extensions: Cleanup class/struct fwd declarations

extensions/browser/api/declarative_webrequest/webrequest_condition.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_H_
 #define EXTENSIONS_BROWSER_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_H_
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/linked_ptr.h"
 #include "components/url_matcher/url_matcher.h"
 #include "extensions/browser/api/declarative/declarative_rule.h"
 #include "extensions/browser/api/declarative_webrequest/webrequest_condition_attribute.h"
 #include "net/http/http_response_headers.h"
 
+namespace net {
+class URLRequest;
+}
+
 namespace extensions {
 class ExtensionNavigationUIData;
 
 // Container for information about a URLRequest to determine which
 // rules apply to the request.
 struct WebRequestData {
   WebRequestData(net::URLRequest* request, RequestStage stage);
   WebRequestData(net::URLRequest* request,
                  RequestStage stage,
                  ExtensionNavigationUIData* navigation_ui_data,
@@ skipping 82 matching lines @@
   int applicable_request_stages_;
 
   DISALLOW_COPY_AND_ASSIGN(WebRequestCondition);
 };
 
 typedef DeclarativeConditionSet<WebRequestCondition> WebRequestConditionSet;
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_H_