checkbox not showing in chrome and android

I have a simple checkbox that is showing on FF but not in chrome or anroid or iphone browser.

<label for="isCommentAnonymous" class="control-label com-vp-chk"><input type="checkbox" id="isCommentAnonymous" class="checkbox-inline com-vp-lbl" /> Post anonymously</label>

NOt sure what is wrong i looked for few tutorian tried few option but i cant see check box.

TRied

input[type=checkbox]
{
/*-webkit-appearance: none;*/
  -webkit-appearance:checkbox;
}