hle: nvflinger: Add implementation for BufferSlot class.

src/core/CMakeLists.txt

@@ -540,6 +540,7 @@ add_library(core STATIC
     hle/service/nvflinger/binder.h
     hle/service/nvflinger/buffer_item.h
     hle/service/nvflinger/buffer_queue_defs.h
+    hle/service/nvflinger/buffer_slot.h
     hle/service/nvflinger/buffer_transform_flags.h
     hle/service/nvflinger/consumer_listener.h
     hle/service/nvflinger/nvflinger.cpp

src/core/hle/service/nvflinger/buffer_slot.h

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+// Copyright 2021 yuzu Emulator Project
+// Copyright 2014 The Android Open Source Project
+// Parts of this implementation were base on:
+// https://cs.android.com/android/platform/superproject/+/android-5.1.1_r38:frameworks/native/include/gui/BufferSlot.h
+
+#pragma once
+
+#include <memory>
+
+#include "common/common_types.h"
+#include "core/hle/service/nvflinger/ui/fence.h"
+
+namespace android {
+
+class GraphicBuffer;
+
+enum class BufferState : u32 {
+    Free = 0,
+    Dequeued = 1,
+    Queued = 2,
+    Acquired = 3,
+};
+
+struct BufferSlot final {
+    constexpr BufferSlot() = default;
+
+    std::shared_ptr<GraphicBuffer> graphic_buffer;
+    BufferState buffer_state{BufferState::Free};
+    bool request_buffer_called{};
+    u64 frame_number{};
+    Fence fence;
+    bool acquire_called{};
+    bool needs_cleanup_on_release{};
+    bool attached_by_consumer{};
+    bool is_preallocated{};
+};
+
+} // namespace android