Provide a mechanism for the GCM driver to send message receipts to GCM.

components/gcm_driver/gcm_driver.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 "components/gcm_driver/gcm_driver.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 260 matching lines @@
 bool GCMDriver::HasRegisterCallback(const std::string& app_id) {
   return register_callbacks_.find(app_id) != register_callbacks_.end();
 }
 
 void GCMDriver::ClearCallbacks() {
   register_callbacks_.clear();
   unregister_callbacks_.clear();
   send_callbacks_.clear();
 }
 
-void GCMDriver::DispatchMessage(const std::string& app_id,
-                                const IncomingMessage& message) {
+void GCMDriver::DispatchMessage(
+    const std::string& app_id,
+    const IncomingMessage& message,
+    const MessageReceiptCallback& optional_receipt_callback) {
   encryption_provider_.DecryptMessage(
       app_id, message, base::Bind(&GCMDriver::DispatchMessageInternal,
-                                  weak_ptr_factory_.GetWeakPtr(), app_id));
+                                  weak_ptr_factory_.GetWeakPtr(), app_id,
+                                  optional_receipt_callback));
 }
 
 void GCMDriver::DispatchMessageInternal(
     const std::string& app_id,
+    const MessageReceiptCallback& optional_receipt_callback,
     GCMEncryptionProvider::DecryptionResult result,
     const IncomingMessage& message) {
   UMA_HISTOGRAM_ENUMERATION("GCM.Crypto.DecryptMessageResult", result,
                             GCMEncryptionProvider::DECRYPTION_RESULT_LAST + 1);
 
   switch (result) {
     case GCMEncryptionProvider::DECRYPTION_RESULT_UNENCRYPTED:
     case GCMEncryptionProvider::DECRYPTION_RESULT_DECRYPTED:
+      // TODO(beverloo): When the DefaultAppHandler is gone, call
+      // SendMessageReceipt here if there isn't a valid app handler.
       GetAppHandler(app_id)->OnMessage(app_id, message);
       return;
     case GCMEncryptionProvider::DECRYPTION_RESULT_INVALID_ENCRYPTION_HEADER:
     case GCMEncryptionProvider::DECRYPTION_RESULT_INVALID_CRYPTO_KEY_HEADER:
     case GCMEncryptionProvider::DECRYPTION_RESULT_NO_KEYS:
     case GCMEncryptionProvider::DECRYPTION_RESULT_INVALID_SHARED_SECRET:
     case GCMEncryptionProvider::DECRYPTION_RESULT_INVALID_PAYLOAD:
+      optional_receipt_callback.Run(GCMMessageStatus::GCM_DECRYPTION_FAILURE);
       RecordDecryptionFailure(app_id, result);
       return;
   }
 
   NOTREACHED();
 }
 
 void GCMDriver::RegisterAfterUnregister(
     const std::string& app_id,
     const std::vector<std::string>& normalized_sender_ids,
     const UnregisterCallback& unregister_callback,
     GCMClient::Result result) {
   // Invoke the original unregister callback.
   unregister_callback.Run(result);
 
   // Trigger the pending registration.
   DCHECK(register_callbacks_.find(app_id) != register_callbacks_.end());
   RegisterImpl(app_id, normalized_sender_ids);
 }
 
 }  // namespace gcm