chrome: Cleanup class/struct forward declarations

chrome/browser/ui/confirm_bubble_model.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 CHROME_BROWSER_UI_CONFIRM_BUBBLE_MODEL_H_
 #define CHROME_BROWSER_UI_CONFIRM_BUBBLE_MODEL_H_
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "url/gurl.h"
 
-namespace gfx {
-class Image;
-}
-
 // An interface implemented by objects wishing to control an ConfirmBubbleView.
 // To use this class to implement a bubble menu, we need two steps:
 // 1. Implement a class derived from this class.
 // 2. Call chrome::ShowConfirmBubble() with the class implemented in 1.
 class ConfirmBubbleModel {
  public:
   enum BubbleButton {
     BUTTON_NONE   = 0,
     BUTTON_OK     = 1 << 0,
     BUTTON_CANCEL = 1 << 1,
@@ skipping 31 matching lines @@
   virtual GURL GetLinkURL() const;
 
   // Called when the link is clicked.
   virtual void LinkClicked();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ConfirmBubbleModel);
 };
 
 #endif  // CHROME_BROWSER_UI_CONFIRM_BUBBLE_MODEL_H_