AcceleratorProvider: Make GetAcceleratorForCommandId const.

chrome/browser/download/download_shelf_context_menu.cc

 // Copyright (c) 2012 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 "chrome/browser/download/download_shelf_context_menu.h"
 
 #include "build/build_config.h"
 #include "chrome/browser/download/download_item_model.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/common/content_features.h"
@@ skipping 70 matching lines @@
 void DownloadShelfContextMenu::ExecuteCommand(int command_id, int event_flags) {
   if (!download_commands_)
     return;
 
   download_commands_->ExecuteCommand(
       static_cast<DownloadCommands::Command>(command_id));
 }
 
 bool DownloadShelfContextMenu::GetAcceleratorForCommandId(
     int command_id,
-    ui::Accelerator* accelerator) {
+    ui::Accelerator* accelerator) const {
   return false;
 }
 
 bool DownloadShelfContextMenu::IsItemForCommandIdDynamic(int command_id) const {
   return false;
 }
 
 base::string16 DownloadShelfContextMenu::GetLabelForCommandId(
     int command_id) const {
   int id = -1;
@@ skipping 194 matching lines @@
   if (malicious_download_menu_model_)
     return malicious_download_menu_model_.get();
 
   malicious_download_menu_model_.reset(new ui::SimpleMenuModel(this));
   malicious_download_menu_model_->AddItem(
       DownloadCommands::LEARN_MORE_SCANNING,
       GetLabelForCommandId(DownloadCommands::LEARN_MORE_SCANNING));
 
   return malicious_download_menu_model_.get();
 }