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

chrome/browser/services/gcm/fake_gcm_profile_service.h

Index: chrome/browser/services/gcm/fake_gcm_profile_service.h
diff --git a/chrome/browser/services/gcm/fake_gcm_profile_service.h b/chrome/browser/services/gcm/fake_gcm_profile_service.h
index aabba5e5aaf0b6edbfaea1d26afdb41eeda48eb9..7631a93ef1214b543a24c3191f4e90b1a02c3b04 100644
--- a/chrome/browser/services/gcm/fake_gcm_profile_service.h
+++ b/chrome/browser/services/gcm/fake_gcm_profile_service.h
@@ -10,6 +10,7 @@
 #include <vector>
 
 #include "base/macros.h"
+#include "components/gcm_driver/gcm_client.h"
 #include "components/gcm_driver/gcm_driver.h"
 #include "components/gcm_driver/gcm_profile_service.h"
 
@@ -45,7 +46,8 @@ class FakeGCMProfileService : public GCMProfileService {
   void SetUnregisterCallback(const UnregisterCallback& callback);
 
   void DispatchMessage(const std::string& app_id,
-                       const IncomingMessage& message);
+                       const IncomingMessage& message,
+                       const GCMClient::MessageReceiptCallback& callback);
 
   const OutgoingMessage& last_sent_message() const {
     return last_sent_message_;