**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`
<div style={{width: 1, height: '2px'}} />,
        ));
      it('should error reconnecting reordered style values', () =>
        expectMarkupMismatch(
          <div style={{width: '1px', fontSize: '2px'}} />,
          <div style={{fontSize: '2px', width: '1px'}} />,
        ));
      it('can explicitly ignore errors reconnecting added style values', () =>
        expectMarkupMatch(
          <div style={{}} />,
          <div style={{width: '1px'}} suppressHydrationWarning={true} />,
        ));
      it('can explicitly ignore reconnecting different style values', () =>
        expectMarkupMatch(
          <div style={{width: '1px'}} />,
          <div style={{width: '2px'}} suppressHydrationWarning={true} />,
        ));
    });
    describe('text nodes', function() {
      it('should error reconnecting different text', () =>
        expectMarkupMismatch(<div>Text</div>, <div>Other Text</div>));
      it('should reconnect a div with a number and string version of number', () =>
        expectMarkupMatch(<div>{2}</div>, <div>2</div>));
      it('should error reconnecting different numbers', () =>
        expectMarkupMismatch(<div>{2}</div>, <div>{3}</div>));
      it('should error reconnecting different number from text', () =>
        expectMarkupMismatch(<div>{2}</div>, <div>3</div>));
      it('should error reconnecting different text in two code blocks', () =>
        expectMarkupMismatch(
          <div>{'Text1'}{'Text2'}</div>,