Add WebGPU Backend w/ Dawn Support (#3838)

include/mbgl/webgpu/tile_layer_group.hpp

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <mbgl/renderer/layer_group.hpp>
+#include <mbgl/webgpu/uniform_buffer.hpp>
+
+namespace mbgl {
+
+class PaintParameters;
+
+namespace webgpu {
+
+/**
+ * A layer group for tile-based drawables
+ */
+class TileLayerGroup : public mbgl::TileLayerGroup {
+public:
+    TileLayerGroup(int32_t layerIndex, std::size_t initialCapacity, std::string name);
+    ~TileLayerGroup() override {}
+
+    void upload(gfx::UploadPass&) override;
+    void render(RenderOrchestrator&, PaintParameters&) override;
+
+    const gfx::UniformBufferArray& getUniformBuffers() const override { return uniformBuffers; }
+    gfx::UniformBufferArray& mutableUniformBuffers() override { return uniformBuffers; }
+
+protected:
+    webgpu::UniformBufferArray uniformBuffers;
+};
+
+} // namespace webgpu
+} // namespace mbgl