   , mUndoAttributeWasSet(false)
   , mRedoAttributeWasSet(false)

--- a/editor/libeditor/ChangeStyleTransaction.h
+++ b/editor/libeditor/ChangeStyleTransaction.h
@@ -1,17 +1,17 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef ChangeStyleTransaction_h
 #define ChangeStyleTransaction_h
 
-#include "EditTxn.h"                      // base class
+#include "EditTransactionBase.h"          // base class
 #include "nsCOMPtr.h"                     // nsCOMPtr members
 #include "nsCycleCollectionParticipant.h" // various macros
 #include "nsString.h"                     // nsString members
 
 class nsAString;
 class nsIAtom;
 
 namespace mozilla {
@@ -19,24 +19,25 @@ namespace mozilla {
 namespace dom {
 class Element;
 } // namespace dom
 
 /**
  * A transaction that changes the value of a CSS inline style of a content
  * node.  This transaction covers add, remove, and change a property's value.
  */
-class ChangeStyleTransaction final : public EditTxn
+class ChangeStyleTransaction final : public EditTransactionBase
 {
 public:
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeStyleTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ChangeStyleTransaction,
+                                           EditTransactionBase)
 
   NS_DECL_ISUPPORTS_INHERITED
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
 
   enum EChangeType { eSet, eRemove };
 
   /**
    * @param aNode           [IN] the node whose style attribute will be changed
    * @param aProperty       [IN] the name of the property to change

--- a/editor/libeditor/CompositionTransaction.cpp
+++ b/editor/libeditor/CompositionTransaction.cpp
@@ -35,28 +35,28 @@ CompositionTransaction::CompositionTrans
   , mFixed(false)
 {
 }
 
 CompositionTransaction::~CompositionTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(CompositionTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(CompositionTransaction, EditTransactionBase,
                                    mTextNode)
 // mRangeList can't lead to cycles
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CompositionTransaction)
   if (aIID.Equals(NS_GET_IID(CompositionTransaction))) {
     foundInterface = static_cast<nsITransaction*>(this);
   } else
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
-NS_IMPL_ADDREF_INHERITED(CompositionTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(CompositionTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(CompositionTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(CompositionTransaction, EditTransactionBase)
 
 NS_IMETHODIMP
 CompositionTransaction::DoTransaction()
 {
   // Fail before making any changes if there's no selection controller
   nsCOMPtr<nsISelectionController> selCon;
   mEditor.GetSelectionController(getter_AddRefs(selCon));
   NS_ENSURE_TRUE(selCon, NS_ERROR_NOT_INITIALIZED);

--- a/editor/libeditor/CompositionTransaction.h
+++ b/editor/libeditor/CompositionTransaction.h
@@ -1,17 +1,17 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef CompositionTransaction_h
 #define CompositionTransaction_h
 
-#include "EditTxn.h"                      // base class
+#include "EditTransactionBase.h"          // base class
 #include "nsCycleCollectionParticipant.h" // various macros
 #include "nsString.h"                     // mStringToInsert
 
 class nsEditor;
 
 #define NS_IMETEXTTXN_IID \
   { 0xb391355d, 0x346c, 0x43d1, \
     { 0x85, 0xed, 0x9e, 0x65, 0xbe, 0xe7, 0x7e, 0x48 } }
@@ -25,17 +25,17 @@ class Text;
 } // namespace dom
 
 /**
  * CompositionTransaction stores all edit for a composition, i.e.,
  * from compositionstart event to compositionend event.  E.g., inserting a
  * composition string, modifying the composition string or its IME selection
  * ranges and commit or cancel the composition.
  */
-class CompositionTransaction final : public EditTxn
+class CompositionTransaction final : public EditTransactionBase
 {
 public:
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IMETEXTTXN_IID)
 
   /**
    * @param aTextNode           The text content node.
    * @param aOffset             The location in aTextNode to do the insertion.
    * @param aReplaceLength      The length of text to replace. 0 means not
@@ -46,21 +46,22 @@ public:
    * @param aEditor             Used to get and set the selection.
    */
   CompositionTransaction(dom::Text& aTextNode,
                          uint32_t aOffset, uint32_t aReplaceLength,
                          TextRangeArray* aTextRangeArray,
                          const nsAString& aString,
                          nsEditor& aEditor);
 
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CompositionTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CompositionTransaction,
+                                           EditTransactionBase)
 
   NS_DECL_ISUPPORTS_INHERITED
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override;
 
   void MarkFixed();
 
   static nsresult SetIMESelection(nsEditor& aEditor,
                                   dom::Text* aTextNode,
                                   uint32_t aOffsetInNode,

--- a/editor/libeditor/CreateElementTransaction.cpp
+++ b/editor/libeditor/CreateElementTransaction.cpp
@@ -31,37 +31,38 @@
 namespace mozilla {
 
 using namespace dom;
 
 CreateElementTransaction::CreateElementTransaction(nsEditor& aEditor,
                                                    nsIAtom& aTag,
                                                    nsINode& aParent,
                                                    int32_t aOffsetInParent)
-  : EditTxn()
+  : EditTransactionBase()
   , mEditor(&aEditor)
   , mTag(&aTag)
   , mParent(&aParent)
   , mOffsetInParent(aOffsetInParent)
 {
 }
 
 CreateElementTransaction::~CreateElementTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(CreateElementTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(CreateElementTransaction,
+                                   EditTransactionBase,
                                    mParent,
                                    mNewNode,
                                    mRefNode)
 
-NS_IMPL_ADDREF_INHERITED(CreateElementTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(CreateElementTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(CreateElementTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(CreateElementTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(CreateElementTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 
 NS_IMETHODIMP
 CreateElementTransaction::DoTransaction()
 {
   MOZ_ASSERT(mEditor && mTag && mParent);
 
   mNewNode = mEditor->CreateHTMLContent(mTag);

--- a/editor/libeditor/CreateElementTransaction.h
+++ b/editor/libeditor/CreateElementTransaction.h
@@ -1,17 +1,17 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef CreateElementTransaction_h
 #define CreateElementTransaction_h
 
