[Sync] Move sync/{internal_api,syncable} into syncer namespace

sync/internal_api/public/user_share.h

Index: sync/internal_api/public/user_share.h
diff --git a/sync/internal_api/public/user_share.h b/sync/internal_api/public/user_share.h
index d7936a41869d5ee58129cf17523c6353c502e171..008755d4353b03c962ac09dc8ddda6d638fb04be 100644
--- a/sync/internal_api/public/user_share.h
+++ b/sync/internal_api/public/user_share.h
@@ -10,12 +10,12 @@
 
 #include "base/memory/scoped_ptr.h"
 
+namespace syncer {
+
 namespace syncable {
 class Directory;
 }
 
-namespace syncer {
-
 // A UserShare encapsulates the syncable pieces that represent an authenticated
 // user and their data (share).
 // This encompasses all pieces required to build transaction objects on the