Add method for identifying different InfoBars

chrome/browser/ui/startup/google_api_keys_infobar_delegate.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_STARTUP_GOOGLE_API_KEYS_INFOBAR_DELEGATE_H_
 #define CHROME_BROWSER_UI_STARTUP_GOOGLE_API_KEYS_INFOBAR_DELEGATE_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/infobars/core/confirm_infobar_delegate.h"
 #include "url/gurl.h"
 
 class InfoBarService;
 
 // An infobar that is run with a string and a "Learn More" link.
 class GoogleApiKeysInfoBarDelegate : public ConfirmInfoBarDelegate {
  public:
   // If Google API keys are missing, creates a missing Google API Keys infobar
   // and delegate and adds the infobar to |infobar_service|.
   static void Create(InfoBarService* infobar_service);
 
  private:
   GoogleApiKeysInfoBarDelegate();
   ~GoogleApiKeysInfoBarDelegate() override;
 
+  infobars::InfoBarDelegate::InfoBarIdentifier GetIdentifier() const override;
   base::string16 GetMessageText() const override;
   int GetButtons() const override;
   base::string16 GetLinkText() const override;
   GURL GetLinkURL() const override;
 
   DISALLOW_COPY_AND_ASSIGN(GoogleApiKeysInfoBarDelegate);
 };
 
 #endif  // CHROME_BROWSER_UI_STARTUP_GOOGLE_API_KEYS_INFOBAR_DELEGATE_H_