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

components/gcm_driver/fake_gcm_client.h

Index: components/gcm_driver/fake_gcm_client.h
diff --git a/components/gcm_driver/fake_gcm_client.h b/components/gcm_driver/fake_gcm_client.h
index 251b0fd5b22fe49d83ff94857fae1f775510d225..ca5916d37bf3ebc920ee9e69555f73bc2d411a57 100644
--- a/components/gcm_driver/fake_gcm_client.h
+++ b/components/gcm_driver/fake_gcm_client.h
@@ -11,6 +11,7 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "components/gcm_driver/gcm_client.h"
+#include "components/gcm_driver/gcm_message_status.h"
 #include "components/gcm_driver/gcm_stats_recorder_impl.h"
 
 namespace base {
@@ -58,6 +59,9 @@ class FakeGCMClient : public GCMClient {
   void Send(const std::string& app_id,
             const std::string& receiver_id,
             const OutgoingMessage& message) override;
+  void SendMessageReceipt(const std::string& message_id,
+                          const std::string& app_id,
+                          GCMMessageStatus status) override;
   void RecordDecryptionFailure(const std::string& app_id,
                                GCMEncryptionProvider::DecryptionResult result)
       override;
@@ -87,6 +91,7 @@ class FakeGCMClient : public GCMClient {
   // Simulate receiving something from the server.
   // Called on UI thread.
   void ReceiveMessage(const std::string& app_id,
+                      const std::string& message_id,
                       const IncomingMessage& message);
   void DeleteMessages(const std::string& app_id);
 
@@ -94,6 +99,10 @@ class FakeGCMClient : public GCMClient {
     start_mode_overridding_ = overridding;
   }
 
+  const std::string& receipt_app_id() { return receipt_app_id_; }
+  const std::string& receipt_message_id() { return receipt_message_id_; }
+  GCMMessageStatus receipt_status() { return receipt_status_; }
+
  private:
   // Called on IO thread.
   void DoStart();
@@ -105,7 +114,8 @@ class FakeGCMClient : public GCMClient {
       const linked_ptr<RegistrationInfo>& registration_info);
   void SendFinished(const std::string& app_id, const OutgoingMessage& message);
   void MessageReceived(const std::string& app_id,
-                       const IncomingMessage& message);
+                       const IncomingMessage& message,
+                       const GCMClient::MessageReceiptCallback& callback);
   void MessagesDeleted(const std::string& app_id);
   void MessageSendError(const std::string& app_id,
                         const SendErrorDetails& send_error_details);
@@ -121,6 +131,9 @@ class FakeGCMClient : public GCMClient {
   scoped_refptr<base::SequencedTaskRunner> io_thread_;
   std::map<std::string, std::pair<std::string, std::string>> instance_id_data_;
   GCMStatsRecorderImpl recorder_;
+  std::string receipt_app_id_;
+  std::string receipt_message_id_;
+  GCMMessageStatus receipt_status_;
   base::WeakPtrFactory<FakeGCMClient> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeGCMClient);