AssetBundleDisposable.cs

using System;
using UnityEngine;

public class AssetBundleDisposable : IDisposable
{
    public AssetBundle AssetBundle { get; private set; }

    private bool _disposed = false;

    public AssetBundleDisposable(AssetBundle assetBundle)
    {
        AssetBundle = assetBundle;
        _disposed = false;
    }

    ~AssetBundleDisposable()
    {
        // Dispose(false);
    }

    public void Dispose()
    {
        Dispose(true);
    }

    protected virtual void Dispose(bool disposing)
    {
        if (_disposed || AssetBundle == null)
        {
            return;
        }

        AssetBundle.Unload(true);
        AssetBundle = null;
        _disposed = true;
    }
}

static class AssetBundleDisposableExtension
{
    public static AssetBundleDisposable AsDisposable(this AssetBundle assetBundle)
    {
        return new AssetBundleDisposable(assetBundle);
    }
}