content: Cleanup class/struct forward declarations

content/public/browser/gpu_data_manager.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 CONTENT_PUBLIC_BROWSER_GPU_DATA_MANAGER_H_
 #define CONTENT_PUBLIC_BROWSER_GPU_DATA_MANAGER_H_
 
 #include <list>
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/process/process.h"
 #include "content/common/content_export.h"
 
 class GURL;
 
 namespace base {
 class FilePath;
-class ListValue;
 }
 
 namespace gpu {
 struct GPUInfo;
 }
 
 namespace content {
 
 class GpuDataManagerObserver;
 
@@ skipping 81 matching lines @@
   // the backlists decision and applying commandline switches.
   virtual void SetGpuInfo(const gpu::GPUInfo& gpu_info) = 0;
 
  protected:
   virtual ~GpuDataManager() {}
 };
 
 };  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_GPU_DATA_MANAGER_H_