[Sync] Eliminate friends from Directory by exposing kernel via accessor

sync/syncable/syncable_unittest.cc

Index: sync/syncable/syncable_unittest.cc
diff --git a/sync/syncable/syncable_unittest.cc b/sync/syncable/syncable_unittest.cc
index d1c6ae86d187bc90afeb8003ed108f92c9d756a4..f7d85ccc19f9ea0ca8e86c60f79fd564439d81bd 100644
--- a/sync/syncable/syncable_unittest.cc
+++ b/sync/syncable/syncable_unittest.cc
@@ -561,17 +561,15 @@ TEST_F(SyncableDirectoryManagement, TestFileRelease) {
   base::FilePath path =
       temp_dir_.path().Append(Directory::kSyncDatabaseFilename);
 
-  Directory dir(new OnDiskDirectoryBackingStore("ScopeTest", path),
-                &handler_,
-                NULL,
-                NULL,
-                NULL);
-  DirOpenResult result =
-      dir.Open("ScopeTest", &delegate_, NullTransactionObserver());
-  ASSERT_EQ(result, OPENED);
-  dir.Close();
-
-  // Closing the directory should have released the backing database file.
+  {
+    Directory dir(new OnDiskDirectoryBackingStore("ScopeTest", path), &handler_,
+                  NULL, NULL, NULL);
+    DirOpenResult result =
+        dir.Open("ScopeTest", &delegate_, NullTransactionObserver());
+    ASSERT_EQ(result, OPENED);
+  }
+
+  // Destroying the directory should have released the backing database file.
   ASSERT_TRUE(base::DeleteFile(path, true));
 }