chrome: Cleanup class/struct forward declarations

chrome/browser/plugins/plugin_finder.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 CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_
 #define CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_
 
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/strings/string16.h"
 #include "base/synchronization/lock.h"
 #include "chrome/common/features.h"
 #include "content/public/common/webplugininfo.h"
 
 namespace base {
 class DictionaryValue;
 }
 
-class GURL;
 class PluginMetadata;
 class PrefRegistrySimple;
 
 #if BUILDFLAG(ENABLE_PLUGIN_INSTALLATION)
 class PluginInstaller;
 #endif
 
 // This class should be created and initialized by calling
 // |GetInstance()| and |Init()| on the UI thread.
 // After that it can be safely used on any other thread.
@@ skipping 55 matching lines @@
   int version_;
 
   // Synchronization for the above member variables is
   // required since multiple threads can be accessing them concurrently.
   base::Lock mutex_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginFinder);
 };
 
 #endif  // CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_