components: Cleanup class/struct fwd declarations

components/pdf/renderer/pepper_pdf_host.h

 // Copyright 2014 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 COMPONENTS_PDF_RENDERER_PEPPER_PDF_HOST_H_
 #define COMPONENTS_PDF_RENDERER_PEPPER_PDF_HOST_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "ipc/ipc_platform_file.h"
 #include "ppapi/c/ppb_image_data.h"
 #include "ppapi/c/private/ppb_pdf.h"
 #include "ppapi/host/resource_host.h"
 #include "ppapi/proxy/serialized_structs.h"
 
-struct PP_ImageDataDesc;
-struct PP_Size;
-class SkBitmap;
-
 namespace content {
-class PepperPluginInstance;
 class RenderFrame;
 class RendererPpapiHost;
 }
 
 namespace ppapi {
-class HostResource;
-
 namespace host {
 struct HostMessageContext;
 }  // namespace host
 }  // namespace ppapi
 
 namespace pdf {
 
 class PdfAccessibilityTree;
 
 class PepperPDFHost : public ppapi::host::ResourceHost {
@@ skipping 67 matching lines @@
   std::unique_ptr<PdfAccessibilityTree> pdf_accessibility_tree_;
 
   content::RendererPpapiHost* const host_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperPDFHost);
 };
 
 }  // namespace pdf
 
 #endif  // COMPONENTS_PDF_RENDERER_PEPPER_PDF_HOST_H_