title: onEndReached in Flatlist issue
body: <p>If I enclose the flatlist in a View then my onEndReached triggers infinitely if I remove the enclosing View onEndReached is not triggered at all.</p>
  
  <pre><code> render() {
      return (
          &lt;Root&gt;
              &lt;Container&gt;
                  &lt;Content&gt;
                      &lt;View&gt;
                          {this.state.listView &amp;&amp; (
                              &lt;FlatList
                                  data={this.state.variants}
                                  keyExtractor={this._keyExtractor}
                                  onEndReachedThreshold={0.5}
                                  onEndReached={({ distanceFromEnd }) =&gt; {
                                      console.log(
                                          "on end reached ",
                                          distanceFromEnd
                                      );
                                      this.loadMore();
                                  }}
                                  numColumns={1}
                                  renderItem={({ item, index }) =&gt; (
                                      &lt;CatalogRow
                                          item={item}
                                          in_wishlist={this.state.in_wishlist}
                                          toggleWishlist={() =&gt;
                                              this.toggleWishlist(item.title)
                                          }
                                          listView={this.state.listView}
                                      /&gt;
                                  )}
                              /&gt;
                          )}
                      &lt;/View&gt;
                  &lt;/Content&gt;
              &lt;/Container&gt;
          &lt;/Root&gt;
      );
  }
  </code></pre>
  
  <p>And my <code>distanceFromEnd</code> takes values like 0 , 960,1200 when it is trigerred. What does it indicate?
  I'm using  react-native 0.47.2</p>