More closely align palette to spec.

ui/gfx/vector_icons_sources.gypi

 # 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.
 
 {
   'variables': {
     'common': [
       'vector_icons/account_box.icon',
       'vector_icons/account_child.icon',
       'vector_icons/account_child_circle.icon',
@@ skipping 32 matching lines @@
       'vector_icons/find_prev.1x.icon',
       'vector_icons/find_prev.icon',
       'vector_icons/folder.1x.icon',
       'vector_icons/folder.icon',
       'vector_icons/folder_managed.1x.icon',
       'vector_icons/folder_managed.icon',
       'vector_icons/folder_supervised.1x.icon',
       'vector_icons/folder_supervised.icon',
       'vector_icons/fullscreen.icon',
       'vector_icons/globe.icon',
+      'vector_icons/help.icon',
       'vector_icons/help_outline.icon',
       'vector_icons/image.icon',
       'vector_icons/incognito.1x.icon',
       'vector_icons/incognito.icon',
       'vector_icons/info_outline.icon',
       'vector_icons/laptop.icon',
       'vector_icons/location_bar_http.1x.icon',
       'vector_icons/location_bar_http.icon',
       'vector_icons/location_bar_https_invalid.1x.icon',
       'vector_icons/location_bar_https_invalid.icon',
@@ skipping 166 matching lines @@
       'vector_icons/window_control_minimize.icon',
       'vector_icons/window_control_restore.1x.icon',
       'vector_icons/window_control_restore.icon',
       'vector_icons/window_control_right_snapped.1x.icon',
       'vector_icons/window_control_right_snapped.icon',
       'vector_icons/zoom_minus.icon',
       'vector_icons/zoom_plus.icon',
     ],
   },
 }