components: Cleanup class/struct fwd declarations

components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h

 // Copyright 2014 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_HEADERS_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_HEADERS_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "base/strings/string_piece.h"
 #include "base/time/time.h"
 #include "net/proxy/proxy_service.h"
 
-class GURL;
-
 namespace net {
 
 class HttpResponseHeaders;
 
 }  // namespace net
 
 namespace data_reduction_proxy {
 
-class DataReductionProxyEventCreator;
-
 // Values of the UMA DataReductionProxy.BypassType{Primary|Fallback} and
 // DataReductionProxy.BlockType{Primary|Fallback} histograms. This enum must
 // remain synchronized with the enum of the same name in
 // metrics/histograms/histograms.xml.
 enum DataReductionProxyBypassType {
 #define BYPASS_EVENT_TYPE(label, value) BYPASS_EVENT_TYPE_ ## label = value,
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_bypass_type_list.h"
 #undef BYPASS_EVENT_TYPE
 };
 
@@ skipping 140 matching lines @@
     const net::HttpResponseHeaders* headers,
     std::string* content_length_fingerprint);
 
 // Returns values of the Chrome-Proxy header, but with its fingerprint removed.
 void GetDataReductionProxyHeaderWithFingerprintRemoved(
     const net::HttpResponseHeaders* headers,
     std::vector<std::string>* values);
 
 }  // namespace data_reduction_proxy
 #endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_HEADERS_H_