chrome: Cleanup class/struct forward declarations

chrome/browser/profiles/profile_statistics_aggregator.h

 // Copyright 2016 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_PROFILES_PROFILE_STATISTICS_AGGREGATOR_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_STATISTICS_AGGREGATOR_H_
 
 #include <stddef.h>
 
 #include <memory>
 #include <set>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "base/task_runner.h"
 #include "chrome/browser/profiles/profile_statistics_common.h"
 #include "components/bookmarks/browser/bookmark_model_observer.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/password_manager/core/browser/password_store_consumer.h"
 
-namespace bookmarks {
-class BookMarkModel;
-class BookMarkNode;
-}
-
 class Profile;
 
 class ProfileStatisticsAggregator
     : public base::RefCountedThreadSafe<ProfileStatisticsAggregator> {
   // This class is used internally by GetProfileStatistics and
   // StoreProfileStatisticsToCache.
   //
   // The class collects statistical information about the profile and returns
   // the information via a callback function. Currently bookmarks, history,
   // logins and preferences are counted.
@@ skipping 117 matching lines @@
   // Bookmark counting
   std::unique_ptr<BookmarkModelHelper> bookmark_model_helper_;
 
   // Password counting.
   PasswordStoreConsumerHelper password_store_consumer_helper_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileStatisticsAggregator);
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_STATISTICS_AGGREGATOR_H_