[ToolbarActionViewController] Update return type of GetId().

chrome/browser/ui/toolbar/toolbar_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_TOOLBAR_TOOLBAR_ACTION_VIEW_CONTROLLER_H_
 #define CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTION_VIEW_CONTROLLER_H_
 
 #include "base/strings/string16.h"
 #include "ui/gfx/image/image.h"
 
@@ skipping 13 matching lines @@
 
 // The basic controller class for an action that is shown on the toolbar -
 // an extension action (like browser actions) or a component action (like
 // chromecast).
 class ToolbarActionViewController {
  public:
   virtual ~ToolbarActionViewController() {}
 
   // Returns the unique ID of this particular action. For extensions, this is
   // the extension id; for component actions, this is the name of the component.
-  virtual const std::string& GetId() const = 0;
+  virtual std::string GetId() const = 0;
 
   // Sets the view delegate, which can handle most of the front-end logic.
   virtual void SetDelegate(ToolbarActionViewDelegate* delegate) = 0;
 
   // Returns the icon to use for the given |web_contents| and |size|.
   virtual gfx::Image GetIcon(content::WebContents* web_contents,
                              const gfx::Size& size) = 0;
 
   // Returns the name of the action, which can be separate from the accessible
   // name or name for the tooltip.
@@ skipping 49 matching lines @@
   // context menu.
   virtual bool DisabledClickOpensMenu() const = 0;
 
   // Registers an accelerator. Called when the view is added to the hierarchy.
   // Unregistering any commands is the responsibility of the controller.
   virtual void RegisterCommand() {
   }
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_TOOLBAR_ACTION_VIEW_CONTROLLER_H_