Keep track of which attachments are referenced by which sync entries.

sync/syncable/directory_unittest.h

Index: sync/syncable/directory_unittest.h
diff --git a/sync/syncable/directory_unittest.h b/sync/syncable/directory_unittest.h
index 14e1a998eee96e700208555874e0a374bba73c7e..81e388823a4517f8660c57a5cb9fb8b056a0ef22 100644
--- a/sync/syncable/directory_unittest.h
+++ b/sync/syncable/directory_unittest.h
@@ -31,7 +31,6 @@ class BaseTransaction;
 //
 // Serves as base class for several other test fixtures.
 class SyncableDirectoryTest : public testing::Test {
- private:
  protected:
   static const char kDirectoryName[];
 
@@ -47,12 +46,24 @@ class SyncableDirectoryTest : public testing::Test {
   DirOpenResult ReopenDirectory();
 
   // Creates an empty entry and sets the ID field to a default one.
-  void CreateEntry(const std::string& entryname);
+  void CreateEntry(const ModelType& model_type, const std::string& entryname);
 
   // Creates an empty entry and sets the ID field to id.
-  void CreateEntry(const std::string& entryname, const int id);
+  void CreateEntry(const ModelType& model_type,
+                   const std::string& entryname,
+                   const int id);
+
+  void CreateEntry(const ModelType& model_type,
+                   const std::string& entryname,
+                   const Id& id);
+
+  void CreateEntryWithAttachmentMetadata(
+      const ModelType& model_type,
+      const std::string& entryname,
+      const Id& id,
+      const sync_pb::AttachmentMetadata& attachment_metadata);
 
-  void CreateEntry(const std::string& entryname, Id id);
+  void DeleteEntry(const Id& id);
 
   // When a directory is saved then loaded from disk, it will pass through
   // DropDeletedEntries().  This will remove some entries from the directory.