title: style not applied to SVGIcon in MaterialUI React
body: <p>I have a style that I am applying to ActionSearch icon but unfortunately it does not get passed through. </p>
  
  <p>Not sure what I could write more for the question, I think it's pretty simple but while Paper gets styles, the icon component doesn't.</p>
  
  <p>Any idea why this would be the case?</p>
  
  <pre><code>import React from 'react';
  import Paper from 'material-ui/Paper';
  import TextField from 'material-ui/TextField';
  import IconButton from 'material-ui/IconButton';
  import ActionSearch from 'material-ui/svg-icons/action/search';
  
  const stylePaper = {
    width: 400,
    margin: '40px auto',
    paddingBottom: 10,
    textAlign: 'center',
    display: 'inline-block'
  };
  
  const styleIcon = {
    position: 'absolute',
    top: 20
  };
  
  export default class Home extends React.Component {
    constructor(props) {
      super(props);
      this.state = {value: ''};
  
      this.handleChange = this.handleChange.bind(this);
      this.handleSubmit = this.handleSubmit.bind(this);
    }
  
    handleChange(event) {
      this.setState({value: event.target.value});
    }
  
    handleSubmit(event) {
      alert('A name was submitted: ' + this.state.value);
      event.preventDefault();
    }
  
    render() {
      return (
        &lt;form onSubmit={this.handleSubmit}&gt;
          &lt;Paper zDepth={2} style={stylePaper} &gt;
            &lt;TextField
              hintText="Type in brand, position or industry"
            /&gt;
            &lt;IconButton&gt;
              &lt;ActionSearch style={styleIcon} /&gt;
            &lt;/IconButton&gt;
          &lt;/Paper&gt;
        &lt;/form&gt;
      );
    }
  }
  </code></pre>
  
  <p>Here is inspector image</p>
  
  <p><a href="https://i.stack.imgur.com/7Olqy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7Olqy.png" alt="ChromeDevTool debug"></a></p>