chrome: Cleanup class/struct forward declarations

chrome/browser/extensions/standard_management_policy_provider.h

 // Copyright 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 CHROME_BROWSER_EXTENSIONS_STANDARD_MANAGEMENT_POLICY_PROVIDER_H_
 #define CHROME_BROWSER_EXTENSIONS_STANDARD_MANAGEMENT_POLICY_PROVIDER_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
 #include "extensions/browser/management_policy.h"
 
 namespace extensions {
 
-class Blacklist;
 class Extension;
 class ExtensionManagement;
 
 // The standard management policy provider, which takes into account the
 // extension black/whitelists and admin black/whitelists.
 class StandardManagementPolicyProvider : public ManagementPolicy::Provider {
  public:
   explicit StandardManagementPolicyProvider(
       const ExtensionManagement* settings);
 
@@ skipping 13 matching lines @@
   bool MustRemainInstalled(const Extension* extension,
                            base::string16* error) const override;
 
  private:
   const ExtensionManagement* settings_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_STANDARD_MANAGEMENT_POLICY_PROVIDER_H_