components: Cleanup class/struct fwd declarations

components/content_settings/core/browser/cookie_settings.h

 // Copyright (c) 2012 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 COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_COOKIE_SETTINGS_H_
 #define COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_COOKIE_SETTINGS_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/keyed_service/core/refcounted_keyed_service.h"
 #include "components/prefs/pref_change_registrar.h"
 
-class ContentSettingsPattern;
 class GURL;
 class PrefService;
 
 namespace content_settings {
 
 // A frontend to the cookie settings of |HostContentSettingsMap|. Handles
 // cookie-specific logic such as blocking third-party cookies. Written on the UI
 // thread and read on any thread.
 class CookieSettings : public RefcountedKeyedService {
  public:
@@ skipping 92 matching lines @@
   mutable base::Lock lock_;
 
   bool block_third_party_cookies_;
 
   DISALLOW_COPY_AND_ASSIGN(CookieSettings);
 };
 
 }  // namespace content_settings
 
 #endif  // COMPONENTS_CONTENT_SETTINGS_CORE_BROWSER_COOKIE_SETTINGS_H_