-#include "EditTxn.h"
+#include "EditTransactionBase.h"
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsISupportsImpl.h"
 
 class nsEditor;
 class nsIAtom;
 class nsIContent;
 class nsINode;
@@ -20,17 +20,17 @@ class nsINode;
  * A transaction that creates a new node in the content tree.
  */
 namespace mozilla {
 
 namespace dom {
 class Element;
 } // namespace dom
 
-class CreateElementTransaction final : public EditTxn
+class CreateElementTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aEditor         The provider of basic editing functionality.
    * @param aTag            The tag (P, HR, TABLE, etc.) for the new element.
    * @param aParent         The node into which the new element will be
    *                        inserted.
@@ -39,19 +39,20 @@ public:
    *                        child.
    */
   CreateElementTransaction(nsEditor& aEditor,
                            nsIAtom& aTag,
                            nsINode& aParent,
                            int32_t aOffsetInParent);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CreateElementTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CreateElementTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
 
   already_AddRefed<dom::Element> GetNewNode();
 
 protected:
   virtual ~CreateElementTransaction();
 

--- a/editor/libeditor/DeleteNodeTransaction.cpp
+++ b/editor/libeditor/DeleteNodeTransaction.cpp
@@ -17,25 +17,25 @@ DeleteNodeTransaction::DeleteNodeTransac
   , mRangeUpdater(nullptr)
 {
 }
 
 DeleteNodeTransaction::~DeleteNodeTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteNodeTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteNodeTransaction, EditTransactionBase,
                                    mNode,
                                    mParent,
                                    mRefNode)
 
-NS_IMPL_ADDREF_INHERITED(DeleteNodeTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(DeleteNodeTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(DeleteNodeTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(DeleteNodeTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeleteNodeTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 nsresult
 DeleteNodeTransaction::Init(nsEditor* aEditor,
                             nsINode* aNode,
                             nsRangeUpdater* aRangeUpdater)
 {
   NS_ENSURE_TRUE(aEditor && aNode, NS_ERROR_NULL_POINTER);
   mEditor = aEditor;

--- a/editor/libeditor/DeleteNodeTransaction.h
+++ b/editor/libeditor/DeleteNodeTransaction.h
@@ -1,48 +1,49 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef DeleteNodeTransaction_h
 #define DeleteNodeTransaction_h
 
-#include "EditTxn.h"
+#include "EditTransactionBase.h"
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsIContent.h"
 #include "nsINode.h"
 #include "nsISupportsImpl.h"
 #include "nscore.h"
 
 class nsEditor;
 class nsRangeUpdater;
 
 namespace mozilla {
 
 /**
  * A transaction that deletes a single element
  */
-class DeleteNodeTransaction final : public EditTxn
+class DeleteNodeTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aElement        The node to delete.
    */
   nsresult Init(nsEditor* aEditor, nsINode* aNode,
                 nsRangeUpdater* aRangeUpdater);
 
   DeleteNodeTransaction();
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteNodeTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteNodeTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
 
 protected:
   virtual ~DeleteNodeTransaction();
 
   // The element to delete.
   nsCOMPtr<nsINode> mNode;

--- a/editor/libeditor/DeleteRangeTransaction.h
+++ b/editor/libeditor/DeleteRangeTransaction.h
@@ -2,17 +2,16 @@
 /* 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 DeleteRangeTransaction_h
 #define DeleteRangeTransaction_h
 
 #include "EditAggregateTransaction.h"
-#include "EditTxn.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsID.h"
 #include "nsIEditor.h"
 #include "nsISupportsImpl.h"
 #include "nsRange.h"
 #include "nscore.h"
 
 class nsEditor;
@@ -37,17 +36,17 @@ public:
                 nsRangeUpdater* aRangeUpdater);
 
   DeleteRangeTransaction();
 
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteRangeTransaction,
                                            EditAggregateTransaction)
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
 
   virtual void LastRelease() override
   {
     mRange = nullptr;
     EditAggregateTransaction::LastRelease();
   }

--- a/editor/libeditor/DeleteTextTransaction.cpp
+++ b/editor/libeditor/DeleteTextTransaction.cpp
@@ -29,21 +29,21 @@ DeleteTextTransaction::DeleteTextTransac
   , mOffset(aOffset)
   , mNumCharsToDelete(aNumCharsToDelete)
   , mRangeUpdater(aRangeUpdater)
 {
   NS_ASSERTION(mCharData->Length() >= aOffset + aNumCharsToDelete,
                "Trying to delete more characters than in node");
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteTextTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(DeleteTextTransaction, EditTransactionBase,
                                    mCharData)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DeleteTextTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 nsresult
 DeleteTextTransaction::Init()
 {
   // Do nothing if the node is read-only
   if (!mEditor.IsModifiableNode(mCharData)) {
     return NS_ERROR_FAILURE;
   }

--- a/editor/libeditor/DeleteTextTransaction.h
+++ b/editor/libeditor/DeleteTextTransaction.h
@@ -1,33 +1,33 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef DeleteTextTransaction_h
 #define DeleteTextTransaction_h
 
-#include "EditTxn.h"
+#include "EditTransactionBase.h"
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsGenericDOMDataNode.h"
 #include "nsID.h"
 #include "nsString.h"
 #include "nscore.h"
 
 class nsEditor;
 class nsRangeUpdater;
 
 namespace mozilla {
 
 /**
  * A transaction that removes text from a content node.
  */
-class DeleteTextTransaction final : public EditTxn
+class DeleteTextTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aEditor             The provider of basic editing operations.
    * @param aElement            The content node to remove text from.
    * @param aOffset             The location in aElement to begin the deletion.
    * @param aNumCharsToDelete   The number of characters to delete.  Not the
@@ -36,20 +36,21 @@ public:
   DeleteTextTransaction(nsEditor& aEditor,
                         nsGenericDOMDataNode& aCharData,
                         uint32_t aOffset,
                         uint32_t aNumCharsToDelete,
                         nsRangeUpdater* aRangeUpdater);
 
   nsresult Init();
 
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteTextTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(DeleteTextTransaction,
+                                           EditTransactionBase)
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   uint32_t GetOffset() { return mOffset; }
 
   uint32_t GetNumCharsToDelete() { return mNumCharsToDelete; }
 
 protected:
   // The provider of basic editing operations.
   nsEditor& mEditor;

