Bug 803336 - Social API toolbar button needs more horizontal margins on Mac. r=felipe

browser/themes/pinstripe/browser.css

@@ -4043,8 +4043,17 @@ html|*#gcli-output-frame {
   -moz-box-orient: horizontal;
 }
 
-#social-toolbar-item > .toolbarbutton-1 {
-  margin: 0px;
+#social-toolbar-item > .toolbarbutton-1:not(:first-child):not(:last-child) {
+  margin-left: 0;
+  margin-right: 0;
+}
+
+#social-toolbar-item > .toolbarbutton-1:first-child {
+  -moz-margin-end: 0;
+}
+
+#social-toolbar-item > .toolbarbutton-1:last-child {
+  -moz-margin-start: 0;
 }
 
 .social-notification-icon-hbox {