extensions: Cleanup class/struct fwd declarations

extensions/browser/api/declarative_webrequest/webrequest_condition_attribute.h

 // Copyright (c) 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 EXTENSIONS_BROWSER_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_ATTRIBUTE_H_
 #define EXTENSIONS_BROWSER_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_ATTRIBUTE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "content/public/common/resource_type.h"
 #include "extensions/browser/api/declarative_webrequest/request_stage.h"
 #include "extensions/common/api/events.h"
 
 namespace base {
 class Value;
 }
 
-namespace net {
-class URLRequest;
-}
-
 namespace extensions {
 
 class HeaderMatcher;
 struct WebRequestData;
 
 // Base class for all condition attributes of the declarative Web Request API
 // except for condition attribute to test URLPatterns.
 class WebRequestConditionAttribute
     : public base::RefCounted<WebRequestConditionAttribute> {
  public:
@@ skipping 226 matching lines @@
   ~WebRequestConditionAttributeStages() override;
 
   const int allowed_stages_;  // Composition of RequestStage values.
 
   DISALLOW_COPY_AND_ASSIGN(WebRequestConditionAttributeStages);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_ATTRIBUTE_H_