--- a/editor/libeditor/EditAggregateTransaction.cpp
+++ b/editor/libeditor/EditAggregateTransaction.cpp
@@ -16,23 +16,24 @@ namespace mozilla {
 EditAggregateTransaction::EditAggregateTransaction()
 {
 }
 
 EditAggregateTransaction::~EditAggregateTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(EditAggregateTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(EditAggregateTransaction,
+                                   EditTransactionBase,
                                    mChildren)
 
-NS_IMPL_ADDREF_INHERITED(EditAggregateTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(EditAggregateTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(EditAggregateTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(EditAggregateTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(EditAggregateTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 NS_IMETHODIMP
 EditAggregateTransaction::DoTransaction()
 {
   nsresult result=NS_OK;  // it's legal (but not very useful) to have an empty child list
   for (uint32_t i = 0, length = mChildren.Length(); i < length; ++i)
   {
     nsITransaction *txn = mChildren[i];
@@ -104,23 +105,23 @@ EditAggregateTransaction::GetTxnDescript
     mName->ToString(name);
     aString += name;
   }
 
   return NS_OK;
 }
 
 NS_IMETHODIMP
-EditAggregateTransaction::AppendChild(EditTxn* aTransaction)
+EditAggregateTransaction::AppendChild(EditTransactionBase* aTransaction)
 {
   if (!aTransaction) {
     return NS_ERROR_NULL_POINTER;
   }
 
-  RefPtr<EditTxn> *slot = mChildren.AppendElement();
+  RefPtr<EditTransactionBase>* slot = mChildren.AppendElement();
   if (!slot) {
     return NS_ERROR_OUT_OF_MEMORY;
   }
 
   *slot = aTransaction;
   return NS_OK;
 }
 

--- a/editor/libeditor/EditAggregateTransaction.h
+++ b/editor/libeditor/EditAggregateTransaction.h
@@ -1,57 +1,58 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef EditAggregateTransaction_h
 #define EditAggregateTransaction_h
 
-#include "EditTxn.h"
+#include "EditTransactionBase.h"
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsIAtom.h"
 #include "nsISupportsImpl.h"
 #include "nsTArray.h"
 #include "nscore.h"
 
 class nsITransaction;
 
 namespace mozilla {
 
 /**
  * base class for all document editing transactions that require aggregation.
  * provides a list of child transactions.
  */
-class EditAggregateTransaction : public EditTxn
+class EditAggregateTransaction : public EditTransactionBase
 {
 public:
   EditAggregateTransaction();
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(EditAggregateTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(EditAggregateTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
   NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override;
 
   /**
    * Append a transaction to this aggregate.
    */
-  NS_IMETHOD AppendChild(EditTxn* aTxn);
+  NS_IMETHOD AppendChild(EditTransactionBase* aTransaction);
 
   /**
    * Get the name assigned to this transaction.
    */
   NS_IMETHOD GetName(nsIAtom** aName);
 
 protected:
   virtual ~EditAggregateTransaction();
 
-  nsTArray<RefPtr<EditTxn>> mChildren;
+  nsTArray<RefPtr<EditTransactionBase>> mChildren;
   nsCOMPtr<nsIAtom> mName;
 };
 
 } // namespace mozilla
 
 #endif // #ifndef EditAggregateTransaction_h

rename from editor/libeditor/EditTxn.cpp
rename to editor/libeditor/EditTransactionBase.cpp
--- a/editor/libeditor/EditTxn.cpp
+++ b/editor/libeditor/EditTransactionBase.cpp
@@ -1,50 +1,55 @@
 /* -*- Mode: C++; 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/. */
 
-#include "EditTxn.h"
+#include "EditTransactionBase.h"
 #include "nsError.h"
 #include "nsISupportsBase.h"
 
-NS_IMPL_CYCLE_COLLECTION_CLASS(EditTxn)
+namespace mozilla {
 
-NS_IMPL_CYCLE_COLLECTION_UNLINK_0(EditTxn)
-NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(EditTxn)
+NS_IMPL_CYCLE_COLLECTION_CLASS(EditTransactionBase)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_0(EditTransactionBase)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(EditTransactionBase)
   // We don't have anything to traverse, but some of our subclasses do.
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
-NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(EditTxn)
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(EditTransactionBase)
   NS_INTERFACE_MAP_ENTRY(nsITransaction)
   NS_INTERFACE_MAP_ENTRY(nsPIEditorTransaction)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsITransaction)
 NS_INTERFACE_MAP_END
 
-NS_IMPL_CYCLE_COLLECTING_ADDREF(EditTxn)
-NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(EditTxn, LastRelease())
+NS_IMPL_CYCLE_COLLECTING_ADDREF(EditTransactionBase)
+NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(EditTransactionBase,
+                                                   LastRelease())
 
-EditTxn::~EditTxn()
+EditTransactionBase::~EditTransactionBase()
 {
 }
 
 NS_IMETHODIMP
-EditTxn::RedoTransaction(void)
+EditTransactionBase::RedoTransaction()
 {
   return DoTransaction();
 }
 
 NS_IMETHODIMP
-EditTxn::GetIsTransient(bool *aIsTransient)
+EditTransactionBase::GetIsTransient(bool* aIsTransient)
 {
   *aIsTransient = false;
 
   return NS_OK;
 }
 
 NS_IMETHODIMP
-EditTxn::Merge(nsITransaction *aTransaction, bool *aDidMerge)
+EditTransactionBase::Merge(nsITransaction* aTransaction, bool* aDidMerge)
 {
   *aDidMerge = false;
 
   return NS_OK;
 }
+
+} // namespace mozilla

rename from editor/libeditor/EditTxn.h
rename to editor/libeditor/EditTransactionBase.h
--- a/editor/libeditor/EditTxn.h
+++ b/editor/libeditor/EditTransactionBase.h
@@ -1,40 +1,44 @@
 /* -*- Mode: C++; 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/. */
 
-#ifndef EditTxn_h__
-#define EditTxn_h__
+#ifndef EditTransactionBase_h
+#define EditTransactionBase_h
 
