[android] a couple missing DeleteLocalRef

platform/android/src/conversion/collection.hpp

@@ -28,6 +28,7 @@ inline jni::jobject* toArrayList(JNIEnv& env, jni::jarray<T>& array) {
 inline std::vector<std::string> toVector(JNIEnv& env, jni::jarray<jni::jobject>& array) {
     std::vector<std::string> vector;
     std::size_t len = jni::GetArrayLength(env, array);
+    vector.reserve(len);
 
     for (std::size_t i = 0; i < len; i++) {
         jni::jstring* jstr = reinterpret_cast<jni::jstring*>(jni::GetObjectArrayElement(env, array, i));

platform/android/src/file_source.cpp

@@ -124,8 +124,11 @@ jni::Class<FileSource::ResourceTransformCallback> FileSource::ResourceTransformC
 std::string FileSource::ResourceTransformCallback::onURL(jni::JNIEnv& env, jni::Object<FileSource::ResourceTransformCallback> callback, int kind, std::string url_) {
     static auto method = FileSource::ResourceTransformCallback::javaClass.GetMethod<jni::String (jni::jint, jni::String)>(env, "onURL");
     auto url = jni::Make<jni::String>(env, url_);
+
     url = callback.Call(env, method, kind, url);
-    return jni::Make<std::string>(env, url);
+    auto urlStr = jni::Make<std::string>(env, url);
+    jni::DeleteLocalRef(env, url);
+    return urlStr;
 }
 
 } // namespace android

platform/android/src/map/camera_position.cpp

@@ -33,7 +33,9 @@ mbgl::CameraOptions CameraPosition::getCameraOptions(jni::JNIEnv& env, jni::Obje
     static auto tilt = CameraPosition::javaClass.GetField<jni::jdouble>(env, "tilt");
     static auto zoom = CameraPosition::javaClass.GetField<jni::jdouble>(env, "zoom");
 
-    auto center = LatLng::getLatLng(env, position.Get(env, target));
+    auto jtarget = position.Get(env, target);
+    auto center = LatLng::getLatLng(env, jtarget);
+    jni::DeleteLocalRef(env, jtarget);
 
     return mbgl::CameraOptions {
             center,

platform/android/src/map/image.cpp

@@ -16,7 +16,9 @@ mbgl::style::Image Image::getImage(jni::JNIEnv& env, jni::Object<Image> image) {
     auto width = image.Get(env, widthField);
     auto pixelRatio = image.Get(env, pixelRatioField);
     auto pixels = image.Get(env, bufferField);
-    auto name = jni::Make<std::string>(env, image.Get(env, nameField));
+    auto jName = image.Get(env, nameField);
+    auto name = jni::Make<std::string>(env, jName);
+    jni::DeleteLocalRef(env, jName);
 
     jni::NullCheck(env, &pixels);
     std::size_t size = pixels.Length(env);