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

chrome/browser/gcm/fake_gcm_profile_service.cc

Index: chrome/browser/gcm/fake_gcm_profile_service.cc
diff --git a/chrome/browser/gcm/fake_gcm_profile_service.cc b/chrome/browser/gcm/fake_gcm_profile_service.cc
index 58c18f05392696dbaca6d96eeb315718e8a2205e..813e29ba7d2dd54f482ab825ebb687cf0483b1e3 100644
--- a/chrome/browser/gcm/fake_gcm_profile_service.cc
+++ b/chrome/browser/gcm/fake_gcm_profile_service.cc
@@ -37,8 +37,10 @@ class FakeGCMProfileService::CustomFakeGCMDriver
                       const std::string& message_id,
                       GCMClient::Result result);
 
-  void OnDispatchMessage(const std::string& app_id,
-                         const IncomingMessage& message);
+  void OnDispatchMessage(
+      const std::string& app_id,
+      const IncomingMessage& message,
+      const MessageReceiptCallback& optional_receipt_callback);
 
  protected:
   // FakeGCMDriver overrides:
@@ -192,8 +194,9 @@ void FakeGCMProfileService::CustomFakeGCMDriver::DeleteToken(
 
 void FakeGCMProfileService::CustomFakeGCMDriver::OnDispatchMessage(
     const std::string& app_id,
-    const IncomingMessage& message) {
-  DispatchMessage(app_id, message);
+    const IncomingMessage& message,
+    const MessageReceiptCallback& optional_receipt_callback) {
+  DispatchMessage(app_id, message, optional_receipt_callback);
 }
 
 // static
@@ -215,11 +218,13 @@ void FakeGCMProfileService::AddExpectedUnregisterResponse(
   unregister_responses_.push_back(result);
 }
 
-void FakeGCMProfileService::DispatchMessage(const std::string& app_id,
-                                            const IncomingMessage& message) {
+void FakeGCMProfileService::DispatchMessage(
+    const std::string& app_id,
+    const IncomingMessage& message,
+    const MessageReceiptCallback& optional_receipt_callback) {
   CustomFakeGCMDriver* custom_driver =
       static_cast<CustomFakeGCMDriver*>(driver());
-  custom_driver->OnDispatchMessage(app_id, message);
+  custom_driver->OnDispatchMessage(app_id, message, optional_receipt_callback);
 }
 
 }  // namespace gcm