title: React Native: Not smooth scrolling with DrawerNavigator
body: <h1>Current Behavior</h1>
  
  <p>My code:</p>
  
  <pre><code>class App extends Component {
     render() {
      return &lt;Drawer /&gt; {/* rigid scrolling effect */} 
      return &lt;Stack /&gt; {/* smooth scrolling effect if I comment above return statement */} 
    }
  }
  
  const Drawer = DrawerNavigator({
    Feed: { screen: Feed }
  })
  
  const Stack = StackNavigator({
    Feed: { screen: Feed }
  })
  </code></pre>
  
  <p>And Feed component's render is just a bunch of lines:</p>
  
  <pre><code>render() {
     return &lt;View style={{flex:1}}&gt;
     &lt;ScrollView&gt;
      &lt;Text&gt;random line...&lt;/Text&gt;
     // .. more lines to make it scrollable
     &lt;/ScrollView&gt;
     &lt;/View&gt;
  }
  </code></pre>
  
  <h1>Expected Behavior</h1>
  
  <p>The expected behavior is to get smooth scrolling effect in both cases. However, DrawerNavigator screen's scrolling effect is extremely rigid. When I swipe my finger quickly from up to down, it doesn't keep scrolling smoothly automatically like it should in Stacknavigator example.</p>
  
  <h1>How to reproduce</h1>
  
  <p>Create App.js file above and create a simple Feed.js component which has a bunch of lines to make ScrollView work.</p>
  
  <p>Can anybody help?</p>
  
  <p><strong>Update:</strong> Live demonstration: <a href="https://snack.expo.io/Hk8Np7nPG" rel="nofollow noreferrer">https://snack.expo.io/Hk8Np7nPG</a></p>