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

sync/internal_api/public/base/model_type_payload_map.cc

Index: sync/internal_api/public/base/model_type_payload_map.cc
diff --git a/sync/internal_api/public/base/model_type_payload_map.cc b/sync/internal_api/public/base/model_type_payload_map.cc
index 04222ee30266282f4e42d36824c32793ac85501d..1728130be466f97e6a1c7a226fa50a3e997ff44f 100644
--- a/sync/internal_api/public/base/model_type_payload_map.cc
+++ b/sync/internal_api/public/base/model_type_payload_map.cc
@@ -14,11 +14,10 @@
 namespace syncer {
 
 ModelTypePayloadMap ModelTypePayloadMapFromEnumSet(
-    syncer::ModelTypeSet types,
+    ModelTypeSet types,
     const std::string& payload) {
   ModelTypePayloadMap types_with_payloads;
-  for (syncer::ModelTypeSet::Iterator it = types.First();
-       it.Good(); it.Inc()) {
+  for (ModelTypeSet::Iterator it = types.First(); it.Good(); it.Inc()) {
     types_with_payloads[it.Get()] = payload;
   }
   return types_with_payloads;
@@ -52,7 +51,7 @@ DictionaryValue* ModelTypePayloadMapToValue(
     std::string base64_marker;
     bool encoded = base::Base64Encode(it->second, &base64_marker);
     DCHECK(encoded);
-    value->SetString(syncer::ModelTypeToString(it->first), base64_marker);
+    value->SetString(ModelTypeToString(it->first), base64_marker);
   }
   return value;
 }