AcceleratorProvider: Make GetAcceleratorForCommandId const.

chrome/browser/ui/toolbar/media_router_contextual_menu.cc

 // Copyright 2015 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 "base/logging.h"
 #include "base/metrics/user_metrics.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/extensions/component_migration_helper.h"
 #include "chrome/browser/media/router/media_router_factory.h"
 #include "chrome/browser/media/router/mojo/media_router_mojo_impl.h"
@@ skipping 67 matching lines @@
     SigninManagerBase* signin_manager =
         SigninManagerFactory::GetForProfile(browser_->profile());
     return signin_manager && signin_manager->IsAuthenticated();
   }
 #endif  // defined(GOOGLE_CHROME_BUILD)
   return true;
 }
 
 bool MediaRouterContextualMenu::GetAcceleratorForCommandId(
     int command_id,
-    ui::Accelerator* accelerator) {
+    ui::Accelerator* accelerator) const {
   return false;
 }
 
 void MediaRouterContextualMenu::ExecuteCommand(int command_id,
                                                int event_flags) {
   const char kAboutPageUrl[] =
       "https://www.google.com/chrome/devices/chromecast/";
   const char kCastHelpCenterPageUrl[] =
       "https://support.google.com/chromecast/topic/3447927";
   const char kCastLearnMorePageUrl[] =
@@ skipping 55 matching lines @@
                            std::string(url::kStandardSchemeSeparator) +
                            media_router->media_route_provider_extension_id() +
                            "/feedback.html");
   chrome::ShowSingletonTab(browser_, GURL(feedback_url));
 }
 
 void MediaRouterContextualMenu::RemoveMediaRouterComponentAction() {
   ToolbarActionsModel::Get(browser_->profile())->component_migration_helper()
       ->OnActionRemoved(ComponentToolbarActionsFactory::kMediaRouterActionId);
 }