[MD Bookmarks] Remove the bookmarks-sidebar element.

chrome/browser/resources/md_bookmarks/compiled_resources2.gyp

 # Copyright 2016 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.
 {
   'targets': [
     {
       'target_name': 'actions',
       'dependencies': [
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:cr',
         '<(EXTERNS_GYP):chrome_extensions',
@@ skipping 97 matching lines @@
     },
     {
       'target_name': 'router',
       'dependencies': [
         'actions',
         'store_client',
       ],
       'includes': ['../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
-      'target_name': 'sidebar',
-      'dependencies': [
-        'store_client',
-      ],
-      'includes': ['../../../../third_party/closure_compiler/compile_js2.gypi'],
-    },
-    {
       'target_name': 'store',
       'dependencies': [
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:cr',
         '<(EXTERNS_GYP):chrome_extensions',
         'reducers',
         'types',
       ],
       'includes': ['../../../../third_party/closure_compiler/compile_js2.gypi']
     },
     {
@@ skipping 29 matching lines @@
       'target_name': 'util',
       'dependencies': [
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:cr',
         '<(EXTERNS_GYP):chrome_extensions',
         'types',
       ],
       'includes': ['../../../../third_party/closure_compiler/compile_js2.gypi']
     }
   ]
 }