 #include "nsCycleCollectionParticipant.h"
 #include "nsISupportsImpl.h"
 #include "nsITransaction.h"
 #include "nsPIEditorTransaction.h"
 #include "nscore.h"
 
+namespace mozilla {
+
 /**
  * Base class for all document editing transactions.
  */
-class EditTxn : public nsITransaction,
-                public nsPIEditorTransaction
+class EditTransactionBase : public nsITransaction
+                          , public nsPIEditorTransaction
 {
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(EditTxn, nsITransaction)
+  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(EditTransactionBase, nsITransaction)
 
   virtual void LastRelease() {}
 
   NS_IMETHOD RedoTransaction(void) override;
-  NS_IMETHOD GetIsTransient(bool *aIsTransient) override;
-  NS_IMETHOD Merge(nsITransaction *aTransaction, bool *aDidMerge) override;
+  NS_IMETHOD GetIsTransient(bool* aIsTransient) override;
+  NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override;
 
 protected:
-  virtual ~EditTxn();
+  virtual ~EditTransactionBase();
 };
 
-#define NS_DECL_EDITTXN \
+} // namespace mozilla
+
+#define NS_DECL_EDITTRANSACTIONBASE \
   NS_IMETHOD DoTransaction() override; \
   NS_IMETHOD UndoTransaction() override; \
-  NS_IMETHOD GetTxnDescription(nsAString& aTxnDescription) override;
+  NS_IMETHOD GetTxnDescription(nsAString& aTransactionDescription) override;
 
-#endif
+#endif // #ifndef EditTransactionBase_h

--- a/editor/libeditor/InsertNodeTransaction.cpp
+++ b/editor/libeditor/InsertNodeTransaction.cpp
@@ -30,24 +30,24 @@ InsertNodeTransaction::InsertNodeTransac
   , mEditor(aEditor)
 {
 }
 
 InsertNodeTransaction::~InsertNodeTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(InsertNodeTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(InsertNodeTransaction, EditTransactionBase,
                                    mNode,
                                    mParent)
 
-NS_IMPL_ADDREF_INHERITED(InsertNodeTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(InsertNodeTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(InsertNodeTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(InsertNodeTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(InsertNodeTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 NS_IMETHODIMP
 InsertNodeTransaction::DoTransaction()
 {
   MOZ_ASSERT(mNode && mParent);
 
   uint32_t count = mParent->GetChildCount();
   if (mOffset > static_cast<int32_t>(count) || mOffset == -1) {

--- a/editor/libeditor/InsertNodeTransaction.h
+++ b/editor/libeditor/InsertNodeTransaction.h
@@ -1,45 +1,46 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef InsertNodeTransaction_h
 #define InsertNodeTransaction_h
 
-#include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
+#include "EditTransactionBase.h"        // for EditTransactionBase, etc
 #include "nsCOMPtr.h"                   // for nsCOMPtr
 #include "nsCycleCollectionParticipant.h"
 #include "nsIContent.h"                 // for nsIContent
 #include "nsISupportsImpl.h"            // for NS_DECL_ISUPPORTS_INHERITED
 
 class nsEditor;
 
 namespace mozilla {
 
 /**
  * A transaction that inserts a single element
  */
-class InsertNodeTransaction final : public EditTxn
+class InsertNodeTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aNode       The node to insert.
    * @param aParent     The node to insert into.
    * @param aOffset     The offset in aParent to insert aNode.
    */
   InsertNodeTransaction(nsIContent& aNode, nsINode& aParent, int32_t aOffset,
                         nsEditor& aEditor);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(InsertNodeTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(InsertNodeTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
 protected:
   virtual ~InsertNodeTransaction();
 
   // The element to insert.
   nsCOMPtr<nsIContent> mNode;
 
   // The node into which the new node will be inserted.

--- a/editor/libeditor/InsertTextTransaction.cpp
+++ b/editor/libeditor/InsertTextTransaction.cpp
@@ -27,26 +27,26 @@ InsertTextTransaction::InsertTextTransac
   , mEditor(aEditor)
 {
 }
 
 InsertTextTransaction::~InsertTextTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(InsertTextTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(InsertTextTransaction, EditTransactionBase,
                                    mTextNode)
 
-NS_IMPL_ADDREF_INHERITED(InsertTextTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(InsertTextTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(InsertTextTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(InsertTextTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(InsertTextTransaction)
   if (aIID.Equals(NS_GET_IID(InsertTextTransaction))) {
     foundInterface = static_cast<nsITransaction*>(this);
   } else
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 
 NS_IMETHODIMP
 InsertTextTransaction::DoTransaction()
 {
   nsresult res = mTextNode->InsertData(mOffset, mStringToInsert);
   NS_ENSURE_SUCCESS(res, res);
 

--- a/editor/libeditor/InsertTextTransaction.h
+++ b/editor/libeditor/InsertTextTransaction.h
@@ -1,17 +1,17 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef InsertTextTransaction_h
 #define InsertTextTransaction_h
 
-#include "EditTxn.h"                    // base class
+#include "EditTransactionBase.h"        // base class
 #include "nsCycleCollectionParticipant.h" // various macros
 #include "nsID.h"                       // NS_DECLARE_STATIC_IID_ACCESSOR
 #include "nsISupportsImpl.h"            // NS_DECL_ISUPPORTS_INHERITED
 #include "nsString.h"                   // nsString members
 #include "nscore.h"                     // NS_IMETHOD, nsAString
 
 class nsEditor;
 class nsITransaction;
@@ -24,34 +24,35 @@ namespace mozilla {
 
 namespace dom {
 class Text;
 } // namespace dom
 
 /**
  * A transaction that inserts text into a content node.
  */
-class InsertTextTransaction final : public EditTxn
+class InsertTextTransaction final : public EditTransactionBase
 {
 public:
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_INSERTTEXTTXN_IID)
 
   /**
    * @param aElement        The text content node.
    * @param aOffset         The location in aElement to do the insertion.
    * @param aString         The new text to insert.
    * @param aPresShell      Used to get and set the selection.
    */
   InsertTextTransaction(dom::Text& aTextNode, uint32_t aOffset,
                         const nsAString& aString, nsEditor& aEditor);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(InsertTextTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(InsertTextTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override;
 
