gpu: Remove left-over empty class declaration

gpu/command_buffer/service/async_pixel_transfer_delegate.h

 // Copyright (c) 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 GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_DELEGATE_H_
 #define GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_DELEGATE_H_
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "gpu/command_buffer/common/buffer.h"
 #include "gpu/gpu_export.h"
 #include "ui/gl/gl_bindings.h"
 
 namespace base {
 class SharedMemory;
 }
 
 namespace gpu {
 
-class ScopedSafeSharedMemory;
-
 struct AsyncTexImage2DParams {
   GLenum target;
   GLint level;
   GLenum internal_format;
   GLsizei width;
   GLsizei height;
   GLint border;
   GLenum format;
   GLenum type;
 };
@@ skipping 74 matching lines @@
   AsyncPixelTransferDelegate();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AsyncPixelTransferDelegate);
 };
 
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_ASYNC_PIXEL_TRANSFER_DELEGATE_H_