Triggering JavaScript from back-end event
When an entry is saved, an Entry saved. flash message is set and displayed by Craft. You could use the Control Panel JS plugin to write a script to detect this flash message and perform your desired action.

The flash message is set in a div with an id="notifications". When there is no notification present, this div is empty. When there is a notification present, the div contains another div like this:

&lt;div id="notifications"&gt;
    &lt;div class="notification notice" style="opacity: 0; display: none;"&gt;Entry saved.&lt;/div&gt;
&lt;/div&gt;


If you test for the presence of this inner div and also the specific notification content (i.e. Entry saved.) you should be able to trigger the actions you need to.