title: Flickering issue with antd
body: <p>I am using the Ant Design components for some interfaces in a React App but I'm noticing an issue with Modals and Tooltips. Usually when the modal is empty or is simple - e.g has only a text it is going to show properly but in case there are more elements on it (on production scenario) it flickers. </p>
  
  <p>You can visually watch the flickering issue here: <a href="https://drive.google.com/file/d/1ODsj-aGz6saHJLXLI7sJaesgHKKPrvD2/view" rel="nofollow noreferrer">https://drive.google.com/file/d/1ODsj-aGz6saHJLXLI7sJaesgHKKPrvD2/view</a></p>
  
  <p>Hope to get some answers :-) Thank you!
  The visibleRequest state variable is triggered true by a button in the interface.
  EDIT: As requested here's my code: </p>
  
  <pre><code>renderRequests=()=&gt;{
          const data = [
              {name:"Request #1",description:"Request description",status:"0"},
              {name:"Request #1",description:"Request description",status:"1"},
              {name:"Request #1",description:"Request description",status:"2"}
          ];
          const handleOk = ()=&gt;{
              console.log("Submitted");
              this.setState({visibleRequest:false})
          }
          const handleCancel = ()=&gt;{
              this.setState({visibleRequest:false})
          }
          return(
              &lt;div style={{overflowY:"scroll"}}&gt;
              &lt;Modal
                  title="Submit new request"
                  visible={this.state.visibleRequest}
                  onOk={handleOk}
                  onCancel={handleCancel}
                  &gt;
                  &lt;Input placeholder="Title"/&gt;
                  &lt;Input.TextArea placeholder="Description"/&gt;
                  &lt;DatePicker/&gt;
              &lt;/Modal&gt;
                  &lt;List 
                      dataSource={data}
                      renderItem={item=&gt;{
                          return(
                              &lt;List.Item&gt;
                                  &lt;List.Item.Meta
                                  title={item.name}
                                  description={item.description}
                                  /&gt;
                                  {item.status==1?&lt;Tooltip title="Request approved"&gt;
                                  &lt;Icon type="check-circle" theme="twoTone" twoToneColor="#52c41a" /&gt;
                                  &lt;/Tooltip&gt;:
                                  item.status==2?&lt;Icon type="close-circle" theme="twoTone" twoToneColor="#7F1C43" /&gt;:&lt;Icon type="ellipsis" theme="outlined" /&gt;}
                              &lt;/List.Item&gt;
                          )
                  }}/&gt;
                  &lt;Pagination total={20}/&gt;
              &lt;/div&gt;
          )
      }
  </code></pre>