components: Cleanup class/struct fwd declarations

components/data_reduction_proxy/core/common/data_reduction_proxy_event_creator.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 COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_EVENT_CREATOR_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_EVENT_CREATOR_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_event_storage_delegate.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "net/log/net_log_event_type.h"
 #include "net/log/net_log_parameters_callback.h"
 
 class GURL;
 
 namespace base {
 class TimeDelta;
-class Value;
 }
 
 namespace net {
 class NetLogWithSource;
 class ProxyServer;
 class NetLog;
 }
 
 namespace data_reduction_proxy {
 
@@ skipping 117 matching lines @@
   DataReductionProxyEventStorageDelegate* storage_delegate_;
 
   // Enforce usage on the IO thread.
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyEventCreator);
 };
 
 }  // namespace data_reduction_proxy
 #endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_EVENT_CREATOR_H_