Bug 1591242 - Hide megabar search icon in popups. r=adw

Differential Revision: https://phabricator.services.mozilla.com/D50625

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

browser/base/content/browser.xhtml

@@ -864,7 +864,8 @@
             <hbox id="urlbar-input-container"
                   flex="1"
                   pageproxystate="invalid">
-              <box id="urlbar-search-icon"/>
+              <box id="urlbar-search-icon"
+                   class="chromeclass-toolbar-additional"/>
               <!-- Use onclick instead of normal popup= syntax since the popup
                    code fires onmousedown, and hence eats our favicon drag events. -->
               <box id="tracking-protection-icon-container" align="center"

browser/themes/shared/urlbar-searchbar.inc.css

@@ -159,6 +159,10 @@
   display: block;
   position: absolute;
   inset: 0;
+}
+
+:root:not([chromehidden~="toolbar"]) #urlbar.megabar:not([breakout]) > #urlbar-background,
+:root:not([chromehidden~="toolbar"]) #urlbar.megabar:not([breakout-extend]) > #urlbar-background {
   inset-inline-start: @urlbarSearchIconWidth@;
 }
 
@@ -202,7 +206,6 @@
 
 #urlbar[breakout][breakout-extend] > #urlbar-background {
   box-shadow: 0 5px 18px rgba(0, 0, 0, .2);
-  inset-inline-start: 0;
 }
 
 #urlbar[breakout][breakout-extend] > #urlbar-input-container {