chrome: Cleanup class/struct forward declarations

chrome/browser/safe_browsing/incident_reporting/resource_request_detector.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 CHROME_BROWSER_SAFE_BROWSING_INCIDENT_REPORTING_RESOURCE_REQUEST_DETECTOR_H_
 #define CHROME_BROWSER_SAFE_BROWSING_INCIDENT_REPORTING_RESOURCE_REQUEST_DETECTOR_H_
 
 #include <memory>
 
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/safe_browsing/incident_reporting/incident_receiver.h"
 #include "components/safe_browsing_db/database_manager.h"
 
 namespace net {
 class URLRequest;
 }
 
 namespace safe_browsing {
 
-class SafeBrowsingService;
-
 class ClientIncidentReport_IncidentData_ResourceRequestIncident;
 
 struct ResourceRequestInfo {
   GURL url;
   content::ResourceType resource_type;
   int render_process_id;
   int render_frame_id;
 };
 
 // Observes network requests and reports suspicious activity.
@@ skipping 26 matching lines @@
   bool allow_null_profile_for_testing_;
 
   base::WeakPtrFactory<ResourceRequestDetector> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceRequestDetector);
 };
 
 }  // namespace safe_browsing
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_INCIDENT_REPORTING_RESOURCE_REQUEST_DETECTOR_H_