[core] Fix performance-unnecessary-value-param errors in header files

As reported by clang-tidy-8.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mbgl/tile/tile_loader_impl.hpp b/src/mbgl/tile/tile_loader_impl.hpp
index 51efbb99e9..b12b5c73fb 100644
--- a/src/mbgl/tile/tile_loader_impl.hpp
+++ b/src/mbgl/tile/tile_loader_impl.hpp
@@ -67,7 +67,7 @@ void TileLoader<T>::loadFromCache() {
     }
 
     resource.loadingMethod = Resource::LoadingMethod::CacheOnly;
-    request = fileSource->request(resource, [this](Response res) {
+    request = fileSource->request(resource, [this](const Response& res) {
         request.reset();
 
         tile.setTriedCache();
@@ -137,7 +137,7 @@ void TileLoader<T>::loadFromNetwork() {
     // Instead of using Resource::LoadingMethod::All, we're first doing a CacheOnly, and then a
     // NetworkOnly request.
     resource.loadingMethod = Resource::LoadingMethod::NetworkOnly;
-    request = fileSource->request(resource, [this](Response res) { loadedData(res); });
+    request = fileSource->request(resource, [this](const Response& res) { loadedData(res); });
 }
 
 } // namespace mbgl