Cleanup: Remove more forward declarations in various chrome/browser directories.

chrome/browser/browsing_data_remover.h

 // Copyright (c) 2011 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_BROWSING_DATA_REMOVER_H_
 #define CHROME_BROWSER_BROWSING_DATA_REMOVER_H_
 #pragma once
 
-#include <vector>
+#include <set>
 
 #include "base/memory/ref_counted.h"
 #include "base/observer_list.h"
 #include "base/synchronization/waitable_event_watcher.h"
 #include "base/time.h"
 #include "chrome/browser/prefs/pref_member.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/cancelable_request.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "webkit/quota/quota_types.h"
 
 class ExtensionSpecialStoragePolicy;
 class IOThread;
 class PluginDataRemover;
 class Profile;
 
 namespace disk_cache {
 class Backend;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
-namespace webkit_database {
-class DatabaseTracker;
-}
-
 namespace quota {
 class QuotaManager;
 }
 
 // BrowsingDataRemover is responsible for removing data related to browsing:
 // visits in url database, downloads, cookies ...
 
 class BrowsingDataRemover : public content::NotificationObserver,
                             public base::WaitableEventWatcher::Delegate {
  public:
@@ skipping 208 matching lines @@
 
   ObserverList<Observer> observer_list_;
 
   // Used if we need to clear history.
   CancelableRequestConsumer request_consumer_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowsingDataRemover);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_REMOVER_H_