Bug 1259389 - "Restore closed windows" items without url have additional indent at the left, r=Gijs.

MozReview-Commit-ID: 17Ubpm9VDVA

--HG--
extra : rebase_source : 4fbce51414565d63c1bad44da6abf06e9861c418

browser/components/customizableui/CustomizableWidgets.jsm

@@ -253,7 +253,7 @@ const CustomizableWidgets = [
       let elementCount = tabsFragment.childElementCount;
       separator.hidden = !elementCount;
       while (--elementCount >= 0) {
-        tabsFragment.children[elementCount].classList.add("subviewbutton");
+        tabsFragment.children[elementCount].classList.add("subviewbutton", "cui-withicon");
       }
       recentlyClosedTabs.appendChild(tabsFragment);
 
@@ -263,7 +263,7 @@ const CustomizableWidgets = [
       elementCount = windowsFragment.childElementCount;
       separator.hidden = !elementCount;
       while (--elementCount >= 0) {
-        windowsFragment.children[elementCount].classList.add("subviewbutton");
+        windowsFragment.children[elementCount].classList.add("subviewbutton", "cui-withicon");
       }
       recentlyClosedWindows.appendChild(windowsFragment);
     },