cocoa browser: remove non-MD bookmark bar support

chrome/browser/ui/cocoa/bookmarks/bookmark_bar_folder_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_bar_folder_button_cell.h"
 
 #include "ui/base/material_design/material_design_controller.h"
 
 using bookmarks::BookmarkNode;
 
@@ skipping 13 matching lines @@
 }
 
 - (BOOL)isFolderButtonCell {
   return YES;
 }
 
 - (void)setMouseInside:(BOOL)flag animate:(BOOL)animated {
 }
 
 - (int)verticalTextOffset {
-  if (!ui::MaterialDesignController::IsModeMaterial()) {
-    return [super verticalTextOffset];
-  }
   return -3;
 }
 
 @end