title: New input placeholder behavior in Safari 10 - no longer hides on change via JavaScript
body: <p>Safari 10.0 in macOS Sierra seems to have changed the way the placeholder in an input behaves when the input value is changed via JavaScript. It now also differs from what Chrome (53.0.2785.116) is doing.</p>
  
  <p><strong>Until now,</strong> when setting an input value via JavaScript the placeholder would disappear. After setting the value back to empty via JavaScript, the placeholder would reappear.</p>
  
  <p><strong>Now,</strong> setting the input value via JavaScript does not hide the placeholder, until the input gains focus afterwards (e.g. by being clicked on). </p>
  
  <p>Check this JS Bin for a demo: <a href="https://jsbin.com/rogoludahu/edit?html,js,output" rel="noreferrer">https://jsbin.com/rogoludahu/edit?html,js,output</a></p>
  
  <p>Is this the intended behavior? If so, is there a clever workaround for hiding/unhiding the placeholder after a change via JavaScript?  </p>
  
  <p>Edit: This has now been filed at rdar://28412751 for Safari 10 and the Safari Technology Preview.</p>