There is a PHP file containing a formulaire <form which contains a file field :
<input type="file" name="doc_fichier" maxlength="255" size="50"> .
When I open the page with Firefox then the field is well displayed as shown in this captured image :

But when I open the page with Google Chrome then I got this :

So how to do so that Google Chrome displays the element correctly ?
There is no “correctly” way to display a file field, it is browser-dependant.
Your screenshot is the standart way of displaying a file field in Chrome.