Bug 1388832 - Fix right-click on searchbar when in overflow menu. r=jaws

* Swap margins for paddings around the searchbar when in a menu. Elements that could precede and follow the searchbar all have margin: 0, and define top/bottom padding as 4px, so this seems reasonable
* Harden the loop that looks up a matching ancestor - break before we hit the document

MozReview-Commit-ID: LuniL3gdLWR

--HG--
extra : rebase_source : 2101be3215ff85f2cf15ba624fad5256c92e40e8

browser/base/content/browser.js

@@ -5430,7 +5430,8 @@ function onViewToolbarsPopupShowing(aEvent, aInsertPoint) {
   } else if (toolbarItem && toolbarItem.localName != "toolbar") {
     while (toolbarItem && toolbarItem.parentNode) {
       let parent = toolbarItem.parentNode;
-      if ((parent.classList && parent.classList.contains("customization-target")) ||
+      if (parent.nodeType !== Node.ELEMENT_NODE ||
+          (parent.classList && parent.classList.contains("customization-target")) ||
           parent.getAttribute("overflowfortoolbar") || // Needs to work in the overflow list as well.
           parent.localName == "toolbarpaletteitem" ||
           parent.localName == "toolbar")

browser/themes/shared/customizableui/panelUI.inc.css

@@ -1622,8 +1622,8 @@ toolbarpaletteitem[place="palette"] > .toolbarbutton-1 > .toolbarbutton-menubutt
 }
 
 #search-container[cui-areatype="menu-panel"] {
-  margin-top: 6px;
-  margin-bottom: 6px;
+  padding-top: 6px;
+  padding-bottom: 6px;
 }
 
 toolbarpaletteitem[place="palette"] > #search-container {