[Metal] Dispose GRBackendRenderTarget and @autoreleasepool for metal objects (#20815)

* Add @autoreleasepool to release memory

* Pass in and dispose GRBackendRenderTarget

* Use Macros

native/Avalonia.Native/src/OSX/metal.mm

@@ -88,6 +88,7 @@ public:
     }
     
     HRESULT ImportIOSurface(void *handle, AvnPixelFormat pixelFormat, IAvnMetalTexture **ppv) override {
+        START_COM_ARP_CALL;
         auto surf = (IOSurfaceRef)handle;
         auto width = IOSurfaceGetWidth(surf);
         auto height = IOSurfaceGetHeight(surf);
@@ -112,7 +113,6 @@ public:
             return E_FAIL;
         *ppv = new AvnMetalTexture(texture);
         return S_OK;
-        
     }
     
     HRESULT ImportSharedEvent(void *mtlSharedEventInstance, IAvnMTLSharedEvent**ppv) override {
@@ -132,11 +132,12 @@ public:
     
     HRESULT SignalOrWait(IAvnMTLSharedEvent *ev, uint64_t value, bool wait)
     {
+        START_ARP_CALL;
         if (@available(macOS 12.0, *))
         {
             auto e = dynamic_cast<AvnMTLSharedEvent*>(ev);
             if(e == nullptr)
-                return E_FAIL;;
+                return E_FAIL;
             auto buf = [queue commandBuffer];
             if(wait)
                 [buf encodeWaitForEvent:e->GetEvent() value:value];
@@ -204,6 +205,7 @@ public:
 
     ~AvnMetalRenderSession()
     {
+        START_ARP_CALL;
         auto buffer = [_queue commandBuffer];
         [buffer presentDrawable: _drawable];
         [buffer commit];
@@ -227,6 +229,7 @@ public:
     }
 
     HRESULT BeginDrawing(IAvnMetalRenderingSession **ret) override {
+        START_COM_ARP_CALL;
         if([NSThread isMainThread])
         {
             // Flush all existing rendering
@@ -289,7 +292,7 @@ class AvnMetalDisplay : public ComSingleObject<IAvnMetalDisplay, &IID_IAvnMetalD
 public:
     FORWARD_IUNKNOWN()
     HRESULT CreateDevice(IAvnMetalDevice **ret) override {
-
+        START_COM_ARP_CALL;
         auto device = MTLCreateSystemDefaultDevice();
         if(device == nil) {
             ret = nil;

src/Skia/Avalonia.Skia/Gpu/Metal/SkiaMetalGpu.cs

@@ -105,7 +105,7 @@ internal class SkiaMetalGpu : ISkiaGpu
                 session.IsYFlipped ? GRSurfaceOrigin.BottomLeft : GRSurfaceOrigin.TopLeft,
                 SKColorType.Bgra8888);
 
-            return new SkiaMetalRenderSession(_gpu, surface, session);
+            return new SkiaMetalRenderSession(_gpu, surface, session, backendTarget);
         }
 
         public bool IsCorrupted => false;
@@ -118,14 +118,17 @@ internal class SkiaMetalGpu : ISkiaGpu
         private readonly SkiaMetalGpu _gpu;
         private SKSurface? _surface;
         private IMetalPlatformSurfaceRenderingSession? _session;
+        private GRBackendRenderTarget? _backendTarget;
 
         public SkiaMetalRenderSession(SkiaMetalGpu gpu,
             SKSurface surface,
-            IMetalPlatformSurfaceRenderingSession session)
+            IMetalPlatformSurfaceRenderingSession session,
+            GRBackendRenderTarget backendTarget)
         {
             _gpu = gpu;
             _surface = surface;
             _session = session;
+            _backendTarget = backendTarget;
         }
 
         public void Dispose()
@@ -138,6 +141,8 @@ internal class SkiaMetalGpu : ISkiaGpu
             _surface = null;
             _session?.Dispose();
             _session = null;
+            _backendTarget?.Dispose();
+            _backendTarget = null;
         }
 
         public GRContext GrContext => _gpu._context!;