content: Cleanup class/struct forward declarations

content/browser/cache_storage/cache_storage_context_impl.h

 // Copyright 2015 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 CONTENT_BROWSER_CACHE_STORAGE_CACHE_STORAGE_CONTEXT_IMPL_H_
 #define CONTENT_BROWSER_CACHE_STORAGE_CACHE_STORAGE_CONTEXT_IMPL_H_
 
 #include <memory>
 
 #include "base/files/file_path.h"
 #include "base/memory/ref_counted.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/cache_storage_context.h"
 #include "content/public/browser/cache_storage_usage_info.h"
 
 namespace base {
 class FilePath;
 class SequencedTaskRunner;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace storage {
 class QuotaManagerProxy;
-class SpecialStoragePolicy;
 }
 
 namespace content {
 
 class BrowserContext;
 class ChromeBlobStorageContext;
 class CacheStorageManager;
 
 // One instance of this exists per StoragePartition, and services multiple
 // child processes/origins. Most logic is delegated to the owned
@@ skipping 43 matching lines @@
   // Initialized in Init(); true if the user data directory is empty.
   bool is_incognito_ = false;
 
   // Only accessed on the IO thread.
   std::unique_ptr<CacheStorageManager> cache_manager_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_CACHE_STORAGE_CACHE_STORAGE_CONTEXT_IMPL_H_