UserAgent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Steps to reproduce the problem:
Try the following test case:

https://jsfiddle.net/dffaw25h/1/

<svg width="100" height="100">
  <svg transform="rotate(45, 50,50)">
    <rect x="25" y="25" width="50" height="50" fill="#f00" />
  </svg>
</svg>

What is the expected behavior?
Rectangle is rotated 45 deg.

What went wrong?
Not rotated.

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 61.0.3163.100  Channel: n/a
OS Version: 6.1 (Windows 7, Windows Server 2008 R2)
Flash Version: 

In SVG 1.1, the "transform" attribute was not valid for <svg> elements.  However it *is* now allowed under the SVG2 spec.

The transform works if applied to an outermost <svg> element (due to the HTML layout engine), but it does not currently work for inner <svg> elements.

https://jsfiddle.net/dffaw25h/1/