**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`
render() {
              return {x: 123};
            }
          }
          await render(<ObjectComponent />, 1);
        },
        'Objects are not valid as a React child (found: object with keys ' +
          '{x}). If you meant to render a collection of children, use ' +
          'an array instead.',
      );
      itThrowsWhenRendering(
        'top-level object',
        async render => {
          await render({x: 123});
        },
        'Objects are not valid as a React child (found: object with keys ' +
          '{x}). If you meant to render a collection of children, use ' +
          'an array instead.',
      );
    });
  });
  describe('form controls', function() {
    describe('inputs', function() {
      itRenders('an input with a value and an onChange', async render => {
        const e = await render(<input value="foo" onChange={() => {}} />);
        expect(e.value).toBe('foo');
      });