Add missing url/gurl.h include

extensions/common/extension_urls.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 EXTENSIONS_COMMON_EXTENSION_URLS_H_
 #define EXTENSIONS_COMMON_EXTENSION_URLS_H_
 
 #include <string>
 
 #include "base/strings/string16.h"
-
-class GURL;
+#include "url/gurl.h"
 
 namespace extensions {
 
 // The name of the event_bindings module.
 extern const char kEventBindings[];
 
 // The name of the schemaUtils module.
 extern const char kSchemaUtils[];
 
 // Determine whether or not a source came from an extension. |source| can link
@@ skipping 55 matching lines @@
 // Returns whether the URL is the webstore update URL (just considering host
 // and path, not scheme, query, etc.)
 bool IsWebstoreUpdateUrl(const GURL& update_url);
 
 // Returns true if the URL points to an extension blacklist.
 bool IsBlacklistUpdateUrl(const GURL& url);
 
 }  // namespace extension_urls
 
 #endif  // EXTENSIONS_COMMON_EXTENSION_URLS_H_