Vertical space error when two div at the same position only under chrome

Question

Under the chrome, I posit two div to the same position with the inline-flex, however I found the little white gap between them, and under the IE or Safari, it looks like the correct, however I could not found out the reason!

<div class="tips"><div class="time">2小时前</div><div class="gap"></div> 
<div class="-progressbarWrapper"><div class="progressbar"><div 
class="progressbar-inner" style="width:58%"></div></div></div></div>

* {
    margin: 0;
    padding: 0;
}


.gap {
    height: 12px;
    background-color: #999999;
    width: 1px;
    margin: 0 5px;
}

.tips {
    height: 16px;
    margin-top: 1px;
    font-size: 12px;
    line-height: 14px;
    display: flex;
    justify-content: center;
    align-items: center;
    color: #999999;
}

.time {
    width: 76px;
    text-align: right;
}

.progressbarWrapper {
    width: 74px;
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
}

.progressbar {
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    width: 25px;
    height: 7px;
    border: 1px solid #333333;
    box-sizing: border-box;
    word-spacing: 0;
    font-size: 0;
}

.progressbar-inner {
    display: inline-flex;
    height: 5px;
    background-color: limegreen;
    word-spacing: 0;
    font-size: 0;
}

http://jsfiddle.net/81k063gt/3/