[ToolbarActionViewController] Update return type of GetId().

chrome/browser/ui/toolbar/media_router_action.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 #define CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 
 #include "chrome/browser/media/router/issues_observer.h"
 #include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/ui/toolbar/media_router_contextual_menu.h"
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 
 class Browser;
 class MediaRouterActionPlatformDelegate;
 
 namespace media_router {
 class MediaRouterDialogController;
 }  // namespace media_router
 
 // The class for the Media Router component action that will be shown in
 // the toolbar.
 class MediaRouterAction : public ToolbarActionViewController,
                           public media_router::IssuesObserver,
                           public media_router::MediaRoutesObserver {
  public:
   explicit MediaRouterAction(Browser* browser);
   ~MediaRouterAction() override;
 
   // ToolbarActionViewController implementation.
-  const std::string& GetId() const override;
+  std::string GetId() const override;
   void SetDelegate(ToolbarActionViewDelegate* delegate) override;
   gfx::Image GetIcon(content::WebContents* web_contents,
                      const gfx::Size& size) override;
   base::string16 GetActionName() const override;
   base::string16 GetAccessibleName(content::WebContents* web_contents)
       const override;
   base::string16 GetTooltip(content::WebContents* web_contents)
       const override;
   bool IsEnabled(content::WebContents* web_contents) const override;
   bool WantsToRun(content::WebContents* web_contents) const override;
@@ skipping 56 matching lines @@
 
   // The delegate to handle platform-specific implementations.
   scoped_ptr<MediaRouterActionPlatformDelegate> platform_delegate_;
 
   MediaRouterContextualMenu contextual_menu_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterAction);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_