[ToolbarActionViewController] Update return type of GetId().

chrome/browser/ui/views/toolbar/browser_actions_container.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 "chrome/browser/ui/views/toolbar/browser_actions_container.h"
 
 #include "base/compiler_specific.h"
 #include "base/stl_util.h"
 #include "chrome/browser/extensions/extension_message_bubble_controller.h"
 #include "chrome/browser/extensions/tab_helper.h"
@@ skipping 123 matching lines @@
 }
 
 void BrowserActionsContainer::Init() {
   LoadImages();
 
   // We wait to set the container width until now so that the chevron images
   // will be loaded.  The width calculation needs to know the chevron size.
   container_width_ = toolbar_actions_bar_->GetPreferredSize().width();
 }
 
-const std::string& BrowserActionsContainer::GetIdAt(size_t index) const {
+std::string BrowserActionsContainer::GetIdAt(size_t index) const {
   return toolbar_action_views_[index]->view_controller()->GetId();
 }
 
 ToolbarActionView* BrowserActionsContainer::GetViewForId(
     const std::string& id) {
   for (ToolbarActionView* view : toolbar_action_views_) {
     if (view->view_controller()->GetId() == id)
       return view;
   }
   return nullptr;
@@ skipping 641 matching lines @@
   warning_highlight_painter_.reset(
       views::Painter::CreateImageGridPainter(kWarningImages));
 }
 
 void BrowserActionsContainer::ClearActiveBubble(views::Widget* widget) {
   DCHECK(active_bubble_);
   DCHECK_EQ(active_bubble_->GetWidget(), widget);
   widget->RemoveObserver(this);
   active_bubble_ = nullptr;
 }