hle: nvflinger: Add IConsumerListener interface.

src/core/CMakeLists.txt

@@ -538,6 +538,7 @@ add_library(core STATIC
     hle/service/nvflinger/buffer_queue.cpp
     hle/service/nvflinger/buffer_queue.h
     hle/service/nvflinger/buffer_transform_flags.h
+    hle/service/nvflinger/consumer_listener.h
     hle/service/nvflinger/nvflinger.cpp
     hle/service/nvflinger/nvflinger.h
     hle/service/nvflinger/pixel_format.h

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

@@ -0,0 +1,26 @@
+// 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/IConsumerListener.h
+
+#pragma once
+
+namespace android {
+
+class BufferItem;
+
+/// ConsumerListener is the interface through which the BufferQueue notifies the consumer of events
+/// that the consumer may wish to react to.
+class IConsumerListener {
+public:
+    IConsumerListener() = default;
+    virtual ~IConsumerListener() = default;
+
+    virtual void OnFrameAvailable(const BufferItem& item) = 0;
+    virtual void OnFrameReplaced(const BufferItem& item) = 0;
+    virtual void OnBuffersReleased() = 0;
+    virtual void OnSidebandStreamChanged() = 0;
+};
+
+}; // namespace android