**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`
var {precacheFiberNode, updateFiberProps} = ReactDOMComponentTree;
if (__DEV__) {
  var SUPPRESS_HYDRATION_WARNING = 'suppressHydrationWarning';
  var lowPriorityWarning = require('lowPriorityWarning');
  var warning = require('fbjs/lib/warning');
  var validateDOMNesting = require('validateDOMNesting');
  var {updatedAncestorInfo} = validateDOMNesting;
  if (
    typeof Map !== 'function' ||
    Map.prototype == null ||
    typeof Map.prototype.forEach !== 'function' ||
    typeof Set !== 'function' ||
    Set.prototype == null ||
    typeof Set.prototype.clear !== 'function' ||
    typeof Set.prototype.forEach !== 'function'
  ) {
    warning(
      false,
      'React depends on Map and Set built-in types. Make sure that you load a ' +
        'polyfill in older browsers. http://fb.me/react-polyfills',
    );
  }
}
require('ReactDOMClientInjection');
require('ReactDOMInjection');
ReactControlledComponent.injection.injectFiberControlledHostComponent(
  ReactDOMFiberComponent,
);
type DOMContainer =
  | (Element & {