See the original report in https://github.com/facebook/react/issues/10772#issuecomment-333242375.

The problem is that SVG is case sensitive, and so naïvely setting `tabIndex` and relying on insensitivity won't work with it.

The good news is it seems like `tabindex` is the only valid [SVG attribute](https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute) with this problem. We just missed it because it applies both to HTML and SVG.

I think the fix is to add it back to the whitelist. 
});
    });
    describe('htmlFor property', function() {
      itRenders('htmlFor with string value', async render => {
        const e = await render(<div htmlFor="myFor" />);
        expect(e.getAttribute('for')).toBe('myFor');
      });
      itRenders('no badly cased htmlfor', async render => {
        const e = await render(<div htmlfor="myFor" />, 1);
        expect(e.hasAttribute('for')).toBe(false);
        expect(e.getAttribute('htmlfor')).toBe('myFor');
      });
      itRenders('htmlFor with an empty string', async render => {
        const e = await render(<div htmlFor="" />);
        expect(e.getAttribute('for')).toBe('');
      });
      itRenders('no htmlFor prop with true value', async render => {
        const e = await render(<div htmlFor={true} />, 1);
        expect(e.hasAttribute('for')).toBe(false);
      });
      itRenders('no htmlFor prop with false value', async render => {
        const e = await render(<div htmlFor={false} />, 1);
        expect(e.hasAttribute('for')).toBe(false);
      });
      itRenders('no htmlFor prop with null value', async render => {
        const e = await render(<div htmlFor={null} />);
        expect(e.hasAttribute('htmlFor')).toBe(false);
      });
      itRenders('htmlFor attribute on custom elements', async render => {
        const e = await render(<div is="custom-element" htmlFor="test" />);