content: Cleanup class/struct forward declarations

content/renderer/gpu/stream_texture_host_android.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_RENDERER_GPU_STREAM_TEXTURE_HOST_ANDROID_H_
 #define CONTENT_RENDERER_GPU_STREAM_TEXTURE_HOST_ANDROID_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "gpu/ipc/common/android/surface_texture_peer.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_message.h"
 
 namespace base {
 class UnguessableToken;
 }
 
 namespace gfx {
 class Size;
 }
 
 namespace gpu {
 class GpuChannelHost;
 }
 
-struct GpuStreamTextureMsg_MatrixChanged_Params;
-
 namespace content {
 
 // Class for handling all the IPC messages between the GPU process and
 // StreamTextureProxy.
 class StreamTextureHost : public IPC::Listener {
  public:
   explicit StreamTextureHost(scoped_refptr<gpu::GpuChannelHost> channel,
                              int32_t route_id);
   ~StreamTextureHost() override;
 
@@ skipping 24 matching lines @@
   Listener* listener_;
   scoped_refptr<gpu::GpuChannelHost> channel_;
   base::WeakPtrFactory<StreamTextureHost> weak_ptr_factory_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(StreamTextureHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_GPU_STREAM_TEXTURE_HOST_ANDROID_H_