Empty tooltip populated dynamically is not formatted correctly

[BrianPopeck]

Description

A 'paper-tooltip' element whose textContent is dynamically changed from empty to nonempty does not display correctly. The text is not formatted and is displayed on screen regardless of the cursor position.

Expected outcome

The dynamically populated tooltip looks identical to a static tooltip.

Actual outcome

Incorrect formatting.

<button id="refreshBtn">Refresh</button>
<paper-tooltip id="refreshTooltip" for="refreshBtn"></paper-tooltip>

<script>
    document.getElementById("refreshBtn").addEventListener("click", function() {
        let tooltip = document.getElementById("refreshTooltip");
        tooltip.textContent = "some text after refresh";
    });
</script>

Browsers Affected

• Chrome
• Firefox
• Safari 9
• Safari 8
• Safari 7
• Edge
• IE 11
• IE 10