This hides all elements on the Google Maps page with a class of "noprint". It also hides the Minimap and Popular Times sections, which are undesirable for screenshots.

HideGoogleMapElementsForScreenshot.js

// Run this in the browser console window to prep Google Maps for screenshotting.
javascript: (function(e, s) {
    e.src = s;
    e.onload = function() {
        jQuery.noConflict();
	jQuery('.noprint,#minimap,.section-popular-times').hide();
    };
    document.head.appendChild(e);
})(document.createElement('script'), '//code.jquery.com/jquery-latest.min.js')