**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`
'a select value overriding defaultValue no matter the prop order',
        async render => {
          const e = await render(
            <select defaultValue="baz" value="bar" readOnly={true}>
              {options}
            </select>,
            1,
          );
          expectSelectValue(e, 'bar');
        },
      );
    });
    describe('user interaction', function() {
      let ControlledInput,
        ControlledTextArea,
        ControlledCheckbox,
        ControlledSelect;
      beforeEach(() => {
        ControlledInput = class extends React.Component {
          constructor() {
            super();
            this.state = {value: 'Hello'};
          }
          handleChange(event) {
            if (this.props.onChange) {
              this.props.onChange(event);
            }
            this.setState({value: event.target.value});
          }
          render() {