chrome: Cleanup class/struct forward declarations

chrome/browser/android/bookmarks/partner_bookmarks_shim.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_ANDROID_BOOKMARKS_PARTNER_BOOKMARKS_SHIM_H_
 #define CHROME_BROWSER_ANDROID_BOOKMARKS_PARTNER_BOOKMARKS_SHIM_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/android/jni_weak_ref.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "base/supports_user_data.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "url/gurl.h"
 
 class PrefService;
 
 namespace content {
 class BrowserContext;
-class WebContents;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 // A shim that lives on top of a BookmarkModel that allows the injection of
 // partner bookmarks without submitting changes to the bookmark model.
 // The shim persists bookmark renames/deletions in a user profile and could be
 // queried via shim->GetTitle(node) and shim->IsReachable(node).
@@ skipping 105 matching lines @@
   PrefService* prefs_;
   NodeRenamingMap node_rename_remove_map_;
 
   // The observers.
   base::ObserverList<Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(PartnerBookmarksShim);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_BOOKMARKS_PARTNER_BOOKMARKS_SHIM_H_