PPAPI: Make blocking completion callbacks work.

webkit/plugins/ppapi/ppb_directory_reader_impl.h

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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 WEBKIT_PLUGINS_PPAPI_PPB_DIRECTORY_READER_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_DIRECTORY_READER_IMPL_H_
 
 #include <queue>
 #include <vector>
 
 #include "base/file_util_proxy.h"
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/thunk/ppb_directory_reader_api.h"
 
-struct PP_CompletionCallback;
 struct PP_DirectoryEntry_Dev;
 
 namespace webkit {
 namespace ppapi {
 
 class PPB_FileRef_Impl;
 
 class PPB_DirectoryReader_Impl
     : public ::ppapi::Resource,
       public ::ppapi::thunk::PPB_DirectoryReader_API {
  public:
   explicit PPB_DirectoryReader_Impl(PPB_FileRef_Impl* directory_ref);
   virtual ~PPB_DirectoryReader_Impl();
 
   static PP_Resource Create(PP_Resource directory_ref);
 
   // Resource overrides.
   virtual ::ppapi::thunk::PPB_DirectoryReader_API* AsPPB_DirectoryReader_API()
       OVERRIDE;
 
   // PPB_DirectoryReader_API implementation.
-  virtual int32_t GetNextEntry(PP_DirectoryEntry_Dev* entry,
-                               PP_CompletionCallback callback) OVERRIDE;
+  virtual int32_t GetNextEntry(
+      PP_DirectoryEntry_Dev* entry,
+      scoped_refptr< ::ppapi::TrackedCallback> callback) OVERRIDE;
 
   void AddNewEntries(const std::vector<base::FileUtilProxy::Entry>& entries,
                      bool has_more);
 
  private:
   bool FillUpEntry();
 
   scoped_refptr<PPB_FileRef_Impl> directory_ref_;
   std::queue<base::FileUtilProxy::Entry> entries_;
   bool has_more_;
   PP_DirectoryEntry_Dev* entry_;
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_DIRECTORY_READER_IMPL_H_