PPAPI: Make blocking completion callbacks work.

ppapi/thunk/ppb_transport_api.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 PPAPI_THUNK_PPB_TRANSPORT_API_H_
 #define PPAPI_THUNK_PPB_TRANSPORT_API_H_
 
+#include "base/memory/ref_counted.h"
 #include "ppapi/c/dev/ppb_transport_dev.h"
 
 namespace ppapi {
+
+class TrackedCallback;
+
 namespace thunk {
 
 class PPB_Transport_API {
  public:
   virtual ~PPB_Transport_API() {}
 
   virtual PP_Bool IsWritable() = 0;
   virtual int32_t SetProperty(PP_TransportProperty property, PP_Var value) = 0;
-  virtual int32_t Connect(PP_CompletionCallback callback) = 0;
+  virtual int32_t Connect(scoped_refptr<TrackedCallback> callback) = 0;
   virtual int32_t GetNextAddress(PP_Var* address,
-                                 PP_CompletionCallback callback) = 0;
+                                 scoped_refptr<TrackedCallback> callback) = 0;
   virtual int32_t ReceiveRemoteAddress(PP_Var address) = 0;
   virtual int32_t Recv(void* data, uint32_t len,
-                       PP_CompletionCallback callback) = 0;
+                       scoped_refptr<TrackedCallback> callback) = 0;
   virtual int32_t Send(const void* data, uint32_t len,
-                       PP_CompletionCallback callback) = 0;
+                       scoped_refptr<TrackedCallback> callback) = 0;
   virtual int32_t Close() = 0;
 };
 
 }  // namespace thunk
 }  // namespace ppapi
 
 #endif  // PPAPI_THUNK_PPB_TRANSPORT_API_H_