chromium/content/test/data/accessibility/html/input-image.html

<!--
@BLINK-ALLOW:default
@BLINK-ALLOW:inputType=*
@MAC-ALLOW:AXRoleDescription
@WIN-ALLOW:DEFAULT
@WIN-ALLOW:xml-roles*
@WIN-ALLOW:text-input-type*
@AURALINUX-ALLOW:text-input-type:*
@AURALINUX-ALLOW:default
@AURALINUX-ALLOW:xml-roles*
-->
<!DOCTYPE html>
<html>
<body id="body">
    <input type="image" alt="Submit" src="greenbox.png" width=100 height=100>
</body> 
</html>