metal: fix texture memory tracking

src/modules/graphics/vulkan/Texture.cpp

@@ -237,23 +237,6 @@ bool Texture::loadVolatile()
 		}
 	}
 
-	int64 memsize = 0;
-
-	if (root)
-	{
-		for (int mip = 0; mip < getMipmapCount(); mip++)
-		{
-			int w = getPixelWidth(mip);
-			int h = getPixelHeight(mip);
-			int slices = getDepth(mip) * layerCount;
-			memsize += getPixelFormatSliceSize(format, w, h) * slices;
-		}
-
-		memsize *= static_cast<int>(msaaSamples);
-	}
-
-	setGraphicsMemorySize(memsize);
-
 	if (!debugName.empty())
 	{
 		if (vgfx->getEnabledOptionalInstanceExtensions().debugInfo)
@@ -275,6 +258,8 @@ bool Texture::loadVolatile()
 		}
 	}
 
+	updateGraphicsMemorySize(true);
+
 	return true;
 }
 
@@ -301,7 +286,7 @@ void Texture::unloadVolatile()
 	textureImage = VK_NULL_HANDLE;
 	textureImageAllocation = VK_NULL_HANDLE;
 
-	setGraphicsMemorySize(0);
+	updateGraphicsMemorySize(false);
 }
 
 Texture::~Texture()