[Sync] Add support for proxy types

chrome/browser/sync/glue/sync_backend_host.cc

Index: chrome/browser/sync/glue/sync_backend_host.cc
diff --git a/chrome/browser/sync/glue/sync_backend_host.cc b/chrome/browser/sync/glue/sync_backend_host.cc
index 0c0aae6598bd83aa6465acee797c9997a0cf0fcc..fcb64580361a0addd34567871461787e336500a9 100644
--- a/chrome/browser/sync/glue/sync_backend_host.cc
+++ b/chrome/browser/sync/glue/sync_backend_host.cc
@@ -683,6 +683,7 @@ void SyncBackendHost::ConfigureDataTypes(
 
   syncer::ModelTypeSet types_to_download = registrar_->ConfigureDataTypes(
       types_to_add, types_to_remove);
+  types_to_download.RemoveAll(syncer::LocalTypes());

[tim (not reviewing), 2013/01/18 20:56:33]

It looks like most of this CL is actually removing virtual types from places
where they don't match the expectation of the code around it.  Are we really
sure "virtual types" aren't purely a glue/ layer translation concept that don't
need to be plumbed down to the sync engine?

[Nicolas Zea, 2013/01/19 00:03:13]

How do you mean? If we're passing information via the routing info, it has to be
understood by the engine layer.

That said, most of the places being adjusted are tests. I also think I was
prematurely adjusting some of them, and so have slimmed this patch down a bit.

   if (!types_to_download.Empty())
     types_to_download.Put(syncer::NIGORI);