title: Why context2d.backingStorePixelRatio deprecated?
body: <p>According to Paul Lewis's article, <a href="http://www.html5rocks.com/en/tutorials/canvas/hidpi/" rel="noreferrer"><em>High DPI Canvas</em></a>: You need to take into account the <code>context.backingStorePixelRatio</code> to solve blurring issues. </p>
  
  <p>If this property was deprecated, will dart take care of the blur issue on high definition device?</p>