[Sync] Remove unneeded 'using syncer::' lines and 'syncer::' scopings

sync/internal_api/public/sessions/sync_source_info.h

Index: sync/internal_api/public/sessions/sync_source_info.h
diff --git a/sync/internal_api/public/sessions/sync_source_info.h b/sync/internal_api/public/sessions/sync_source_info.h
index 4e5b26458c2d028edfa172ae3d69e13926119084..390bdb5b7114291638127e6988145f6be05a051a 100644
--- a/sync/internal_api/public/sessions/sync_source_info.h
+++ b/sync/internal_api/public/sessions/sync_source_info.h
@@ -22,17 +22,17 @@ namespace sessions {
 // specific payloads which should be sent to the server.
 struct SyncSourceInfo {
   SyncSourceInfo();
-  explicit SyncSourceInfo(const syncer::ModelTypePayloadMap& t);
+  explicit SyncSourceInfo(const ModelTypePayloadMap& t);
   SyncSourceInfo(
       const sync_pb::GetUpdatesCallerInfo::GetUpdatesSource& u,
-      const syncer::ModelTypePayloadMap& t);
+      const ModelTypePayloadMap& t);
   ~SyncSourceInfo();
 
   // Caller takes ownership of the returned dictionary.
   base::DictionaryValue* ToValue() const;
 
   sync_pb::GetUpdatesCallerInfo::GetUpdatesSource updates_source;
-  syncer::ModelTypePayloadMap types;
+  ModelTypePayloadMap types;
 };
 
 }  // namespace sessions