Remove dependency on server generated type root folders

sync/syncable/syncable_id.cc

Index: sync/syncable/syncable_id.cc
diff --git a/sync/syncable/syncable_id.cc b/sync/syncable/syncable_id.cc
index 5cd777ff2eff81f67f70b519eda98417eecd5c60..d50f6cb914043da2f37d4afbb4e9ffcc724b0f1f 100644
--- a/sync/syncable/syncable_id.cc
+++ b/sync/syncable/syncable_id.cc
@@ -35,19 +35,23 @@ string Id::GetServerId() const {
 
 Id Id::CreateFromServerId(const string& server_id) {
   Id id;
-  if (server_id == "0")
-    id.s_ = "r";
-  else
-    id.s_ = string("s") + server_id;
+  if (!server_id.empty()) {

[Nicolas Zea, 2015/01/26 23:21:53]

This just for testing right? Or was there another reason for this?

[stanisc, 2015/01/28 07:30:06]

Once the server transition is done, most of parent ID strings in server updates
would be empty. 
Checking it everywhere this function is called would be tedious.
Checking it here seemed like a much more elegant solution.

+    if (server_id == "0")
+      id.s_ = "r";
+    else
+      id.s_ = string("s") + server_id;
+  }
   return id;
 }
 
 Id Id::CreateFromClientString(const string& local_id) {
   Id id;
-  if (local_id == "0")
-    id.s_ = "r";
-  else
-    id.s_ = string("c") + local_id;
+  if (!local_id.empty()) {
+    if (local_id == "0")
+      id.s_ = "r";
+    else
+      id.s_ = string("c") + local_id;
+  }
   return id;
 }