sync: Specialize functions that fetch type root

sync/syncable/entry.cc

Index: sync/syncable/entry.cc
diff --git a/sync/syncable/entry.cc b/sync/syncable/entry.cc
index 2be2aad687fdf56dee9baf125420868446780be7..0a4a44f2b1157650cbb2b9d1cbab72aba660dfc1 100644
--- a/sync/syncable/entry.cc
+++ b/sync/syncable/entry.cc
@@ -28,8 +28,9 @@ Entry::Entry(BaseTransaction* trans, GetByClientTag, const string& tag)
   kernel_ = trans->directory()->GetEntryByClientTag(tag);
 }
 
-Entry::Entry(BaseTransaction* trans, GetByServerTag, const string& tag)
+Entry::Entry(BaseTransaction* trans, GetTypeRoot, ModelType type)
     : basetrans_(trans) {
+  const std::string& tag = ModelTypeToRootTag(type);
   kernel_ = trans->directory()->GetEntryByServerTag(tag);
 }
 
@@ -38,6 +39,11 @@ Entry::Entry(BaseTransaction* trans, GetByHandle, int64 metahandle)
   kernel_ = trans->directory()->GetEntryByHandle(metahandle);
 }
 
+Entry::Entry(BaseTransaction* trans, GetByServerTag, const string& tag)
+    : basetrans_(trans) {
+  kernel_ = trans->directory()->GetEntryByServerTag(tag);
+}
+
 Directory* Entry::dir() const {
   return basetrans_->directory();
 }