[Mac] Show context menu on empty BMB item.

chrome/browser/ui/cocoa/bookmarks/bookmark_button_cell.mm

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_button_cell.h"
 
 #include "base/logging.h"
 #include "base/strings/sys_string_conversions.h"
 #import "chrome/browser/bookmarks/bookmark_model.h"
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_button.h"
@@ skipping 165 matching lines @@
 - (void)setBookmarkNode:(const BookmarkNode*)node {
   [self setRepresentedObject:[NSValue valueWithPointer:node]];
 }
 
 - (const BookmarkNode*)bookmarkNode {
   return static_cast<const BookmarkNode*>([[self representedObject]
                                             pointerValue]);
 }
 
 - (NSMenu*)menu {
-  if (empty_)
-    return nil;
-
   // If node is NULL, this is a custom button, the menu does not represent
   // anything.
   const BookmarkNode* node = [self bookmarkNode];
 
   if (node && node->parent() &&
       node->parent()->type() == BookmarkNode::FOLDER) {
     content::RecordAction(UserMetricsAction("BookmarkBarFolder_CtxMenu"));
   } else {
     content::RecordAction(UserMetricsAction("BookmarkBar_CtxMenu"));
   }
@@ skipping 92 matching lines @@
               respectFlipped:YES
                        hints:nil];
   }
 }
 
 - (int)verticalTextOffset {
   return 0;
 }
 
 @end