Show a separator in the combobox of Bookmark Bubble.

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

 // Copyright (c) 2012 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_bubble_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/chrome_bookmark_client.h"
@@ skipping 314 matching lines @@
 }
 
 // Fill in all information related to the folder pop up button.
 - (void)fillInFolderList {
   [nameTextField_ setStringValue:base::SysUTF16ToNSString(node_->GetTitle())];
   DCHECK([folderPopUpButton_ numberOfItems] == 0);
   [self addFolderNodes:model_->root_node()
          toPopUpButton:folderPopUpButton_
            indentation:0];
   NSMenu* menu = [folderPopUpButton_ menu];
+  [menu addItem:[NSMenuItem separatorItem]];
   NSString* title = [[self class] chooseAnotherFolderString];
   NSMenuItem *item = [menu addItemWithTitle:title
                                      action:NULL
                               keyEquivalent:@""];
   ChooseAnotherFolder* obj = [[self class] chooseAnotherFolderObject];
   [item setRepresentedObject:obj];
   // Finally, select the current parent.
   NSValue* parentValue = [NSValue valueWithPointer:node_->parent()];
   NSInteger idx = [menu indexOfItemWithRepresentedObject:parentValue];
   [folderPopUpButton_ selectItemAtIndex:idx];
@@ skipping 54 matching lines @@
   NSInteger idx = [menu indexOfItemWithRepresentedObject:parentValue];
   DCHECK(idx != -1);
   [folderPopUpButton_ selectItemAtIndex:idx];
 }
 
 - (NSPopUpButton*)folderPopUpButton {
   return folderPopUpButton_;
 }
 
 @end  // implementation BookmarkBubbleController(ExposedForUnitTesting)