[Extensions] Remove SyncIOThreadExtensionFunction

extensions/browser/extension_function.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/extension_function.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 623 matching lines @@
 
 ExtensionFunction::ResponseAction SyncExtensionFunction::Run() {
   return RespondNow(RunSync() ? ArgumentList(std::move(results_))
                               : Error(error_));
 }
 
 // static
 bool SyncExtensionFunction::ValidationFailure(SyncExtensionFunction* function) {
   return false;
 }
-
-SyncIOThreadExtensionFunction::SyncIOThreadExtensionFunction() {
-}
-
-SyncIOThreadExtensionFunction::~SyncIOThreadExtensionFunction() {
-}
-
-ExtensionFunction::ResponseAction SyncIOThreadExtensionFunction::Run() {
-  return RespondNow(RunSync() ? ArgumentList(std::move(results_))
-                              : Error(error_));
-}
-
-// static
-bool SyncIOThreadExtensionFunction::ValidationFailure(
-    SyncIOThreadExtensionFunction* function) {
-  return false;
-}