components: Cleanup class/struct fwd declarations

components/infobars/core/confirm_infobar_delegate.h

 // Copyright (c) 2012 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 COMPONENTS_INFOBARS_CORE_CONFIRM_INFOBAR_DELEGATE_H_
 #define COMPONENTS_INFOBARS_CORE_CONFIRM_INFOBAR_DELEGATE_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/infobars/core/infobar_delegate.h"
 #include "components/infobars/core/infobar_manager.h"
 #include "url/gurl.h"
 
 namespace infobars {
 class InfoBar;
-class InfoBarManager;
 }
 
 // An interface derived from InfoBarDelegate implemented by objects wishing to
 // control a ConfirmInfoBar.
 class ConfirmInfoBarDelegate : public infobars::InfoBarDelegate {
  public:
   enum InfoBarButton {
     BUTTON_NONE   = 0,
     BUTTON_OK     = 1 << 0,
     BUTTON_CANCEL = 1 << 1,
@@ skipping 50 matching lines @@
 
  private:
   // InfoBarDelegate:
   bool EqualsDelegate(infobars::InfoBarDelegate* delegate) const override;
   ConfirmInfoBarDelegate* AsConfirmInfoBarDelegate() override;
 
   DISALLOW_COPY_AND_ASSIGN(ConfirmInfoBarDelegate);
 };
 
 #endif  // COMPONENTS_INFOBARS_CORE_CONFIRM_INFOBAR_DELEGATE_H_