   /**
    * Return the string data associated with this transaction.
    */
   void GetData(nsString& aResult);
 

--- a/editor/libeditor/JoinNodeTransaction.cpp
+++ b/editor/libeditor/JoinNodeTransaction.cpp
@@ -6,39 +6,39 @@
 #include "JoinNodeTransaction.h"
 #include "nsAString.h"
 #include "nsDebug.h"                    // for NS_ASSERTION, etc
 #include "nsEditor.h"                   // for nsEditor
 #include "nsError.h"                    // for NS_ERROR_NULL_POINTER, etc
 #include "nsIContent.h"                 // for nsIContent
 #include "nsIDOMCharacterData.h"        // for nsIDOMCharacterData
 #include "nsIEditor.h"                  // for nsEditor::IsModifiableNode
-#include "nsISupportsImpl.h"            // for EditTxn::QueryInterface, etc
+#include "nsISupportsImpl.h"            // for QueryInterface, etc
 
 namespace mozilla {
 
 using namespace dom;
 
 JoinNodeTransaction::JoinNodeTransaction(nsEditor& aEditor,
                                          nsINode& aLeftNode,
                                          nsINode& aRightNode)
   : mEditor(aEditor)
   , mLeftNode(&aLeftNode)
   , mRightNode(&aRightNode)
   , mOffset(0)
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(JoinNodeTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(JoinNodeTransaction, EditTransactionBase,
                                    mLeftNode,
                                    mRightNode,
                                    mParent)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JoinNodeTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 nsresult
 JoinNodeTransaction::CheckValidity()
 {
   if (!mEditor.IsModifiableNode(mLeftNode->GetParentNode())) {
     return NS_ERROR_FAILURE;
   }
   return NS_OK;

--- a/editor/libeditor/JoinNodeTransaction.h
+++ b/editor/libeditor/JoinNodeTransaction.h
@@ -1,53 +1,54 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef JoinNodeTransaction_h
 #define JoinNodeTransaction_h
 
-#include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
+#include "EditTransactionBase.h"        // for EditTransactionBase, etc
 #include "nsCOMPtr.h"                   // for nsCOMPtr
 #include "nsCycleCollectionParticipant.h"
 #include "nsID.h"                       // for REFNSIID
 #include "nscore.h"                     // for NS_IMETHOD
 
 class nsEditor;
 class nsINode;
 
 namespace mozilla {
 
 /**
  * A transaction that joins two nodes E1 (left node) and E2 (right node) into a
  * single node E.  The children of E are the children of E1 followed by the
  * children of E2.  After DoTransaction() and RedoTransaction(), E1 is removed
  * from the content tree and E2 remains.
  */
-class JoinNodeTransaction final : public EditTxn
+class JoinNodeTransaction final : public EditTransactionBase
 {
 public:
   /**
    * @param aEditor         The provider of core editing operations.
    * @param aLeftNode       The first of two nodes to join.
    * @param aRightNode      The second of two nodes to join.
    */
   JoinNodeTransaction(nsEditor& aEditor,
                       nsINode& aLeftNode, nsINode& aRightNode);
 
   /**
    * Call this after constructing to ensure the inputs are correct.
    */
   nsresult CheckValidity();
 
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(JoinNodeTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(JoinNodeTransaction,
+                                           EditTransactionBase)
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
 protected:
   nsEditor&  mEditor;
 
   // The nodes to operate upon.  After the merge, mRightNode remains and
   // mLeftNode is removed from the content tree.
   nsCOMPtr<nsINode> mLeftNode;
   nsCOMPtr<nsINode> mRightNode;

--- a/editor/libeditor/PlaceholderTransaction.cpp
+++ b/editor/libeditor/PlaceholderTransaction.cpp
@@ -120,76 +120,72 @@ PlaceholderTransaction::Merge(nsITransac
   // check to see if aTransaction is one of the editor's
   // private transactions. If not, we want to avoid merging
   // the foreign transaction into our placeholder since we
   // don't know what it does.
 
   nsCOMPtr<nsPIEditorTransaction> pTxn = do_QueryInterface(aTransaction);
   NS_ENSURE_TRUE(pTxn, NS_OK); // it's foreign so just bail!
 
-  EditTxn *editTxn = (EditTxn*)aTransaction;  //XXX: hack, not safe!  need nsIEditTransaction!
+  // XXX: hack, not safe!  need nsIEditTransaction!
+  EditTransactionBase* editTransactionBase = (EditTransactionBase*)aTransaction;
   // determine if this incoming txn is a placeholder txn
-  nsCOMPtr<nsIAbsorbingTransaction> plcTxn = do_QueryObject(editTxn);
+  nsCOMPtr<nsIAbsorbingTransaction> absorbingTransaction =
+    do_QueryObject(editTransactionBase);
 
