Started on Resource class.

src/shared/ppapi_proxy/plugin_audio.cc

 /*
  * Copyright 2010 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can
  * be found in the LICENSE file.
  */
 
 #include "native_client/src/shared/ppapi_proxy/plugin_audio.h"
 
 #include <stdio.h>
 #include <string.h>
@@ skipping 11 matching lines @@
                    PP_Resource config,
                    PPB_Audio_Callback audio_callback,
                    void* user_data) {
   UNREFERENCED_PARAMETER(instance);
   UNREFERENCED_PARAMETER(config);
   UNREFERENCED_PARAMETER(audio_callback);
   UNREFERENCED_PARAMETER(user_data);
   return kInvalidResourceId;
 }
 
-PP_Bool IsAudio(PP_Resource audio) {
-  UNREFERENCED_PARAMETER(audio);
-  return PP_FALSE;
+PP_Bool IsAudio(PP_Resource resource) {
+  return PluginResource::GetAs<PluginAudio>(resource).get()
+      ? PP_TRUE : PP_FALSE;
 }
 
 PP_Resource GetCurrentConfig(PP_Resource audio) {
   UNREFERENCED_PARAMETER(audio);
   return kInvalidResourceId;
 }
 
 PP_Bool StartPlayback(PP_Resource audio) {
   UNREFERENCED_PARAMETER(audio);
   return PP_FALSE;
@@ skipping 10 matching lines @@
     Create,
     IsAudio,
     GetCurrentConfig,
     StartPlayback,
     StopPlayback,
   };
   return &intf;
 }
 
 }  // namespace ppapi_proxy