chrome: Cleanup class/struct forward declarations

chrome/browser/favicon/chrome_favicon_client.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_FAVICON_CHROME_FAVICON_CLIENT_H_
 #define CHROME_BROWSER_FAVICON_CHROME_FAVICON_CLIENT_H_
 
 #include "base/macros.h"
 #include "components/favicon/core/favicon_client.h"
 
 class GURL;
 class Profile;
 
-namespace bookmarks {
-class BookmarkModel;
-}
-
 // ChromeFaviconClient implements the the FaviconClient interface.
 class ChromeFaviconClient : public favicon::FaviconClient {
  public:
   explicit ChromeFaviconClient(Profile* profile);
   ~ChromeFaviconClient() override;
 
  private:
   // favicon::FaviconClient implementation:
   bool IsNativeApplicationURL(const GURL& url) override;
   base::CancelableTaskTracker::TaskId GetFaviconForNativeApplicationURL(
       const GURL& url,
       const std::vector<int>& desired_sizes_in_pixel,
       const favicon_base::FaviconResultsCallback& callback,
       base::CancelableTaskTracker* tracker) override;
 
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeFaviconClient);
 };
 
 #endif  // CHROME_BROWSER_FAVICON_CHROME_FAVICON_CLIENT_H_