A special render target that can be used to utilize multi-sampled renderbuffers.
[page:Float width] - The width of the render target.
[page:Float height] - The height of the render target.
[page:Object options] - (optional) object that holds texture parameters for an auto-generated target
texture and depthBuffer/stencilBuffer booleans.
Specifies the number of samples to be used for the renderbuffer storage. However, the maximum supported size for multisampling is platform dependent and defined via *gl.MAX_SAMPLES*.
[page:WebGLRenderTarget WebGLRenderTarget] properties are available on this class.
[page:WebGLRenderTarget WebGLRenderTarget] methods are available on this class.