**Do you want to request a *feature* or report a *bug*?**
Bug

**What is the current behavior?**
I've started recieving this warning about my SVGs which is using [feGaussianBlur](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/feGaussianBlur): 
`Warning: Expected server HTML to contain a matching <feGaussianBlur> in <filter>.`

**What is the expected behavior?**
Should be no warnings because there are no difference.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
Such behavior started right after updating to `React 16.0.0-rc.3` and never happened with `React 15.6.1`
});
    });
    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" />);