[GCM] Adding the OnSendAcknowledgement event

chrome/browser/services/gcm/push_messaging_service_impl.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/services/gcm/push_messaging_service_impl.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 114 matching lines @@
   // TODO(mvanouwerkerk): Fire push error event on the Service Worker
   // corresponding to app_id.
 }
 
 void PushMessagingServiceImpl::OnSendError(
     const std::string& app_id,
     const GCMClient::SendErrorDetails& send_error_details) {
   NOTREACHED() << "The Push API shouldn't have sent messages upstream";
 }
 
+void PushMessagingServiceImpl::OnSendAcknowledged(
+    const std::string& app_id,
+    const std::string& message_id) {
+  NOTREACHED() << "The Push API shouldn't have sent messages upstream";
+}
+
 void PushMessagingServiceImpl::Register(
     const GURL& origin,
     int64 service_worker_registration_id,
     const std::string& sender_id,
     int renderer_id,
     int render_frame_id,
     bool user_gesture,
     const content::PushMessagingService::RegisterCallback& callback) {
   if (!gcm_profile_service_->driver()) {
     NOTREACHED() << "There is no GCMDriver. Has GCMProfileService shut down?";
@@ skipping 114 matching lines @@
       sender_ids,
       base::Bind(&PushMessagingServiceImpl::DidRegister,
                  weak_factory_.GetWeakPtr(),
                  register_callback));
 }
 
 // TODO(johnme): Unregister should decrement the pref, and call
 // RemoveAppHandler if the count drops to zero.
 
 }  // namespace gcm