components: Cleanup class/struct fwd declarations

components/policy/core/browser/proxy_policy_handler.h

 // Copyright 2013 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_POLICY_CORE_BROWSER_PROXY_POLICY_HANDLER_H_
 #define COMPONENTS_POLICY_CORE_BROWSER_PROXY_POLICY_HANDLER_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "components/policy/core/browser/configuration_policy_handler.h"
 
 namespace policy {
 
-class ProxyMap;
-class ProxyErrorMap;
-
 // ConfigurationPolicyHandler for the proxy policies.
 class POLICY_EXPORT ProxyPolicyHandler : public ConfigurationPolicyHandler {
  public:
   // Constants for the "Proxy Server Mode" defined in the policies.
   // Note that these diverge from internal presentation defined in
   // ProxyPrefs::ProxyMode for legacy reasons. The following four
   // PolicyProxyModeType types were not very precise and had overlapping use
   // cases.
   enum ProxyModeType {
     // Disable Proxy, connect directly.
@@ skipping 27 matching lines @@
   bool CheckProxyModeAndServerMode(const PolicyMap& policies,
                                    PolicyErrorMap* errors,
                                    std::string* mode_value);
 
   DISALLOW_COPY_AND_ASSIGN(ProxyPolicyHandler);
 };
 
 }  // namespace policy
 
 #endif  // COMPONENTS_POLICY_CORE_BROWSER_PROXY_POLICY_HANDLER_H_