Bug 1505668 - part 1: Stop supporting "cmd_clearUndo" since nobody uses it r=m_kato

"cmd_clearUndo" is never used now (even including comm-central and BlueGriffon).
So, we can stop supporting this command and we can get rid of the command
handler, ClearUndoCommand.

Differential Revision: https://phabricator.services.mozilla.com/D20610

--HG--
extra : moz-landing-system : lando

editor/libeditor/EditorCommands.cpp

@@ -145,64 +145,6 @@ RedoCommand::GetCommandStateParams(const char* aCommandName,
   return aParams->AsCommandParams()->SetBool(STATE_ENABLED, canUndo);
 }
 
-/******************************************************************************
- * mozilla::ClearUndoCommand
- ******************************************************************************/
-
-NS_IMETHODIMP
-ClearUndoCommand::IsCommandEnabled(const char* aCommandName,
-                                   nsISupports* aCommandRefCon,
-                                   bool* aIsEnabled) {
-  if (NS_WARN_IF(!aIsEnabled)) {
-    return NS_ERROR_INVALID_ARG;
-  }
-  nsCOMPtr<nsIEditor> editor = do_QueryInterface(aCommandRefCon);
-  if (!editor) {
-    *aIsEnabled = false;
-    return NS_OK;
-  }
-  TextEditor* textEditor = editor->AsTextEditor();
-  MOZ_ASSERT(textEditor);
-  *aIsEnabled = textEditor->IsSelectionEditable();
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-ClearUndoCommand::DoCommand(const char* aCommandName,
-                            nsISupports* aCommandRefCon) {
-  nsCOMPtr<nsIEditor> editor = do_QueryInterface(aCommandRefCon);
-  if (!editor) {
-    return NS_ERROR_FAILURE;
-  }
-  TextEditor* textEditor = editor->AsTextEditor();
-  MOZ_ASSERT(textEditor);
-  // XXX Should we return NS_ERROR_FAILURE if ClearUndoRedo() returns false?
-  DebugOnly<bool> clearedUndoRedo = textEditor->ClearUndoRedo();
-  NS_WARNING_ASSERTION(clearedUndoRedo,
-                       "Failed to clear undo/redo transactions");
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-ClearUndoCommand::DoCommandParams(const char* aCommandName,
-                                  nsICommandParams* aParams,
-                                  nsISupports* aCommandRefCon) {
-  return DoCommand(aCommandName, aCommandRefCon);
-}
-
-NS_IMETHODIMP
-ClearUndoCommand::GetCommandStateParams(const char* aCommandName,
-                                        nsICommandParams* aParams,
-                                        nsISupports* aCommandRefCon) {
-  NS_ENSURE_ARG_POINTER(aParams);
-
-  bool enabled;
-  nsresult rv = IsCommandEnabled(aCommandName, aCommandRefCon, &enabled);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  return aParams->AsCommandParams()->SetBool(STATE_ENABLED, enabled);
-}
-
 /******************************************************************************
  * mozilla::CutCommand
  ******************************************************************************/

editor/libeditor/EditorCommands.h

@@ -57,7 +57,6 @@ class EditorCommandBase : public nsIControllerCommand {
 // basic editor commands
 NS_DECL_EDITOR_COMMAND(UndoCommand)
 NS_DECL_EDITOR_COMMAND(RedoCommand)
-NS_DECL_EDITOR_COMMAND(ClearUndoCommand)
 
 NS_DECL_EDITOR_COMMAND(CutCommand)
 NS_DECL_EDITOR_COMMAND(CutOrDeleteCommand)

editor/libeditor/EditorController.cpp

@@ -47,7 +47,6 @@ nsresult EditorController::RegisterEditingCommands(
 
   NS_REGISTER_ONE_COMMAND(UndoCommand, "cmd_undo");
   NS_REGISTER_ONE_COMMAND(RedoCommand, "cmd_redo");
-  NS_REGISTER_ONE_COMMAND(ClearUndoCommand, "cmd_clearUndo");
 
   NS_REGISTER_ONE_COMMAND(CutCommand, "cmd_cut");
   NS_REGISTER_ONE_COMMAND(CutOrDeleteCommand, "cmd_cutOrDelete");