mono/MonoGame — pull request #2901 by nkast (2014-08-09 15:19:33+00:00)
Title: SwapChainRenderTarget  leak resources

This one leak windowHandle resources. ('User objects' at Task Manager).
After 10000 or so the App crash.

`SharpDX.Utilities.Dispose()` can't be used on `_swapChain`, maybe
remove `readonly` modifier?