Bug 1629205 - Context menu action show number of tabs affected by close. r=flod,dao

The context menu show the number of tabs affected by the close => Close N tabs.

Differential Revision: https://phabricator.services.mozilla.com/D120986

browser/base/content/main-popupset.inc.xhtml

@@ -68,7 +68,7 @@
               oncommand="gBrowser.selectAllTabs();"/>
     <menuseparator/>
     <menuitem id="context_closeTab"
-              data-lazy-l10n-id="tab-context-close-tabs"
+              data-lazy-l10n-id="tab-context-close-n-tabs"
               data-l10n-args='{"tabCount": 1}'
               oncommand="TabContextMenu.closeContextTabs();"/>
     <menu id="context_closeTabOptions"

browser/locales/en-US/browser/tabContextMenu.ftl

@@ -80,11 +80,11 @@ tab-context-reopen-closed-tabs =
            *[other] Reopen Closed Tabs
         }
     .accesskey = o
-tab-context-close-tabs =
+tab-context-close-n-tabs =
     .label =
         { $tabCount ->
             [1] Close Tab
-           *[other] Close Tabs
+           *[other] Close { $tabCount } Tabs
         }
     .accesskey = C
 tab-context-move-tabs =