-  // we are absorbing all txn's if mAbsorb is lit.
-  if (mAbsorb)
-  {
+  // We are absorbing all transactions if mAbsorb is lit.
+  if (mAbsorb) {
     RefPtr<CompositionTransaction> otherTransaction =
       do_QueryObject(aTransaction);
     if (otherTransaction) {
       // special handling for CompositionTransaction's: they need to merge with
       // any previous CompositionTransaction in this placeholder, if possible.
       if (!mCompositionTransaction) {
         // this is the first IME txn in the placeholder
         mCompositionTransaction = otherTransaction;
-        AppendChild(editTxn);
+        AppendChild(editTransactionBase);
       } else {
         bool didMerge;
         mCompositionTransaction->Merge(otherTransaction, &didMerge);
         if (!didMerge) {
           // it wouldn't merge.  Earlier IME txn is already committed and will
           // not absorb further IME txns.  So just stack this one after it
           // and remember it as a candidate for further merges.
           mCompositionTransaction = otherTransaction;
-          AppendChild(editTxn);
+          AppendChild(editTransactionBase);
         }
       }
-    } else if (!plcTxn) {
+    } else if (!absorbingTransaction) {
       // See bug 171243: just drop incoming placeholders on the floor.
       // Their children will be swallowed by this preexisting one.
-      AppendChild(editTxn);
+      AppendChild(editTransactionBase);
     }
     *aDidMerge = true;
 //  RememberEndingSelection();
 //  efficiency hack: no need to remember selection here, as we haven't yet
 //  finished the initial batch and we know we will be told when the batch ends.
 //  we can remeber the selection then.
-  }
-  else
-  { // merge typing or IME or deletion transactions if the selection matches
+  } else {
+    // merge typing or IME or deletion transactions if the selection matches
     if (((mName.get() == nsGkAtoms::TypingTxnName) ||
          (mName.get() == nsGkAtoms::IMETxnName)    ||
          (mName.get() == nsGkAtoms::DeleteTxnName))
-         && !mCommitted )
-    {
-      nsCOMPtr<nsIAbsorbingTransaction> plcTxn = do_QueryObject(editTxn);
-      if (plcTxn) {
+         && !mCommitted) {
+      if (absorbingTransaction) {
         nsCOMPtr<nsIAtom> atom;
-        plcTxn->GetTxnName(getter_AddRefs(atom));
-        if (atom && (atom == mName))
-        {
+        absorbingTransaction->GetTxnName(getter_AddRefs(atom));
+        if (atom && atom == mName) {
           // check if start selection of next placeholder matches
           // end selection of this placeholder
           bool isSame;
-          plcTxn->StartSelectionEquals(&mEndSel, &isSame);
-          if (isSame)
-          {
+          absorbingTransaction->StartSelectionEquals(&mEndSel, &isSame);
+          if (isSame) {
             mAbsorb = true;  // we need to start absorbing again
-            plcTxn->ForwardEndBatchTo(this);
-            // AppendChild(editTxn);
+            absorbingTransaction->ForwardEndBatchTo(this);
+            // AppendChild(editTransactionBase);
             // see bug 171243: we don't need to merge placeholders
             // into placeholders.  We just reactivate merging in the pre-existing
             // placeholder and drop the new one on the floor.  The EndPlaceHolderBatch()
             // call on the new placeholder will be forwarded to this older one.
             RememberEndingSelection();
             *aDidMerge = true;
           }
         }

--- a/editor/libeditor/PlaceholderTransaction.h
+++ b/editor/libeditor/PlaceholderTransaction.h
@@ -34,17 +34,17 @@ public:
   NS_DECL_ISUPPORTS_INHERITED
 
   PlaceholderTransaction();
 
   NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(PlaceholderTransaction,
                                            EditAggregateTransaction)
 // ------------ EditAggregateTransaction -----------------------
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
   NS_IMETHOD Merge(nsITransaction* aTransaction, bool* aDidMerge) override;
 
 // ------------ nsIAbsorbingTransaction -----------------------
 
   NS_IMETHOD Init(nsIAtom* aName, nsSelectionState* aSelState,
                   nsEditor* aEditor) override;

--- a/editor/libeditor/SetDocumentTitleTransaction.h
+++ b/editor/libeditor/SetDocumentTitleTransaction.h
@@ -1,46 +1,46 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef SetDocumentTitleTransaction_h
 #define SetDocumentTitleTransaction_h
 
-#include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
+#include "EditTransactionBase.h"        // for EditTransactionBase, etc
 #include "nsString.h"                   // for nsString
 #include "nscore.h"                     // for NS_IMETHOD, nsAString, etc
 
 class nsIHTMLEditor;
 
 namespace mozilla {
 
 /**
  * A transaction that changes the document's title,
  *  which is a text node under the <title> tag in a page's <head> section
  * provides default concrete behavior for all nsITransaction methods.
  */
-class SetDocumentTitleTransaction final : public EditTxn
+class SetDocumentTitleTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aEditor     The object providing core editing operations.
    * @param aValue      The new value for document title.
    */
   NS_IMETHOD Init(nsIHTMLEditor* aEditor,
                   const nsAString* aValue);
   SetDocumentTitleTransaction();
 
 private:
   nsresult SetDomTitle(const nsAString& aTitle);
 
 public:
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
   NS_IMETHOD GetIsTransient(bool *aIsTransient) override;
 
 protected:
 
   // The editor that created this transaction.
   nsIHTMLEditor* mEditor;

--- a/editor/libeditor/SplitNodeTransaction.cpp
+++ b/editor/libeditor/SplitNodeTransaction.cpp
@@ -24,24 +24,24 @@ SplitNodeTransaction::SplitNodeTransacti
   , mOffset(aOffset)
 {
 }
 
 SplitNodeTransaction::~SplitNodeTransaction()
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(SplitNodeTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(SplitNodeTransaction, EditTransactionBase,
                                    mParent,
                                    mNewLeftNode)
 
-NS_IMPL_ADDREF_INHERITED(SplitNodeTransaction, EditTxn)
-NS_IMPL_RELEASE_INHERITED(SplitNodeTransaction, EditTxn)
+NS_IMPL_ADDREF_INHERITED(SplitNodeTransaction, EditTransactionBase)
+NS_IMPL_RELEASE_INHERITED(SplitNodeTransaction, EditTransactionBase)
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(SplitNodeTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 NS_IMETHODIMP
 SplitNodeTransaction::DoTransaction()
 {
   // Create a new node
   ErrorResult rv;
   // Don't use .downcast directly because AsContent has an assertion we want
   nsCOMPtr<nsINode> clone = mExistingRightNode->CloneNode(false, rv);

--- a/editor/libeditor/SplitNodeTransaction.h
+++ b/editor/libeditor/SplitNodeTransaction.h
@@ -1,48 +1,49 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef SplitNodeTransaction_h
 #define SplitNodeTransaction_h
 
