[ToolbarActionViewController] Update return type of GetId().

chrome/browser/ui/toolbar/test_toolbar_action_view_controller.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 "chrome/browser/ui/toolbar/test_toolbar_action_view_controller.h"
 
 #include "base/strings/string16.h"
 #include "chrome/browser/ui/toolbar/toolbar_action_view_delegate.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/image/image_skia.h"
 
 TestToolbarActionViewController::TestToolbarActionViewController(
     const std::string& id)
     : id_(id),
       delegate_(nullptr),
       is_enabled_(true),
       wants_to_run_(false),
       disabled_click_opens_menu_(false),
       execute_action_count_(0) {
 }
 
 TestToolbarActionViewController::~TestToolbarActionViewController() {
 }
 
-const std::string& TestToolbarActionViewController::GetId() const {
+std::string TestToolbarActionViewController::GetId() const {
   return id_;
 }
 
 void TestToolbarActionViewController::SetDelegate(
     ToolbarActionViewDelegate* delegate) {
   delegate_ = delegate;
 }
 
 gfx::Image TestToolbarActionViewController::GetIcon(
     content::WebContents* web_contents,
@@ skipping 88 matching lines @@
 void TestToolbarActionViewController::SetDisabledClickOpensMenu(
     bool disabled_click_opens_menu) {
   disabled_click_opens_menu_ = disabled_click_opens_menu;
   UpdateDelegate();
 }
 
 void TestToolbarActionViewController::UpdateDelegate() {
   if (delegate_)
     delegate_->UpdateState();
 }