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

sync/internal_api/syncapi_internal.h

Index: sync/internal_api/syncapi_internal.h
diff --git a/sync/internal_api/syncapi_internal.h b/sync/internal_api/syncapi_internal.h
index afc9c0a09cb77839d83507516b7160d72a02e1f0..19932e81b1349b50c686c8973148d641a5d77f36 100644
--- a/sync/internal_api/syncapi_internal.h
+++ b/sync/internal_api/syncapi_internal.h
@@ -21,14 +21,14 @@ class Cryptographer;
 
 sync_pb::PasswordSpecificsData* DecryptPasswordSpecifics(
     const sync_pb::EntitySpecifics& specifics,
-    syncer::Cryptographer* crypto);
+    Cryptographer* crypto);
 
 void SyncAPINameToServerName(const std::string& syncer_name,
                              std::string* out);
 
 bool IsNameServerIllegalAfterTrimming(const std::string& name);
 
-bool AreSpecificsEqual(const syncer::Cryptographer* cryptographer,
+bool AreSpecificsEqual(const Cryptographer* cryptographer,
                        const sync_pb::EntitySpecifics& left,
                        const sync_pb::EntitySpecifics& right);
 }  // namespace syncer