Test which verifies the basic facilities of feColorMatrix.

This test uses the following elements : a nested <svg> with a viewBox attribute, <linearGradient>, <filter>, <feColorMatrix>, <feComposite>

The test case shows five rectangles filled with a gradient showing the effects of feColorMatrix: an unfiltered rectangle acting as a reference, use of the feColorMatrix matrix option to convert to grayscale, use of the feColorMatrix saturate option, use of the feColorMatrix hueRotate option, and use of the feColorMatrix luminanceToAlpha option.

The test is somewhat self-explanatory as the strings document the type of feColorMatrix operation that is being used.