chrome: Cleanup class/struct forward declarations

chrome/browser/ui/cocoa/autofill/password_generation_popup_view_cocoa.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_COCOA_AUTOFILL_PASSWORD_GENERATION_POPUP_VIEW_COCOA_H_
 #define CHROME_BROWSER_UI_COCOA_AUTOFILL_PASSWORD_GENERATION_POPUP_VIEW_COCOA_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
 #include "chrome/browser/ui/autofill/password_generation_popup_controller.h"
 #import "chrome/browser/ui/cocoa/autofill/autofill_popup_base_view_cocoa.h"
 #import "ui/base/cocoa/tracking_area.h"
 
-namespace autofill {
-class AutofillPopupController;
-}  // namespace autofill
-
 @class HyperlinkTextView;
 
 // Draws the native password generation popup view on Mac.
 @interface PasswordGenerationPopupViewCocoa
     : AutofillPopupBaseViewCocoa <NSTextViewDelegate> {
  @private
   // The cross-platform controller for this view.
   autofill::PasswordGenerationPopupController* controller_;  // weak
 
   base::scoped_nsobject<NSView> passwordSection_;
@@ skipping 17 matching lines @@
 // Informs the view that its controller has been (or will imminently be)
 // destroyed.
 - (void)controllerDestroyed;
 
 // The preferred size for the popup.
 - (NSSize)preferredSize;
 
 @end
 
 #endif  // CHROME_BROWSER_UI_COCOA_AUTOFILL_PASSWORD_GENERATION_POPUP_VIEW_COCOA_H_