content: Cleanup class/struct forward declarations

content/browser/renderer_host/media/video_capture_gpu_jpeg_decoder.h

 // Copyright 2015 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_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_GPU_JPEG_DECODER_H_
 #define CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_GPU_JPEG_DECODER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 #include "content/common/content_export.h"
 #include "media/capture/video/video_capture_jpeg_decoder.h"
 #include "media/video/jpeg_decode_accelerator.h"
 
 namespace gpu {
 class GpuChannelHost;
 }
 
-namespace media {
-class VideoFrame;
-}
-
 namespace content {
 
 // Adapter to GpuJpegDecodeAccelerator for VideoCaptureDevice::Client. It takes
 // care of GpuJpegDecodeAccelerator creation, shared memory, and threading
 // issues.
 //
 // All public methods except JpegDecodeAccelerator::Client ones should be called
 // on the same thread. JpegDecodeAccelerator::Client methods should be called on
 // the IO thread.
 class CONTENT_EXPORT VideoCaptureGpuJpegDecoder
@@ skipping 71 matching lines @@
   std::unique_ptr<base::SharedMemory> in_shared_memory_;
 
   STATUS decoder_status_;
 
   DISALLOW_COPY_AND_ASSIGN(VideoCaptureGpuJpegDecoder);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_VIDEO_CAPTURE_GPU_JPEG_DECODER_H_