-#include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
+#include "EditTransactionBase.h"        // for EditTxn, etc
 #include "nsCOMPtr.h"                   // for nsCOMPtr
 #include "nsCycleCollectionParticipant.h"
 #include "nsISupportsImpl.h"            // for NS_DECL_ISUPPORTS_INHERITED
 #include "nscore.h"                     // for NS_IMETHOD
 
 class nsEditor;
 class nsIContent;
 class nsINode;
 
 namespace mozilla {
 
 /**
  * A transaction that splits a node into two identical nodes, with the children
  * divided between the new nodes.
  */
-class SplitNodeTransaction final : public EditTxn
+class SplitNodeTransaction final : public EditTransactionBase
 {
 public:
   /**
    * @param aEditor  The provider of core editing operations
    * @param aNode    The node to split
    * @param aOffset  The location within aNode to do the split.  aOffset may
    *                 refer to children of aNode, or content of aNode.  The left
    *                 node will have child|content 0..aOffset-1.
    */
   SplitNodeTransaction(nsEditor& aEditor, nsIContent& aNode, int32_t aOffset);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SplitNodeTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(SplitNodeTransaction,
+                                           EditTransactionBase)
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
   NS_IMETHOD RedoTransaction() override;
 
   nsIContent* GetNewNode();
 
 protected:
   virtual ~SplitNodeTransaction();
 

--- a/editor/libeditor/StyleSheetTransactions.cpp
+++ b/editor/libeditor/StyleSheetTransactions.cpp
@@ -50,21 +50,22 @@ RemoveStyleSheet(nsIEditor* aEditor, Sty
  * AddStyleSheetTransaction
  ******************************************************************************/
 
 AddStyleSheetTransaction::AddStyleSheetTransaction()
   : mEditor(nullptr)
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(AddStyleSheetTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(AddStyleSheetTransaction,
+                                   EditTransactionBase,
                                    mSheet)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(AddStyleSheetTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 NS_IMETHODIMP
 AddStyleSheetTransaction::Init(nsIEditor* aEditor,
                                StyleSheetHandle aSheet)
 {
   NS_ENSURE_TRUE(aEditor && aSheet, NS_ERROR_INVALID_ARG);
 
   mEditor = aEditor;
@@ -103,21 +104,22 @@ AddStyleSheetTransaction::GetTxnDescript
  * RemoveStyleSheetTransaction
  ******************************************************************************/
 
 RemoveStyleSheetTransaction::RemoveStyleSheetTransaction()
   : mEditor(nullptr)
 {
 }
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(RemoveStyleSheetTransaction, EditTxn,
+NS_IMPL_CYCLE_COLLECTION_INHERITED(RemoveStyleSheetTransaction,
+                                   EditTransactionBase,
                                    mSheet)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(RemoveStyleSheetTransaction)
-NS_INTERFACE_MAP_END_INHERITING(EditTxn)
+NS_INTERFACE_MAP_END_INHERITING(EditTransactionBase)
 
 NS_IMETHODIMP
 RemoveStyleSheetTransaction::Init(nsIEditor* aEditor,
                                   StyleSheetHandle aSheet)
 {
   NS_ENSURE_TRUE(aEditor && aSheet, NS_ERROR_INVALID_ARG);
 
   mEditor = aEditor;

--- a/editor/libeditor/StyleSheetTransactions.h
+++ b/editor/libeditor/StyleSheetTransactions.h
@@ -1,67 +1,69 @@
 /* -*- Mode: C++; 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/. */
 
 #ifndef StylesheetTransactions_h
 #define StylesheetTransactions_h
 
-#include "EditTxn.h"                    // for EditTxn, NS_DECL_EDITTXN
+#include "EditTransactionBase.h"        // for EditTransactionBase, etc
 #include "mozilla/StyleSheetHandle.h"   // for mozilla::StyleSheetHandle
 #include "nsCycleCollectionParticipant.h"
 #include "nsID.h"                       // for REFNSIID
 #include "nscore.h"                     // for NS_IMETHOD
 
 class nsIEditor;
 
 namespace mozilla {
 
-class AddStyleSheetTransaction final : public EditTxn
+class AddStyleSheetTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aEditor     The object providing core editing operations
    * @param aSheet      The stylesheet to add
     */
   NS_IMETHOD Init(nsIEditor* aEditor, StyleSheetHandle aSheet);
 
   AddStyleSheetTransaction();
 
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AddStyleSheetTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(AddStyleSheetTransaction,
+                                           EditTransactionBase)
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
 protected:
   // The editor that created this transaction.
   nsIEditor* mEditor;
   // The style sheet to add.
   mozilla::StyleSheetHandle::RefPtr mSheet;
 };
 
 
-class RemoveStyleSheetTransaction final : public EditTxn
+class RemoveStyleSheetTransaction final : public EditTransactionBase
 {
 public:
   /**
    * Initialize the transaction.
    * @param aEditor     The object providing core editing operations.
    * @param aSheet      The stylesheet to remove.
    */
   NS_IMETHOD Init(nsIEditor* aEditor, StyleSheetHandle aSheet);
 
   RemoveStyleSheetTransaction();
 
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(RemoveStyleSheetTransaction, EditTxn)
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(RemoveStyleSheetTransaction,
+                                           EditTransactionBase)
   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
 
-  NS_DECL_EDITTXN
+  NS_DECL_EDITTRANSACTIONBASE
 
 protected:
   // The editor that created this transaction.
   nsIEditor* mEditor;
   // The style sheet to remove.
   StyleSheetHandle::RefPtr mSheet;
 
 };

--- a/editor/libeditor/moz.build
+++ b/editor/libeditor/moz.build
@@ -18,17 +18,17 @@ UNIFIED_SOURCES += [
     'ChangeStyleTransaction.cpp',
     'CompositionTransaction.cpp',
     'CreateElementTransaction.cpp',
     'DeleteNodeTransaction.cpp',
     'DeleteRangeTransaction.cpp',
     'DeleteTextTransaction.cpp',
     'EditAggregateTransaction.cpp',
     'EditorUtils.cpp',
-    'EditTxn.cpp',
+    'EditTransactionBase.cpp',
     'HTMLEditUtils.cpp',
     'InsertNodeTransaction.cpp',
     'InsertTextTransaction.cpp',
     'JoinNodeTransaction.cpp',
     'nsEditor.cpp',
     'nsEditorCommands.cpp',
     'nsEditorController.cpp',
     'nsEditorEventListener.cpp',

