Bug 1602624, move buttons down a bit to add room so that the larger themed popup can fit aligned in the available window space in ubuntu18.04, r=bgrins

Differential Revision: https://phabricator.services.mozilla.com/D58461

--HG--
extra : moz-landing-system : lando

toolkit/content/tests/chrome/window_popup_attribute.xhtml

@@ -12,7 +12,7 @@
 window.opener.SimpleTest.waitForFocus(runTests, window);
 </script>
 
-<hbox style="margin-left: 200px; margin-top: 270px;">
+<hbox style="margin-left: 200px; margin-top: 290px;">
   <label id="trigger" popup="thepopup" value="Popup" height="60"/>
 </hbox>
 <!-- this frame is used to check that document.popupNode

toolkit/content/tests/chrome/window_popup_button.xhtml

@@ -12,7 +12,7 @@
 window.opener.SimpleTest.waitForFocus(runTests, window);
 </script>
 
-<hbox style="margin-left: 200px; margin-top: 270px;">
+<hbox style="margin-left: 200px; margin-top: 290px;">
   <button id="trigger" type="menu" label="Popup" width="100" height="50">
     <menupopup id="thepopup">
       <menuitem id="item1" label="First"/>