[ToolbarActionViewController] Update return type of GetId().

chrome/browser/ui/extensions/extension_action_view_controller.h

 // Copyright 2014 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_EXTENSIONS_EXTENSION_ACTION_VIEW_CONTROLLER_H_
 #define CHROME_BROWSER_UI_EXTENSIONS_EXTENSION_ACTION_VIEW_CONTROLLER_H_
 
 #include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "chrome/browser/extensions/extension_action_icon_factory.h"
@@ skipping 30 matching lines @@
   // The different options for showing a popup.
   enum PopupShowAction { SHOW_POPUP, SHOW_POPUP_AND_INSPECT };
 
   ExtensionActionViewController(const extensions::Extension* extension,
                                 Browser* browser,
                                 ExtensionAction* extension_action,
                                 ToolbarActionsBar* toolbar_actions_bar);
   ~ExtensionActionViewController() override;
 
   // ToolbarActionViewController:
-  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;
   bool HasPopup(content::WebContents* web_contents) const override;
@@ skipping 125 matching lines @@
 
   ScopedObserver<extensions::ExtensionHost, extensions::ExtensionHostObserver>
       popup_host_observer_;
 
   base::WeakPtrFactory<ExtensionActionViewController> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionActionViewController);
 };
 
 #endif  // CHROME_BROWSER_UI_EXTENSIONS_EXTENSION_ACTION_VIEW_CONTROLLER_H_