Make SyncBackendRegistrar aware of loaded data

chrome/browser/sync/profile_sync_service_session_unittest.cc

Index: chrome/browser/sync/profile_sync_service_session_unittest.cc
diff --git a/chrome/browser/sync/profile_sync_service_session_unittest.cc b/chrome/browser/sync/profile_sync_service_session_unittest.cc
index b7508e3a060823df218e5fe82c22e3a9d15e136f..0a68c7dbf78a2fb8c35f095ae6786c2d0ca6ceba 100644
--- a/chrome/browser/sync/profile_sync_service_session_unittest.cc
+++ b/chrome/browser/sync/profile_sync_service_session_unittest.cc
@@ -217,8 +217,9 @@ class ProfileSyncServiceSessionTest
     BrowserWithTestWindowTest::TearDown();
   }
 
-  bool StartSyncService(const base::Closure& callback,
-                        bool will_fail_association) {
+  bool StartSyncService(
+      const base::Callback<void(syncer::UserShare*)>& callback,
+      bool will_fail_association) {
     if (sync_service_.get())
       return false;
     SigninManager* signin = SigninManagerFactory::GetForProfile(profile());
@@ -282,16 +283,22 @@ class CreateRootHelper {
 
   virtual ~CreateRootHelper() {}
 
-  const base::Closure& callback() const { return callback_; }
-  bool success() { return success_; }
+  const base::Callback<void(syncer::UserShare*)>& callback() const {
+    return callback_;
+  }
+
+  bool success() {
+    return success_;
+  }
 
  private:
-  void CreateRootCallback(ProfileSyncServiceSessionTest* test) {
+  void CreateRootCallback(ProfileSyncServiceSessionTest* test,
+                          syncer::UserShare* user_share) {
     success_ = ProfileSyncServiceTestHelper::CreateRoot(
-        syncer::SESSIONS, test->sync_service()->GetUserShare(), test->ids());
+        syncer::SESSIONS, user_share, test->ids());
   }
 
-  base::Closure callback_;
+  base::Callback<void(syncer::UserShare*)> callback_;
   bool success_;
 };
 
@@ -373,7 +380,8 @@ TEST_F(ProfileSyncServiceSessionTest, DISABLED_WriteFilledSessionToNode) {
 
 // Test that we fail on a failed model association.
 TEST_F(ProfileSyncServiceSessionTest, FailModelAssociation) {
-  ASSERT_TRUE(StartSyncService(base::Closure(), true));
+  ASSERT_TRUE(StartSyncService(
+          TestProfileSyncService::NullCallback(), true));
   ASSERT_TRUE(sync_service_->HasUnrecoverableError());
 }