client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.DefaultRequestHeaders.TryAddWithoutValidation("Authorization", "key=" + API_KEY);
Task.WaitAll(client.PostAsync(url, new StringContent(jGcmData.ToString(), Encoding.Default, "application/json")).ContinueWith(response =>
{
Logger.Log(String.Format("Respuesta de GCM {0} - {1} - {2} - {3} - {4}", response.IsCompleted, response.AsyncState, response.Result.Version, response.Exception, jGcmData.ToString()));