content: Cleanup class/struct forward declarations

content/browser/dom_storage/dom_storage_context_impl.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 CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_IMPL_H_
 #define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_IMPL_H_
 
 #include <stdint.h>
 
 #include <deque>
@@ skipping 10 matching lines @@
 #include "base/optional.h"
 #include "base/time/time.h"
 #include "base/trace_event/memory_dump_provider.h"
 #include "content/browser/bad_message.h"
 #include "content/common/content_export.h"
 #include "url/gurl.h"
 
 namespace base {
 class FilePath;
 class NullableString16;
-class Time;
 }
 
 namespace storage {
 class SpecialStoragePolicy;
 }
 
 namespace content {
 
 class DOMStorageArea;
 class DOMStorageNamespace;
@@ skipping 227 matching lines @@
   // sessionStorage.
   std::map<std::string, int64_t> persistent_namespace_id_to_namespace_id_;
 
   // For cleaning up unused databases more aggressively.
   bool is_low_end_device_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_IMPL_H_