Proxy PPB_ArrayBuffer_Dev, make them work over Messaging

ppapi/native_client/src/shared/ppapi_proxy/browser_ppb_messaging_rpc_server.cc

Index: ppapi/native_client/src/shared/ppapi_proxy/browser_ppb_messaging_rpc_server.cc
diff --git a/ppapi/native_client/src/shared/ppapi_proxy/browser_ppb_messaging_rpc_server.cc b/ppapi/native_client/src/shared/ppapi_proxy/browser_ppb_messaging_rpc_server.cc
index d2d35e599fa76632bbbd5f05f65e7c100aff8a3e..96de74acaa732f37d2f536e187079f8e17bfcd4b 100644
--- a/ppapi/native_client/src/shared/ppapi_proxy/browser_ppb_messaging_rpc_server.cc
+++ b/ppapi/native_client/src/shared/ppapi_proxy/browser_ppb_messaging_rpc_server.cc
@@ -27,13 +27,16 @@ void PpbMessagingRpcServer::PPB_Messaging_PostMessage(
   rpc->result = NACL_SRPC_RESULT_APP_ERROR;
 
   PP_Var message;
-  if (!DeserializeTo(message_bytes, message_size, 1, &message))
+  if (!DeserializeTo(message_bytes, message_size, 1, &message)) {
+    DebugPrintf("PPB_Messaging::HandleMessage, DeserializeTo failed!\n");
     return;
+  }
 
   PPBMessagingInterface()->PostMessage(instance, message);
 
-  // In the case of a string, DeserializeTo creates a PP_Var with a reference-
-  // count of 1. We must release the var, or it will stay in the browser's map.
+  // In the case of ref-counted types, DeserializeTo creates a PP_Var with a ref
+  // erence-count of 1. We must release the var, or it will stay in the
+  // browser's map.
   PPBVarInterface()->Release(message);
 
   DebugPrintf("PPB_Messaging::PostMessage: instance=%"NACL_PRIu32"\n",