--- a/editor/libeditor/nsEditor.cpp
+++ b/editor/libeditor/nsEditor.cpp
@@ -13,17 +13,17 @@
 #include "ChangeAttributeTransaction.h" // for ChangeAttributeTransaction
 #include "CompositionTransaction.h"     // for CompositionTransaction
 #include "CreateElementTransaction.h"   // for CreateElementTransaction
 #include "DeleteNodeTransaction.h"      // for DeleteNodeTransaction
 #include "DeleteRangeTransaction.h"     // for DeleteRangeTransaction
 #include "DeleteTextTransaction.h"      // for DeleteTextTransaction
 #include "EditAggregateTransaction.h"   // for EditAggregateTransaction
 #include "EditorUtils.h"                // for AutoRules, etc
-#include "EditTxn.h"                    // for EditTxn
+#include "EditTransactionBase.h"        // for EditTransactionBase
 #include "InsertNodeTransaction.h"      // for InsertNodeTransaction
 #include "InsertTextTransaction.h"      // for InsertTextTransaction
 #include "JoinNodeTransaction.h"        // for JoinNodeTransaction
 #include "PlaceholderTransaction.h"     // for PlaceholderTransaction
 #include "SplitNodeTransaction.h"       // for SplitNodeTransaction
 #include "StyleSheetTransactions.h"     // for AddStyleSheetTransaction, etc
 #include "TextEditUtils.h"              // for TextEditUtils
 #include "mozFlushType.h"               // for mozFlushType::Flush_Frames
@@ -2403,17 +2403,17 @@ nsEditor::InsertTextImpl(const nsAString
 }
 
 
 nsresult
 nsEditor::InsertTextIntoTextNodeImpl(const nsAString& aStringToInsert,
                                      Text& aTextNode,
                                      int32_t aOffset, bool aSuppressIME)
 {
-  RefPtr<EditTxn> txn;
+  RefPtr<EditTransactionBase> transaction;
   bool isIMETransaction = false;
   int32_t replacedOffset = 0;
   int32_t replacedLength = 0;
   // aSuppressIME is used when editor must insert text, yet this text is not
   // part of the current IME operation. Example: adjusting whitespace around an
   // IME insertion.
   if (ShouldHandleIMEComposition() && !aSuppressIME) {
     if (!mIMETextNode) {
@@ -2431,53 +2431,53 @@ nsEditor::InsertTextIntoTextNodeImpl(con
       if (!mPhonetic) {
         mPhonetic = new nsString();
       }
       nsAutoString stringToInsert(aStringToInsert);
       stringToInsert.Mid(*mPhonetic,
                          textRange.mStartOffset, textRange.Length());
     }
 
-    txn = CreateTxnForComposition(aStringToInsert);
+    transaction = CreateTxnForComposition(aStringToInsert);
     isIMETransaction = true;
     // All characters of the composition string will be replaced with
     // aStringToInsert.  So, we need to emulate to remove the composition
     // string.
     replacedOffset = mIMETextOffset;
     replacedLength = mIMETextLength;
     mIMETextLength = aStringToInsert.Length();
   } else {
-    txn = CreateTxnForInsertText(aStringToInsert, aTextNode, aOffset);
+    transaction = CreateTxnForInsertText(aStringToInsert, aTextNode, aOffset);
   }
 
   // Let listeners know what's up
   for (auto& listener : mActionListeners) {
     listener->WillInsertText(
       static_cast<nsIDOMCharacterData*>(aTextNode.AsDOMNode()), aOffset,
       aStringToInsert);
   }
 
   // XXX We may not need these view batches anymore.  This is handled at a
   // higher level now I believe.
   BeginUpdateViewBatch();
-  nsresult res = DoTransaction(txn);
+  nsresult rv = DoTransaction(transaction);
   EndUpdateViewBatch();
 
   if (replacedLength) {
     mRangeUpdater.SelAdjDeleteText(
       static_cast<nsIDOMCharacterData*>(aTextNode.AsDOMNode()),
       replacedOffset, replacedLength);
   }
   mRangeUpdater.SelAdjInsertText(aTextNode, aOffset, aStringToInsert);
 
   // let listeners know what happened
   for (auto& listener : mActionListeners) {
     listener->DidInsertText(
       static_cast<nsIDOMCharacterData*>(aTextNode.AsDOMNode()),
-      aOffset, aStringToInsert, res);
+      aOffset, aStringToInsert, rv);
   }
 
   // Added some cruft here for bug 43366.  Layout was crashing because we left
   // an empty text node lying around in the document.  So I delete empty text
   // nodes caused by IME.  I have to mark the IME transaction as "fixed", which
   // means that furure IME txns won't merge with it.  This is because we don't
   // want future IME txns trying to put their text into a node that is no
   // longer in the document.  This does not break undo/redo, because all these
@@ -2485,21 +2485,21 @@ nsEditor::InsertTextIntoTextNodeImpl(con
   // already savvy to having multiple ime txns inside them.
 
   // Delete empty IME text node if there is one
   if (isIMETransaction && mIMETextNode) {
     uint32_t len = mIMETextNode->Length();
     if (!len) {
       DeleteNode(mIMETextNode);
       mIMETextNode = nullptr;
-      static_cast<CompositionTransaction*>(txn.get())->MarkFixed();
+      static_cast<CompositionTransaction*>(transaction.get())->MarkFixed();
     }
   }
 
-  return res;
+  return rv;
 }
 
 
 nsresult
 nsEditor::SelectEntireDocument(Selection* aSelection)
 {
   if (!aSelection) { return NS_ERROR_NULL_POINTER; }
 

--- a/editor/libeditor/nsHTMLCSSUtils.cpp
+++ b/editor/libeditor/nsHTMLCSSUtils.cpp
@@ -1,17 +1,16 @@
 /* -*- Mode: C++; 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/. */
 
 #include "nsHTMLCSSUtils.h"
 
 #include "ChangeStyleTransaction.h"
-#include "EditTxn.h"
 #include "mozilla/Assertions.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/css/Declaration.h"
 #include "mozilla/css/StyleRule.h"
 #include "mozilla/dom/Element.h"
 #include "mozilla/mozalloc.h"
 #include "nsAString.h"
 #include "nsCOMPtr.h"