String relativePath

Source 

@DomName('File.webkitRelativePath')
@DocsEditable()
@SupportedBrowser(SupportedBrowser.CHROME)
@SupportedBrowser(SupportedBrowser.SAFARI)
@Experimental()
// https://plus.sandbox.google.com/+AddyOsmani/posts/Dk5UhZ6zfF3
String get relativePath =>
    _blink.BlinkFile.instance.webkitRelativePath_Getter_(this);